Stormwater Bibliography Abstracts

Abt, S.R.; Thornton, C.I.; Johnson, T.L. "Estimating drainage area on steep uniform slopes." Water Resources Bulletin 31:1, 1995. 53-57.
Abstract: A study was conducted to derive a simple procedure for estimating the tributary drainage area that may potentially develop at the base of a uniformly graded, steep slope. Data were extracted from a rill development flume study in which 112 rills and their tributary drainage areas were documented. The tributary drainage area for each rill was correlated to the slope length and the slope gradient. The findings are considered applicable to planar, convex, and divergent slopes with lengths of up to 130 m. Field verification is needed to extend the applicability of the relation. 

Adams, Mason. Luck isn't enough: the fight for clean water. Westport, CT : Jacoby/Storm Productions, Inc., [1995?] 1 videocassette (12 min.).
Abstract: Focuses on the problem of polluted urban runoff and its impact on water quality and environmental health, and on ways to prevent and mitigate water pollution. 

Aholt, D.J.; Ritter, D.C. "Centrifugal Pumps" Industrial Wastewater Aug 1998. 41-44.
Abstract: When choosing a pump, wastewater treatment plant operators and engineers have many options. Some of the most common pumps are positive-displacement pumps, which operate a lot like air compressors and generally are used to move sludge and other materials requiring high-head, low-volume pumping; axial-flow and mixed-flow pumps, which create flow and head with a propeller and are used in low-head, high-volume applications; and centrifugal pumps, which use a rotating impeller to create internal pressure to transfer fluid. Centrifugal pumps are the most common pumps used for nonhazardous process wastewater, stormwater, and sanitary wastewater transfer because they are less expensive and require less maintenance than other types of pumps. 

Anderson, B.C.; Caldwell, R.J.; Crowder, A.A.; Marsalek, J.; Watt, W.E. "Design and operation of an aerobic biological filter for the treatment of urban stormwater runoff." Water Quality Research Journal of Canada 32:1, 1997. 119-139.
Abstract: The primary objective of this research was to develop a field-scale submerged aerobic biological filter (SABF) system for the treatment of urban stormwater runoff. The first phase involved development of a bench-scale laboratory SABE, which was used to examine the treatment processes and to establish operating parameters for the system. The second phase used these preliminary results to design, construct, install and assess the operation of a field-scale unit at the stormwater pond site. A third phase has involved long-term operation of the field system, and detailed examination of the influence of operational variables on system performance. This paper summarizes the findings from the lab-scale research and the first phase of field filter operation. Results indicate that the biotechnological treatment system may be suitable for the proposed application. The type of integrated management approach to urban stormwater, whereby a number of systems are used to achieve quantity and quality control, is currently being investigated at an existing on-line wet detention stormwater management pond in Kingston, Ontario. The site is appropriate because it is typical of many older ponds, in that it is on-line, it has inadequate size and an unfavourable length-to-width aspect ratio for effective stormwater quantity and quality control, and it discharges to a downstream sensitive coastal wetland area. 

Anon. "Catch basins reduce floatables." Public Works 129:11, Oct 1998. 14-17.
Abstract: For as long as there have been sewers in New York City, floatable trash such as cups, bottles, and cartons have been washed into the waters around the city, particularly after storms. These floatables originated from combined sewer overflows (CSOs), stormwater outfalls, derelict structures, landfills, and marine vessels. By 1985, the unsightly nuisance had grown into a significant problem. Illegal dumping was responsible for much of the problem, but even after most of that was stopped, too much street litter was still getting into the water. 

Anon. "EPA to Add 'Safety Valves' to Stormwater Program." Waterworld 14:6, Jun 1998. 1-2.
Abstract: The Environmental Protection Agency is working to revise the Phase II stormwater control program to install "safety valves" that would allow certain sources to be excluded from the national program if they can demonstrate they have no impact on water quality. Some sources not regulated on a national basis could be pulled into the program, however, to help combat localized problems with water quality. The existing National Pollutant Discharge Elimination System (NPDES) stormwater program (Phase I) has been in place for a number of years, helping improve surface water quality in the United States by reducing polluted runoff from a large number of priority sources, including major industrial facilities, large and medium city storm sewers ("municipal separate storm sewer system" or "MS4s"), as well as construction sites that disturb five or more acres. The Phase II stormwater regulations, which must be finalized by March 1, 1999, would expand the existing national program to smaller municipalities and construction sites that disturb one to five acres. 

Anon. "Stormwater Discharge Characterization." FEDRIP DATABASE, NATIONAL TECHNICAL INFORMATION SERVICE. Springfield, VA: NTIS, 1996.
Abstract: RPROJ/FEDRIP Describe, sample, analyze and characterize for the purpose of producing a permit application for 18 outfalls as per the requirements of the newly reissued National Pollutant Discharge Elimination System (NPDES) permit issued by the Illinois Environmental Protection Agency (IEPA). This will entail contracting services for the sampling and analytical portions of the project, and the in-house production of the permit application documents. The anticipated benefit to the Laboratory will be the continued capability to discharge wastewater at the 19 locations, without interruption of the Laboratory's operations. 

Arora, K.; Mickelson, S.K.; Baker, J.L.; Tierney, D.P.; Peters, C.J. "Herbicide retention by vegetative buffer strips from runoff under natural rainfall." Trans ASAE 39:6. St. Joseph, Mich.: American Society of Agricultural Engineers. Nov/Dec 1996. 2155-2162.
Abstract: Effectiveness of vegetative buffer strips for herbicide retention from agricultural runoff was evaluated in a two-year natural rainfall study. A source area of 0.41 ha (mainly Canisteo silty clay loam soil), having an average slope of 3%, was fall chisel-plowed, spring disked, and planted to corn. Three herbicides (atrazine, metolachlor, and cyanazine) were applied to the source area in each spring. Six vegetative buffer strips, 1.52 m wide X 20.12 m long, were isolated with metal borders downslope of the source area in a well established bromegrass (Bromus inermis) waterway. These strips provided for three replications of two drainage to buffer area ratio treatments of 15:1 and 30:1. Herbicide retention was dependent on the antecedent moisture conditions of the strips. These retentions ranged from 11 to 100% for atrazine, 16 to 100% for metolachlor, and 8 to 100% for cyanazine. Herbicide retention by the buffer strips for the two treatments were not significantly different for the observed storm events. Herbicide concentrations in solution in outflow from the strips were less than the inflow concentrations for all the three herbicides. Infiltration was the key process for herbicide retention by the buffer strips, although there was some adsorption to in-place soil and/or vegetation. Metolachlor concentrations in sediment increased in outflow for the two treatments; however, the opposite was true for atrazine and cyanazine. Herbicide retention by sediment deposition in the strip represented about 5% of the total herbicide retention by the buffer strips. The buffer strips were found to have high percent sediment retention, ranging from 40 to 100%; thus, the strips would be more effective for retaining strongly adsorbed herbicides. 

Balades, J.D.; Legret, M.; Madiec, H. "Permeable pavements: Pollution management tools." Water Science and Technology 32:1, 1995. 49-56.
Abstract: The latest tests on permeable road surfacing demonstrate the rate at which clogging occurs, according to the type of surface, and the best methods for recovering micro-pollutants. In the first year there is little change in underseepage rate but thereafter decline is rapid, reaching 50% of the original rate after 2 or 3 years. For highly permeable surfacing containing many spaces, absorption capacity remains high even after this period, but methods of preventive maintenance, such as suction, need to be used in order to avoid the use of even more costly methods, such as high pressure water jet with simultaneous suction. However, permeable surfacing does enable the storage and recovery of most micro-pollutants, thus preventing such particles being washed off into the ground. 

Ball, J.E.; Jenks, R.; Aubourg, D. "An assessment of the availability of pollutant constituents on road surfaces." Science of the Total Environment 209:2-3, Jan 1998. 243-254.
Abstract: The quality of stormwater runoff from the urban environment is of increasing concern to urban communities and, consequently, greater emphasis is now being placed on the management of stormwater quality. An essential need for this management is information about the drainage system and the impacts of alternative management approaches. This information, typically, is obtained through the use of catchment model systems which simulate the processes which influence both the quantity and quality of stormwater runoff. These model systems consist of a number of components with information flowing from one component to another; each of these components in turn comprised of process models. An important component of these systems for water quality modelling is the generation component where the mass of pollutant constituent available for transport during the storm event is estimated. Available information for use in the models applied to this task is extremely limited and, consequently, the poor reliability of this initial information is reflected in the reliability of the predictions obtained from the catchment model system. Presented herein are the results of a study investigating the build-up of pollutant constituents on a suburban road in the eastern suburbs of Sydney, Australia. It was found that the pollutant constituents available for transport during storm events were significantly different from previously published data for North America. Furthermore, it was found that both rain and wind events lowered the available pollutant constituent mass on the road surface. 

Barber M.E.; Schaftlein S.; Anderson D. "Stormwater Runoff Cost/Benefit Project: Prioritizing Stormwater Outfalls." Govt Reports Announcements & Index, Issue 03. Springfield, VA: NTIS, 1998.
Abstract: TD3: The goal of this research was to establish a scientifically justifiable approach for evaluating the benefits of environmental enhancement. The report documents the literature review and the Condition Indexing methodology adopted. A support program was developed for Windows 95 and NT operating systems that enables users to quickly evaluate and compare projects. The final result is a cost benefit ratio for each proejct. Since the costs associated with construction are well known, the gross benefit can also be determined. Final rept. Sponsored by Washington State Dept. of Transportation, Olympia., Federal Highway Administration, Olympia, WA. Washington Div. and Washington State Transportation Commission, Olympia. Planning and Programming Service Center. 

Barrett, Michael E.; Walsh, Patrick M.; Malina, Joseph F. Jr.; Charbeneau, Randall J. "Performance of vegetative controls for treating highway runoff." Journal of Environmental Engineering 124:11. Reston, VA: ASCE, Nov 1998.
Abstract: The capability of vegetated highway medians for treating stormwater runoff in the Austin, Texas area was studied. Two medians on major highways were monitored to document pollutant removal efficiencies. The medians were designed solely for stormwater conveyance and differed in slope and vegetation type. Removal efficiencies at the two sites were remarkably similar despite these differences and were comparable with those observed in structural controls such as sedimentation/filtration systems. 

Beitinger, E; Tarnowski, F; Gehrke, M; Burmeier, H. "Permeable treatment walls for in-situ groundwater remediation -- how to avoid precipitation and bio-clogging." International FZK/TNO Conference. ConSoil '98, Edinburgh (UK), 17-21 May 1998. Thomas Telford Publishing, 1998. 585-598.
Abstract: The design of permeable reactive barriers is discussed with reference preventing negative effects such as inflow of fine soil particles, precipitation of carbonates, iron and manganese, and loss of effectiveness by uncontrolled growth of biomass. A wall construction system including filter layers, permanent spacing for refillable reactive media and seals for stormwater- and air tightness is presented. Field test results are reported which show the system functions well and is effective at removing organic solvents from groundwater. 

Bertrand-Krajewski, J.L.; Chebbo, G.; Saget, A. "Distribution of pollutant mass vs volume in stormwater discharges and the first flush phenomenon." Water Research 32:8, Aug 1998. 2341-2356.
Abstract: The dimensionless M(V) curves indicating the distribution of pollutant mass vs volume in stormwater discharges are used to compare pollutant discharges from different rainfall events and catchments. The M(V) curves are very variable and dispersed for each pollutant and for a series of rainfall events in a given catchment. From the analysis of 197 rainfall events in 12 separate and combined sewer systems, the following results can be extracted: - in separate sewer systems, 80% of the total pollutant mass is transported in the first 74% of the total volume for 50% of the rainfall events; - in combined sewer systems, 80% of the total pollutant mass is transported in the first 79% of the total volume for 50% of the rainfall events. The characteristics of the M(V) curves depend on the pollutant, the site, the rainfall event and the functioning of the sewer system. No general multi-regression relationships can be established to explain their shape and their variability because of the complexity of the phenomena involved and the multiplicity of influencing factors. A new definition of the first flush is derived from the analysis of the M(V) curves, allowing a non-ambiguous quantification of a phenomenon which, up to now, was presented in a principally descriptive or qualitative manner. It is assumed that there is a significant first flush if at least 80% of the total pollutant mass is transported in the first 30% of the volume discharged during rainfall events. Previous definitions proposed by other authors are discussed with regard to the treatment of stormwater discharges. However, the concept of the first flush can not be used alone to establish a reliable methodology to design treatment facilities. Additional knowledge and information are necessary. From this point of view, the analysis of experimental M(V) curves is appropriate to base a design methodology which takes into account the intrinsic variability of the phenomena. 

Boller, M. "Tracking heavy metals reveals sustainability deficits of urban drainage systems." Water Science and Technology 35:9, 1997. 77-87.
Abstract: Heavy metals such as cadmium, copper, lead and zinc are the critical metals in domestic wastewaters. Based on mass flow studies, the runoff from roofs and streets contribute 50-80% of these metals to the total mass flow in domestic sewage. Depending on the sewerage concept, the metals accumulate in different environmental compartments. With the combined sewer system, most commonly applied, the major part of the metals is bound to the sludge during sewage treatment. If the sludge is used in agriculture, the metals are enriched slowly in the top soils. With separate sewer systems, the metal loads to the receiving waters are increased, finally leading to accumulation in the sediments. If the new concept for the infiltration of runoff waters is applied, rapid and concentrated accumulation at the infiltration sites will occur. As a short term measure, new adsorptive elements in infiltration facilities would allow us to control the accumulation. The deposition of heavy metals in the environment cannot be avoided as long as no further efforts are made to reduce metal emission at the source. New partnerships between environmental/sanitary engineers and other professional groups such as architects, plumbers, car engineers, material technologists have to be established in order to minimize diffuse longterm deposition of hazardous substances and to be able to realize sustainable small water cycles without negative side-effects. 

Booth, D.B.; Jackson, C.R. "Urbanization of aquatic systems: Degradation thresholds, stormwater detection, and the limits of mitigation." Journal of the American Water Resources Association 33:5, Oct 1997. 1077-1090.
Abstract: Urbanization of a watershed degrades both the form and the function of the downstream aquatic system, causing changes that can occur rapidly and are very difficult to avoid or correct. A variety of physical data from lowland streams in western Washington displays the onset of readily observable aquatic-system degradation at a remarkably consistent level of development, typically about ten percent effective impervious area in a watershed. Even lower levels of urban development cause significant degradation in sensitive water bodies and a reduced, but less well quantified, level of function throughout the system as a whole. Unfortunately, established methods of mitigating the downstream impacts of urban development may have only limited effectiveness. Using continuous hydrologic modeling we have evaluated detention ponds designed by conventional event methodologies, and our findings demonstrate serious deficiencies in actual pond performance when compared to their design goals. Even with best efforts at mitigation, the sheer magnitude of development activities falling below a level of regulatory concern suggests that increased resource loss will invariably accompany development of a watershed. Without a better understanding of the critical processes that lead to degradation, some downstream aquatic-system damage is probably inevitable without limiting the extent of watershed development itself. 

Bucheli, T.D.; Mueller, S.R.; Heberle, S.; Schwarzenbach, R.P. "Occurrence and behavior of pesticides in rainwater, roof runoff, and artificial stormwater infiltration." Environmental Science & Technology 32:22, 15 Nov 1998. 3457-3464.
Abstract: To prevent overloading of sewer systems and to ensure sufficient recharging of the groundwater underneath sealed urban areas, collection and artificial infiltration of roof runoff water has become very popular in many countries including Switzerland. However, there is still a considerable lack of knowledge concerning the quality of roof runoff, particularly with respect to the presence of pesticides. In this work, the occurrence and the temporal variations in concentration in rainwater and in roof runoff from different types of roofs (i.e., clay tile roofs, polyester roofs, flat gravel roofs) were determined for the most important members of three widely used classes of pesticides (i.e., triazines, acetamides, phenoxy acids). It is shown that in rain and roof runoff, maximum pesticide concentrations originating primarily from agricultural use occurred during and right after the application periods. Maximum average concentrations for single rain events and total loads per year were, for example, for atrazine, 903 ng/L and 13 900 ng/ (m super(2) year); for alachlor, 191 ng/L and 5900 ng/(m super(2) year); and for R-dichlorprop, 106 ng/L and 5100 ng/(m super(2) year). Further, the study reveals that a major portion of the compounds washed out from the atmosphere may actually reach the groundwater, particularly if the roof runoff is infiltrated directly into highly permeable zones of the subsurface. Nevertheless, although in some cases European Union and Swiss drinking water standards (100 ng/L) were not always met in rain and roof runoff waters, for the three compound classes investigated, the groundwater contamination potential of the pesticides originating from the atmosphere can be considered of equal or even smaller importance as compared to their direct use in agriculture. The investigations also show that leaching of pesticides used as construction chemicals on roofs, that is, as roof protection agents in sealings used on flat gravel roofs, may be a much more significant source of organic pollutants present in roof runoff. 

Butler, D.; Karunaratne, S.H.P.G. "The suspended solids trap efficiency of the roadside gully pot." Water Research 29:2, 1995. 719-729. 
Abstract: The roadside gully pot is a major component of many drainage systems used to protect the downstream sewers and receiving waters from excessive sediment deposits. This work aims to investigate the solids retention efficiency of a full size concrete pot by means of a laboratory test rig. Results from single-size quartz sand particles show that, for a given pot size, retention is influenced primarily by influent flow rate and particle diameter and to a lesser extent, retained sediment bed height. The major retention mechanism was postulated to be sedimentation within an hydraulically completely mixed environment. Transient re-erosion of the deposited bed was noted under extreme conditions with steady state concentrations never exceeding 10 mg/l. A model based on the proposed removal mechanisms was tested and shown to be in good agreement with the data. 

Charbeneau, R.J.; Barrett, M.E. "Evaluation of methods for estimating stormwater pollutant loads." Water Environment Research 70:7. Dec 1998. 1295-1302.
Abstract: This paper investigates a number of methods that can be used to generate constituent concentrations for use in stormwater modeling. These include the use of event mean concentrations (EMCs) and pollutant buildup and washoff formulations. Suspended solids data collected in the Austin, Texas, area from single-land-use watersheds were used to evaluate the usefulness of these methods. Use of a single EMC for all urban land uses was shown to provide a reasonable estimate of solids loads. This suggests that increases in total suspended solids loads resulting from development will be primarily a function of the increase in runoff volume, which in turn may be related to increased impervious cover. Water quality data did not indicate a strong correlation between initial pollutant load on the watershed and length of the antecedent dry period; however, the concentration of suspended solids in stormwater runoff does follow a simple washoff model. 

Chen, W.; Tan, S.K.; Tay, J.H. "Effects of heavy metals from urban runoff on the receiving water sediments." Conference paper. Water Pollution 3: Modelling, Measuring and Prediction, Porto Carras (Greece), Apr 1995. BILLERICA, MA: COMPUTATIONAL MECHANICS, INC., 1995. 415-422.
Abstract: The concentrations of heavy metals in the suspended and bed sediments in the urban receiving water, i.e., Kranji and MacRitchie reservoirs in Singapore were investigated. Distribution of heavy metals in the suspended sediments of different grain size was determined. The results show that more than 50% of heavy metals in the aquatic system are carried by suspended sediments in the urban runoff to the receiving waters. Heavy metals are most likely to be transported by particles of grain size > 1.2 mu m. Elevated concentration of heavy metals in the interstitial water of the bed sediment are potential threat to the quality of water and aquatic life. 

Christman, J.N.; Beverly, M.D. "Storm water permitting." J. ENVIRON. PERMITTING 4:3, 1995. 3-24.
Abstract: Until October 1, 1994, Section 402(p)(1) of the Clean Water Act (CWA) prohibited EPA from requiring National Pollutant Discharge Elimination System (NPDES) permits for all but a few (primarily industrial and certain municipal) dischargers of only storm water. Even though this moratorium has passed, EPA has not yet issued permitting regulations for these nonindustrial and (mostly) nonmunicipal dischargers of storm water. In an October 18, 1994, memorandum, EPA indicated that all storm-water-only dischargers without permits are now technically in violation of the CWA. How EPA will ultimately define the universe of dischargers requiring a permit is unclear. Although EPA says that it will not take enforcement action against those storm water dischargers formerly subject to the moratorium, they are still subject to citizen suits. Thus, with the status of the "Category 11" exemption for light industry unsettled and Congress considering reform of statutory storm water provisions, uncertainty prevails for many industrial and commercial point source dischargers of storm water. 

Christou, P.A. "Stormwater regulations: Five years later." Environmental Protection 8:12, Dec 1997. 16-18.
Abstract: It has been more than five years since the U.S. Environmental Protection Agency required industries and municipalities to obtain stormwater permits for the first time. How does the stormwater program affect your industrial facility now? 

Cornell University Educational Television Center. Constructed wetlands for the management of stormwater runoff. Ithaca, N.Y.: Educational Television Center, Cornell University Media Services, c1997. 1 videocassette (106 min.) 
Abstract: Reviews three constructed wetlands case studies in New York State, followed by three presentations and panel discussion with call/fax questions from the satellite broadcast downlink sites. 

Crunkilton, R.L.; DeVita, W.M. "Determination of aqueous concentrations of polycyclic aromatic hydrocarbons (PAHs) in an urban stream." Chemosphere 35:7, Oct 1997. 1447-1463.
Abstract: The concentrations of freely dissolved polycyclic aromatic hydrocarbons (PAHs) in an urban stream at high-flow and base-flow were estimated by an equilibrium partitioning model (EPM), and by use of lipid-filled semipermeable membrane devices (SPMDs), then compared to direct measurements made on bulk (unfiltered) water samples. The SPMD method was slightly more effective in detecting smaller three- and four-ring PAHs and the EPM method was slightly more effective in detecting five and six-ring PAHs. Although the SPMDs sequestered slightly fewer of the large PAHs, they sampled more compounds of a size range likely to be bioavailable to aquatic organisms. Estimates of the concentrations of freely dissolved PAHs for the EPM and the SPMD methods were similar when compared under the same flow regimes. The SPMD method also provided a time-integrated average measure of freely dissolved PAHs that cannot be easily duplicated with conventional sampling procedures. Concentrations of freely dissolved PAHs (EPM method) as well as concentrations of total PAHs at high-flow averaged about 20 times greater than at base-flow. This suggests the potential for immediate toxicological impacts on stream biota is greater at high-flow because of increased concentrations of bioavailable PAHs. For individual PAHs, differences between bulk and freely dissolved concentrations were most evident at high-flow for high K sub(ow) compounds strongly partitioned to suspended solids. Thus, in hazard assessments for aquatic biota it is important to employ measures of freely dissolved PAHs during storm water runoff events. 

DeCarr, W.K.; Sauda, D.F.; Hare, P.W. "In-line sparging." Industrial Wastewater, Aug 1998. 37-40.
Abstract: Sparging air into water to remove volatile organic compounds (VOCs) has been used for many years in both in situ and ex situ applications, including treatment of contaminated stormwater. Sparging can be used within an existing storm sewer system, avoiding the need to construct a large retention basin or aboveground treatment system. Only a small equipment enclosure is needed, and operation and maintenance costs are minimal. The simplicity and reliability of in-line sparging makes it an attractive alternative treatment for VOC-contaminated stormwater. 

Deletic, A. "The first flush load of urban surface runoff." Water Research 32:8, Aug 1998. 2462-2470.
Abstract: The treatment of urban surface runoff is steadily becoming common practice. Good management of treatment works requires an understanding of the first flush phenomenon of wet weather flow in urban drainage systems. The objective of this paper is to analyse evidence for the existence and nature of the first flush load of pollution input into drainage systems, using data on suspended solids, conductivity, pH, and temperature of storm surface runoff. The data were collected continuously for almost a year for single road inlets at two urban asphalt catchments (in Belgrade, Yugoslavia and Lund, Sweden). Cumulative load curves were constructed for all monitored water quality characteristics, and the pollution load carried by the first 20% of runoff, FF sub(20), was calculated for each recorded event. FF sub(20) values were analysed using standard statistical methods, including multiple regression. Only slight first flush effects for suspended solids and conductivity of storm runoff were observed at both catchments. No first flush effect was recorded for pH or temperature. The rainfall and runoff characteristics which influence the first flush phenomenon are different at each catchment studied, although the catchments have very similar characteristics. It was concluded that: (1) the first flush, if strongly present at the end of a drainage system, is not generated by the first flush of pollution input; (2) regression curves are not very reliable for prediction of the first flush load of pollution input into drainage systems.

Deletic, A.B.; Maksimovic, C.T. "Evaluation of water quality factors in storm runoff from paved areas." Journal of Environmental Engineering 124:9, Sep 1998. 869-880.
Abstract: Continuous water quality measurements of storm runoff into a single road inlet have been carried out at two experimental catchments, in Belgrade, Yugoslavia, and Lund, Sweden. Both sites were equipped with similar instrumentation for measurements of overland flow, turbidity, pH, conductivity, and temperature. The data were recorded at 10-s time intervals during rainfall events. To measure suspended solids concentration, turbidity meters were calibrated in conditions very similar to the real world. A detailed description of the field-measuring facilities used in the Belgrade catchment and the results of the measurements from both sites are presented. After detailed examination of possible errors in measurement, only the reliable data were used for statistical analysis. Event mean, extreme, and aggregated values were analyzed. The results indicate that the antecedent dry weather period length has only a minor effect upon road sediments wash-off, but it has an influence upon conductivity. The "first-flush effect" of suspended solids appears only in a limited number of events. Cross-correlation coefficients of rainfall, overland flow, and water quality were calculated for each event, taking into account the time lag between observed characteristics. These coefficients showed that suspended solids loading rate is influenced by rainfall intensity and overland flow rate. The results presented in this paper have been used in development of the physically based wash-off model published by Deletic and coworkers. 

Duke, L.D.; Chung, Y.J. "Industrial storm water pollution prevention: Effectiveness and limitations of source controls in the transportation industry." Waste Management 15:8, 1995. 543-558.
Abstract: Industrial activities that are sources of pollutants in storm water runoff at typical facilities of the transportation industry are identified by site investigations at five facilities. This research then evaluates pollution prevention measures implemented to reduce those pollutants, as required by storm water regulations under the U.S. Clean Water Act. Activities that potentially generate storm water pollutants, particular to facilities of this industry, include: vehicle maintenance; vehicle fueling; vehicle washing; and activities on paved access roads and vehicle storage areas. Activities common to this industry, but also found in other industries, include: storage and handling of process materials and wastes; operation of industrial equipment located outdoors or exposed to storm water; and design and operation of site drainage facilities. Most control measures cited in the compliance documents of the facilities in the case studies were not developed specifically for storm water pollution prevention, but serve to reduce storm water pollutants as part of compliance with regulations for hazardous waste, wastewater, worker safety, or other purposes. Most identified control measures were operational practices or employee procedures, rather than structural facility modifications or devices to remove pollutants. Implementation of such measures is difficult to enforce or verify by regulatory agencies, and evidence at the case study facilities suggests that measures described similarly at different facilities are unevenly implemented and unequally effective at controlling storm water pollutants. 

Eldridge L.L. "A-01 metals in stormwater runoff evaluation." Govt Reports Announcements & Index, Issue 15. Springfield, VA: NTIS, 1998.
Abstract: TD3: As a part of the A-01 investigation required by the NPDES permit, an investigation was performed to ascertain the concentrations of metals specifically copper (Cu), lead (Pb), and zinc (Zn) in stormwater being discharged through the outfall. This information would indicate whether all water being discharged would have to be treated or if only a portion of the discharged stormwater would have to be treated. A study was designed to accomplish this. The first goal was to determine if the metal concentrations increased, decreased, or remained the same as flow increased during a rain event. The second goal was to determine if the concentrations in the storm water were due to dissolved. The third goal was to obtain background data to ascertain if effluent credits could be gained due to naturally occurring metals.Samples from this study were analyzed and indicate that the copper and lead values increase as the flow increases while the zinc values remain essentially the same regardless of the flow rate. Analyses of samples for total metals, dissolved metals, TSS, and metals in solids was complicated because in all cases metals contamination was found in the filters themselves. Some conclusions can be derived if this problem is taken into account when analyzing the data. Copper concentrations in the total and dissolved fractions as well as the TSS concentrations followed the hydrograph at this outfall but the copper in solids concentration appeared to peak in the first flush and decline to nondetectable rapidly over the course of the storm event. Lead was present in the total analysis but not present in the dissolved fraction or the solids fraction of the samples. The data for zinc was interesting in that the dissolved fractions were higher than the total fraction in three out of four samples. This is probably due to the high zinc concentrations on the filters being transferred to the dissolved faction of the sample. (Abstract Truncated) Sponsored by Department of Energy, Washington, DC. 

Ellis, J.B.; Marsalek, J. "Overview of urban drainage: Environmental impacts and concerns, means of mitigation and implementation policies." Journal of Hydraulic Research/Journal de Recherches Hydraulique 34:6, 1996. 723-732.
Abstract: Recent developments in urban storm drainage are reviewed starting with drainage impacts on receiving waters, followed by a brief analysis of selected components of urban drainage systems, hydroinformatics, and regulatory programs. Further advancement in drainage planning will require considerations of the catchment, drainage system, groundwater, treatment plant and receiving waters as one entity, and ensuring sustainable integrated development and ecological enhancement of urban streams and corridors. Such processes should be based on comprehensive modelling, which is well advanced for hydrological aspects, but further development is needed in water quality, sediment quality, transport and impacts, and ecological modelling. Mitigation of stormwater impacts is accomplished by best management practices, which form a part of the treatment train, and their sustainability has to be ensured by proper operation and maintenance. Impacts of combined sewer overflow are mitigated either conventionally by storage (and return to the central wastewater treatment plant), or more recently, by satellite treatment or pollution separation at the overflow points. An improved utilization of the available spare (idle) capacities in the drainage system can be achieved by real-time control. Finally, regulatory programs in various countries indicated that a great deal of uncertainty and some aspects of such programs may even impede effective environmental practices. 

EPA. Protecting naturals wetlands. A guide to stormwater best management practices. US EPA OFFICE OF WATER, WASHINGTON, D.C., Oct 1996.
Abstract: Although wetlands have long been recognized for their flood control and water quality improvement functions, there is an increasing concern that unrestricted use of natural wetlands as receptacles for point and nonpoint sources of pollution, such as urban stormwater and other diffuse sources of runoff, will have an adverse effect on wetlands and wetland biota. As a result of this concern, the U.S. Environmental Protection Agency (EPA), in cooperation with the State of Florida, the Association of State Floodplain Managers, Inc., and the Association of State Wetland Managers, sponsored a workshop in January 1992 on wetlands and stormwater. The purpose of the workshop was to investigate various issues related to the management of stormwater and wetlands, explore potential options, and learn from the experiences of the participants (wetland scientists, engineers, and environmental managers) about protection of natural wetlands that receive stormwater runoff. 

Ferguson, B. Introduction to stormwater: Concept, purpose, design. New York: John Wiley & Sons, 1998.
Abstract: Stormwater management is an essential component of all landscape architecture and site engineering projects. Introduction to Stormwater helps solve environmental problems that arise in the process of planning, implementing, and evaluating the built environment. This useful guide is of singular importance to landscape architects, civil engineers, architects, wetlands scientists, and other environmental professionals who must comply with ever-changing government regulations. Concepts such as drainage, runoff quality, and drought control are presented in an easy-to-learn, nontechnical format, using case studies drawn from all regions of the United States. Over 200 charts, tables, photographs, and examples aid in conceptualization and calculations. Each chapter contains exercises to ensure that the user acquires applied skills essential to professional licensure exams and practice in the field, as well as information on related software. 

Field, R.; Averill, D.; O'Connor, T.P.; Steel, P. "Vortex separation technology." Water Quality Research Journal of Canada 32:1, 1997. 185-214.
Abstract: Several types of vortex separators have been developed during the last 30 years.Their major function has been to provide both flow regulation and settleable solids concentration for the control of combined sewer overflows (CSOs). A variety of opinions have developed regarding the application of these technologies, ranging from overwhelming support to reservations of their effectiveness. The performance of vortex devices depends on the settling velocity distribution of the particles in the wastewater. When correctly installed with other controls in combined sewer or separate stormwater systems, vortex devices can play an important role in the control of pollution from CSO and stormwater discharge. Reliable determination of performance depends principally upon accurate sampling techniques, suspended solids and other pollutant analyses, and the settling velocity distributions of the influent and effluent. Simultaneous flow rate measurement, synchronized to sampling time, is also necessary. This paper discusses design, application and evaluation of swirl/vortex technologies as part of CSO and stormwater pollution control systems. 

Field R.; Brown M.P.; Vilkelis W.V. "Stormwater Pollution Abatement Technologies." Govt Reports Announcements & Index, Issue 08. Springfield, VA: NTIS, 1995.
Abstract: TD3: This publication presents information regarding best management practices (BMP's) and pollution abatement technologies that can provide treatment of urban stormwater runoff. Included in the text are a general approach which considers small storm hydrology, and watershed practices which covers public education, regulations, and source control of pollutants. Also covered are source treatment of pollutants which include vegetative BMP's and infiltration practices. Uses and modifications of installed drainage systems, types of end-of-pipe treatments including biological, chemical and physical treatments and storage and reuse of stormwater are also covered. Additionally, several tables list recommended publications should the reader wish to explore any subject matter further. 

Field R.; Pitt R.; Lalor M.; Brown M.; Vilkelis W. "Investigation of Dry-Weather Pollutant Entries into Storm-Drainage Systems." Govt Reports Announcements & Index, Issue 04. Springfield, VA: NTIS, 1995.
Abstract: TD3: The article describes the results of a series of research tasks to develop a procedure to investigate non-stormwater (dry-weather) entries into storm drainage systems. Dry-weather flows discharging from storm drainage systems can contribute significant pollutant loadings to receiving waters and although they can originate from many sources, the most significant include sanitary wastewater, industrial and commercial pollutant entries, failing septic tank systems, and vehicle maintenace activties. Protocols are discussed to: characterize the drainage area; locate and identify polluted outfalls; estimate the magnitudes of non-stormwater entries; and locate and correct the non-stormwater entries into the storm drainage system. Journal article. Pub. in Jnl. of Environmental Engineering, Paper no. 6094, v120 n5 p1044-1066 Sep/Oct 94. Prepared in cooperation with Vanderbilt Univ., Nashville, TN. Dept. of Civil and Environmental Engineering. Sponsored by Environmental Protection Agency, Cincinnati, OH. Risk Reduction Engineering Lab. 

Fuchs, S.; Haritopoulou, T.; Schaefer, M.; Wilhelmi, M. "Heavy metals in freshwater ecosystems introduced by urban rainwater runoff - monitoring of suspended solids, river sediments and biofilms." Water Science & Technology 36:8-9, 1997. 277-282.
Abstract: Sediments, suspended solids and biofilm samples at different locations of the River Alb near Karlsruhe were analysed for their heavy metal content (Pb, Cu, Cd). The main task of this study was to validate the biofilm method by comparing the measured pollution with the results of long term monitoring programs based on sediments and suspended solid samples. All compartments of the surveyed systems showed increasing heavy metal concentrations towards highly urbanised areas. The translation of data into pollution classes detected similar pollution situations for sediments and biofilms. The presented biofilm method recommends itself as a practicable instrument for assessing the heavy metal pollution in freshwater ecosystems. The easy sampling-technique, the low variability in the detected values and the ecological relevance of biofilms are the obvious advantages of this biofilm monitoring. 

Gardiner, N.E.; Cohen, J.A. "Stormwater trials and tribulations." Environmental Protection 6:5, 1995. 14-18.
Abstract: Many manufacturing, waste management, transportation, and mineral resource companies have risen to the challenge of complying with a complex set of regulations--the 1990 stormwater rules--in a competitive marketplace. But many others have struggled to meet what they call confusing, even contradictory requirements. Industrial environmental managers and regulators give widely varying assessments of the five-year-old program. Initially, facilities were given three options to comply with the stormwater rules: obtain an individual permit, join a group application, or wait for the state or regional EPA office to issue a general permit. At the time, many facilities chose the group application approach, because it offered reduced monitoring requirements and was the least expensive alternative. But certain states belatedly rejected the group approach, leaving many facilities without a viable permit long after the rules had become effective. Other facilities found that individual permits, while appropriate for certain complex facilities, included more stringent approval requirements. In the end, many facilities opted for a general permit issued by a state agency in states with delegated permit authority, or by one of EPA's 10 regional offices. The general permits offered a streamlined application process that required less data than the individual permits and were less confusing than the group permits. 

Green, M.B.; O'Connell, P.J.; Griffin, P. "Uprating and rescuing small wastewater treatment facilities by adding tertiary treatment reed beds." Water Environment Research 70:7. Alexandria, VA: Water Environment Federation, Dec 1998. 1307-1313.
Abstract: A water utility developed use of gravel-filled constructed reed beds operating in a subsurface flow mode to polish secondary effluent to meet demanding standards for 5-day biochemical oxygen demand (BOD sub(5)) and total suspended solids. Results collected by the regulatory environmental agency (EA) for 43 sites completed before the end of 1993 are given. The average BOD sub(5) concentration was 1.9 mg/L. The benefit of effluent polishing is further demonstrated by influent and effluent data from two sites that have operated since June 1990 and September 1991, respectively. Environmental agency effluent quality data are also given for 39 sites at which reed beds either treat stormwater and secondary effluent together or have been installed as remedial treatment for works struggling to meet secondary treatment standards. The average BOD sub(5) concentration for these sites was 3.0 mg/L. Remedial, or treatment plant rescue, application is illustrated by four contrasting case studies where constructed reed beds brought facilities back into compliance. 

Green, M.B.; Upton, J. "Constructed reed beds: Appropriate technology for small communities." Water Science and Technology 32:3, 1995. 339-348.
Abstract; Reed bed treatment is put in the context of a major water company's need to provide reliable, high quality, effluents from small sewage treatment works whilst seeking to minimise running costs. Design and operational information is given for reed bed applications in Severn Trent Water. Performance details are provided for application to secondary, tertiary and storm overflow treatment. The results give particular confidence in the system's ability to deliver very high quality effluents when used for tertiary treatment, the company's biggest application. Reed beds work well against less demanding criteria for secondary treatment at small sites and show great promise for storm overflow treatment. 

Gribbin, John E. Hydraulics and hydrology for stormwater management. Albany, N.Y. : Delmar Publishers, 1997. Cornell University Educational Television Center. Constructed wetlands for the management of stormwater runoff. Ithaca, N.Y.: Educational Television Center, Cornell University Media Services, 1997. 1 videocassette (106 min.).
Abstract: Reviews three constructed wetlands case studies in New York State, followed by three presentations and panel discussion with call/fax questions from the satellite broadcast downlink sites. 

Griffin, C.B. "Uncertainty analysis of BMP effectiveness for controlling nitrogen from urban nonpoint sources." Water Resources Bulletin 31:6, 1995. 1041-1050.
Abstract: The effectiveness of urban Best Management Practices (BMPs) in achieving the No-Net-Increase Policy (NNIP), a policy designed to limit nonpoint nitrogen loading to Long Island Sound (LIS), is analyzed. A unit loading model is used to simulate annual nitrogen exported from the Norwalk River watershed (Connecticut) under current and future conditions. A probabilistic uncertainty analysis is used to incorporate uncertainty in nitrogen export coefficients and BMP nitrogen removal effectiveness. The inclusion of uncertainty in BMP effectiveness and nitrogen export coefficients implies that additional BMPs, or BMPs with a greater effectiveness in nitrogen removal, will be required to achieve the NNIP. Even though including uncertainty leads to an increase in BMP implementation rates or BMP effectiveness, this type of analysis provides the decision maker with a more realistic assessment of the likelihood that implementing BMPs as a management strategy will be successful. Monte Carlo simulation results indicate that applying BMPs to new urban developments alone will not be sufficient to achieve the NNIP since BMPs are not 100 percent effective in removing the increase in nitrogen caused by urbanization. BMPs must also be applied to selected existing urban areas. BMPs with a nitrogen removal effectiveness of 40-60 percent, probably the highest level of removal that can be expected over an entire watershed, must be applied to at least 75 percent of the existing urban area to achieve the NNIP. This high rate of application is not likely to be achieved in urbanized watersheds in the LIS watershed; therefore, additional point source control will be necessary to achieve the NNIP. 

Harremoes, P.; Napstjert, L.; Rye, C.; Larsen, H.O.; Dahl, A. "Impact of rain runoff on oxygen in an urban river." Water Science and Technology 34:12, 1996. 41-48.
Abstract: The river Harrestrup is an urban river in the western region of Greater Copenhagen, Denmark. It has been subject to intensive on-line investigation of the oxygen regime in the river, both during dry weather and during rain runoff from the neighbouring urban areas. The oxygen fluctuations have been modelled both deterministicly and statisticly. The statistical features turned out to be as important as the deterministic. The final evaluation of the performance was done by comparison of extreme statistics as measured over one year with results generated by the calibrated deterministic model, superimposed with calibrated statistical properties. The result was a clear demonstration of non-compliance with oxygen standards both during dry weather and during wet weather. The technical measures are river restoration to decrease daily oxygen fluctuations and construction of detention basins in the urban catchments to decrease the impact of rain runoff. 

Hayward, K. "Storm brains." Water Quality International, 1996. 26-27.
Abstract: The climate and topography of the south-western corner of France may be just the factors that have helped Bordeaux win fame for producing wine but they have also brought problems in the form of flooding. Impetus for investment in Bordeaux's modern-day flood prevention system was provided largely by serious floods in 1982. This prompted the municipal authority, the Communaute Urbaine de Bordeaux, to authorise investment of around Fr200M ($40M) a year. Almost Fr4000M ($800M) has been spent since, much with the involvement of Lyonnaise des Eaux, which is contracted to carry out operation and much of the design and construction on behalf of CUB. 

Hicks A.L.; Larson J.S. "Impervious Surface Area and Benthic Macroinvertebrate Response as an Indicator of Impact from Urbanization of Freshwater Wetlands." Govt Reports Announcements & Index, Issue 22. Springfield, VA: NTIS, 1997.
Abstract: TD3: Urbanization is a continuing process in most societies around the world. Urban land uses produce many negative outputs in the form of sediments, excess nutrients, toxicants and pathogens. These are transported as non-point source pollution into receiving wetlands by stormwater runoff draining from the surrounding landscape. Urban land practices such as construction, extraction of groundwater, draining, filling and dredging of wetlands to make way for further development, are also sources of impact. Related stresses to wetland ecosystem are either dehydration, inundation, sedimentation, light reduction, eutrophication, contamination, thermal warming, habitat fragmentation, exotic species invasion, acidification, and salinization. The evaluation of the impact to wetlands is a difficult and expensive process for management agencies. Procedures may include laboratory analysis of water and soil samples and toxicology tests. Invertebrates are becoming increasinlgy important as a measuring tool for monitoring pollution and trophic state of fresh waters. The aquatic habitat integrates most of the parameters of the environment because it accumulates water from both air and land. The presence of certain assemblages of species of aquatic invertebrates provides valuable information on water quality, as does the absence of sensitive organisms, or high populations of tolerant organisms. The use of benthic macroinvertebrates as bioindicators of water quality is not a new technique and is widely applied in streams, rivers, and lake biomonitoring programs and research. See also PB95-227211. Sponsored by Corvallis Environmental Research Lab., OR. 

House, W.A.; Warwick, M.S. "Hysteresis of the solute concentration/discharge relationship in rivers during storms." Water Research 32:8, Aug 1998. 2279-2290.
Abstract: Hysteresis of dissolved calcium, silicon, nitrate, nitrite, ammonium and phosphorus fractions, i.e. soluble reactive phosphorus, total dissolved phosphorus and total phosphorus, in river waters during a major storm event in the R. Swale catchment in Yorkshire (U.K.), are quantified using a semi-empirical model. The model separates point and base-flow contributions of the chemical determinants from diffuse inputs. The magnitude of the diffuse inputs is related to river water discharge so that the size and rotation of the hysteresis loop is characterized by a single parameter. The approach is applied to chemical and water discharge data collected at 2 h intervals from three river sites in the catchment over a complete storm hydrograph. The results illustrate hysteresis effects for all the determinants with the majority showing "clockwise" hysteresis, i.e. higher concentrations during the rising limb of the hydrograph compared with those measured during the falling limb. The model parameters, computed by optimizing agreement between the predicted and measured concentration-discharge relationships, are generally consistent with land-use patterns in the catchment. The method has potential for further development to enable comparisons of chemical and nutrient dynamics in river catchments and the assessment of the relative importance of diffuse and point sources during high flow conditions. 

Hunter, G.L.; O'Brien, W.J.; Hulsey, R.A.; Carns, K.E.; Ehrhard, R. "Emerging disinfection technologies." Water Environment & Technology 10:6, Jun 1998. 41-46.
Abstract: As interest in ultraviolet (UV) disinfection for wastewater treatment has grown, so have the technology options. In addition to low-pressure UV systems, which have a proven track record, and medium-pressure UV systems, such technologies as broad-band pulsed xenon, narrow-band excimer, and pulsed electric fields now are being studied and tested for possible use in disinfecting wastewater, stormwater, and combined sewer overflows. 

Jones, J.; Anderson, S.; Fognani, J.; McGregor, F.R.; Axley, T. "Stormwater best management practices." Water Environment and Technology 8:10, 1996. 51-57.
Abstract: In certain circumstances, sediments that accumulate in municipal and industrial stormwater quality treatment facilities can be classified as hazardous waste under the Resource Conservation and Recovery Act (RCRA) of 1976. The affected stormwater facilities include dry detention and wet retention ponds, infiltration basins, buried concrete vaults, created wetland, stormwater inlets, grass-lined swales, and so forth. 

Karouna-Renier, N.K.; Sparling, D.W. "Toxicity of stormwater treatment pond sediments to Hyalella azteca (Amphipoda)." Bulletin of Environmental Contamination and Toxicology 58:4, Apr 1997. 550-557.
Abstract: Stormwater runoff from highways and commercial, industrial, and residential areas contains a wide spectrum of pollutants including heavy metals, petroleum hydrocarbons, pesticides, herbicides, sediment, and nutrients. Recent efforts to reduce the impacts of urbanization on natural wetlands and other receiving waters have included the construction of stormwater treatment ponds and wetlands. In addition to providing flood control, these systems improve water quality through settling, adsorption, and precipitation of pollutants. These processes remove up to 95% of metals, nutrients and sediment before they are discharged from the site. The design of stormwater ponds to provide habitat for aquatic wildlife has prompted concern over the potential exposure of aquatic organisms to these contaminants. Aquatic sediments concentrate a wide array of organic and inorganic pollutants. Although in many cases water quality criteria are not exceeded, organisms living in or near the sediments may be adversely affected. The availability of chemicals in sediments depends strongly on the prevailing chemistry. For example, toxicity of contaminants is controlled by the presence of into oxide, organic materials, and insoluble sulfides. Physical conditions of the sediment and water quality characteristics including pH, redox potential and hardness, also influence contaminant availability. The objective of this study was to evaluate the toxicity of sediments and water from stormwater ponds over a 10-d period to juvenile Hyalella azteca. Bioassay results were related to concentrations of acid volatile sulfides and metals of the tested sediments. 

Katznelson, R.; Jewell, W.T.; Anderson, S.L. "Spatial and temporal variations in toxicity in an urban-runoff treatment marsh." Environmental Toxicology and Chemistry 14:3, 1995. 471-482.
Abstract: Toxicity tests have not been widely used to asses the performance of urban-runoff treatment facilities. In the present study, Ceriodaphnia dubia toxicity tests were used to quantify toxicity of urban runoff at Crandall Creek and the downstream Demonstration Urban Stormwater Treatment (DUST) March in Fremont, California. Acute toxicity, expressed as the median time to lethality (LT50) for C. dubia, was used to compare the relative intensities of toxicity in the system. During or shortly after storm events, horizontal and vertical gradients in LT50 and electrical conductivity were observed, with high correlation between the two parameters. Toxicity diminished as time passed after the storm. The performance of the DUST Marsh as a treatment facility was evaluated for three aspects: detention, dilution, and toxicity removal. We found that toxic storm water generated by small- to medium-sized storms (5 to 25 mm rain) was contained in the marsh. Toxicity was greatly reduced upon dilution of storm water with pre-existing marsh water, and mixing of the water column increased the rate of toxicity diminution. Toxicity reduction, above and beyond that attributable to dilution, was evident in the marsh. Results of this study demonstrate the potential use of toxicity assessments as an integral component of marsh design and management. 

Kaufman, M.M. "Improving nonpoint pollution control efforts in urban watersheds." LakeLine 15:2, 1995. 22-23.
Abstract: Urban water resources planning is complicated by the frequent lack of congruence between political and watershed boundaries. One watershed may contain several counties, with numerous township and city governments. While each civil division wants control over its land use, hydrologic factors create an objective need to coordinate the management of the entire watershed. Another complication is increasing state and federal requirements for storm water control, and the accompanying decrease in federal funding available to local communities. Given the current national deficit and a pattern of reduced spending on infrastructure over the last several years, this trend is likely to continue. The lack of offering real benefits to financially strapped communities. Thus, the NPP effort should begin by demonstrating how water quality improvements can benefit many communities in real dollars. An example will demonstrate how one community has changed its planning outlook from a local to a regional perspective. 

Lee, D.H.; Bedford, K.W.; Yen, Chieh-Cheng J. "Storm and entrainment effects on tributary sediment loads." Journal of Hydraulic Engineering 120:1, 1994. 81-103.
Abstract: A two-dimensional, multiclass-size sediment transport model with source/sink terms for erosion and deposition, and a sediment bed model were developed and applied to Sandusky Bay. Ohio to study the transport of fine sand, silt, and clay through the bay for June 1 to June 30, 1981. During this period, a flood carried high sediment loads from the Sandusky River to the bay. The model's simulation showed that 79.3% of the flood's sediment loads were deposited in the upper bay. Areas of net deposition and erosion compare favorably to other published results. This study showed that the dominant sediment size transported to Lake Erie is clay, and the sediment load to Lake Erie is significantly different from that measured at the U.S. Geological Survey gage at Fremont, Ohio, located upstream of the bay. Weaknesses in state-of-the-art sediment transport modeling and field measurements are discussed. 

Lee, G.F.; Jones-Lee, A. "Implementing urban stormwater runoff quality management regulations." Water/Engineering and Management 142:4, 1995. 38-41.
Abstract: This is the second in a series of three articles on urban stormwater runoff. In the March issue of WEM, Part I discussed the need to regulate urban, industrial and, for that matter, rural stormwater runoff quality differently than the approach that was and is being used for municipal and industrial wastewater discharges. The second part focuses on some evolving concepts that recognize the need for different regulatory thinking. Also, attention is given to the regulation of chemical constituents in sediments associated with stormwater runoff. 

Lee, G.F.; Jones-Lee, A. "Issues in managing urban stormwater runoff quality." Water/Engineering and Management 142:5, 1995. 51-53.
Abstract: The aquatic plant nutrients, nitrogen (N) and phosphorus (P) compounds, are of potential concern in urban stormwater runoff due to their ability to stimulate excessive growth of aquatic plants in receiving waters. The eutrophication (fertilization) of a waterbody can be significantly detrimental to water quality-related beneficial uses. It was found in the 1970s that urban stormwater runoff contains about 100 times the total concentrations of phosphorus that are typically derived from stormwater runoff from forested areas, and about 10 times the amounts contributed from many agricultural areas. It was also found then that substantial portions of the nitrogen and phosphorus components are in particulate forms that are not available to support aquatic plant growth. 

Lee, G.F.; Jones-Lee, A. "Stormwater runoff management: The need for a different approach." Water/Engineering and Management 142:3, 1995. 36-39.
Abstract: The amended Clean Water Act, reauthorized by Congress in 1987, mandated that the U.S. Environmental Protection Agency develop a National Pollutant Discharge Elimination System (NPDES) permit program for urban stormwater runoff discharges. The initial phase of this program was to be devoted to urban areas with populations greater than 100,000. Further, industries and construction sites were required to obtain NPDES stormwater runoff discharge permits. The USEPA's current stormwater quality management program calls for stormwater-caused "pollution" to be controlled to the maximum extent practicable (MEP) through the use of best management practices (BMPs). However, this term, maximum extent practicable, has not yet been defined by Congress, the USEPA, or state or local agencies. Over the years, based primarily on hydraulic considerations, a number of structural BMPs have been developed for allegedly controlling water pollution from urban stormwater runoff. Detention basins, grassy swales and other vegetative areas and infiltration areas are often promoted as BMPs for this runoff. However, as discussed later, a critical review of the potential effects of stormwater runoff-associated chemical constituents raises significant questions about whether a detention basin is, in fact, a treatment system for removal of pollutants in urban stormwater runoff. 

Leeflang, M.; Monster, N.; Van De Ven, F. "Design graphs for stormwater infiltration facilities." Hydrological Sciences Journal 43:2. Wallingford (England): IAHS Press, Apr 1998. 173-180.
Abstract: The disconnection of sewered impervious areas is a measure to reduce the overflow frequency and hydraulic load of both combined and improved separate sewer systems. In this article the sizing of disconnection facilities is elaborated. The usual procedures for determining the required dimensions of the facilities contain some spurious assumptions. These assumptions have been removed, resulting in a more realistic design procedure for disconnection facilities to make sure that the discharge of stormwater is guaranteed. With the use of simulations various design graphs have been constructed. In the graphs the permeability of the soil (K value) is plotted against the required construction length of the facility (L value) scaled to the mount of connected impervious area. For a known K value, a known amount of impervious area and a chosen cross-section of the facility, the required construction length can be assessed directly from the graphs. The effect of a discharge drain at the bottom of a percolation trench has also been investigated. It appeared that, compared to a facility without a drain, the required dimensions of a facility with a drain decrease significantly. Consequently, soils with low permeability allow the application of percolation facilities, provided that a discharge drain is installed at the bottom of the facility. As the drain prevents groundwater filling the facility, the facility with a drain can be applied in areas with relatively high groundwater levels, as occur in many cities in the delta and polder areas of The Netherlands. 

Legret, M.; Le Marc, C.; Demare, D.; Colandini, V. "Heavy metals pollution in a detention pond receiving highway run-off." Environmental Technology 16:11, 1995. 1049-1060.
Abstract: Heavy metals accumulation in sediments from detention pond receiving highway run-off of the Chevire bridge, close to Nantes (Loire-Atlantique), has been studied. Pb, Cu, Cd and Zn contamination of the sediment and of the top layer of the soil was shown, high concentrations were observed until the 10-20 cm layer. The risk of heavy metals release was evaluated using a sequential extraction scheme. Metals are mainly extracted by acetic acid and hydroxylamine hydrochloride. The pH and redox potential variations could be the controlling factors of metal mobility. The best management practices of this work would be the regular cleaning of the sewers and of the pond as also the disposal in landfill or the treatment of sediments. 

Line, D.E.; Arnold, J.A.; Jennings, G.D.; Wu, Jy "Water quality of stormwater runoff from ten industrial sites." Water Resources Bulletin 32:4, 1996. 807-816.
Abstract: This study was to designed to determine concentrations of selected metals, organic compounds, pesticides, and conventional pollutants in stormwater runoff from two North Carolina businesses in each of the following five general industrial groups: auto salvage, metal fabrication, scrap and recycling, vehicle maintenance, and wood preserving facilities. The sampling procedure involved collecting a first flush sample of runoff from a single storm event and both first flush and composite samples of runoff from three consecutive storm events. Analysis of samples collected during the first flush indicated that zinc and copper were the most common of the 13 metals included in the analysis. Additional analysis documented that several volatile organic, semi-volatile organic, or pesticide compounds including acrolein, methylene chloride, xylenes, toluene, tetrachloroethylene, trichloroethylene, pentachlorophenol, and aldrin were also found in the first flush samples. Concentrations of aggregate organics, nitrogen, phosphorus, and sediment were determined in both first flush and three-hour composite samples. Concentrations of pollutants in first flush samples were similar to those in corresponding composite samples. 

Line, D.E.; Osmond, D.L.; Gannon, R.W.; Coffey, S.W.; Jennings, G.D.; Gale, J.A.; Spooner, J. "Nonpoint sources." Water Environment Research 68:4, 1996. 720-732.
Abstract: Nonpoint source (NPS) pollution originates from diffuse land areas that intermittently contribute pollutants to surface and ground water. This article is a review of 1995 literature on several aspects of NPS pollution, including policy, economics, and management issues; effects and extent of pollutants in surface and ground water; pollution controls; and modeling and monitoring. Several publications addressed the broad topic of nonpoint sources. Novotny and Olem (1994) discussed prevention, identification, and management issues related to the control of NPS pollution, including laws, regulations, and policies; hydrologic considerations; atmospheric deposition; erosion and sedimentation; urban pollution; toxic pollution; modeling and monitoring; agricultural issues; wetlands; management and restoration; and integrated planning and control of NPS pollution on a watershed basis. A book examining nitrogen fertilization, fixation, and loss and the environmental implications of alternative nitrogen sources on ecosystems was published (Bacon, 1995). Herricks and Jenkins (1995) edited a book on assessing, controlling, and improving the quality of stormwater runoff from industrial and municipal areas. Proceedings of a conference on surface water quality and ecology (Water Environment Federation, 1995) focused on a wide range of topics, including the Everglades, sediment impacts on water quality, marine and estuarine systems, watershed management, water quality criteria and standards, environmental modeling and monitoring, natural systems, stormwater impacts, and risk assessment. Proceedings of a conference on animal waste management provided an interdisciplinary discussion of animal waste and its interactions with soil and water within a watershed framework (Steele, 1995). The National Agricultural Library published bibliographies on dairy farm manure management (Makuch, 1995a) and NPS pollution issues (Makuch, 1995b). 

Licsko, Z.J.; Struger, J. "Trace metals contamination of urban streams and stormwater detention ponds." In W. James, ed., Advances in modeling the management of stormwater impacts. Chelsea, MI: Ann Arbor Press, 1996. 269-277.
Abstract: In 1991, trace metal levels were monitored over a nine month period in two urban creeks in the Hamilton Harbour watershed and in two urban stormwater detention ponds in Guelph, Ontario. Samples were collected both during dry or non-event periods and immediately after wet weather events. Both water and surficial sediment samples were tested for cadmium, copper, lead, mercury, nickel and zinc. In almost all cases wet weather concentrations of lead, copper and zinc in the water collected from the two urban streams exceeded the Canadian Water Quality Guidelines (CWQGs) for the protection of freshwater aquatic life. While not designed for water quality improvement, both stormwater ponds reduced the levels of metals in discharged water, but in the process trace metals accumulated in sediment to levels above the lowest effect level guideline for the protection and management of aquatic sediment in Ontario, and in the case of zinc above the severe effect level guideline. Although these levels are above guidelines, further investigation is needed to establish a relationship between metal contamination and biological impacts. This is particularly important for ponds intended for the dual purposes of stormwater treatment and as habitat for biota. 

Loganathan, G.V.; Watkins, E.W.; Kibler, D.F. "Sizing storm-water detention basins for pollutant removal." Journal of Environmental Engineering 120:6. New York: ASCE, 1994. 1380-1399.
Abstract: A statistical formulation for estimating the average time of detention within a pond for a captured runoff volume is presented. For a conservative estimator, it is assumed that mixing takes place during an event and that settling occurs over a period to empty the captured volume or the time between successive events, whichever is smaller. This analytically determined detention time is used in conjunction with a pollutant-settling efficiency-detention time curve to estimate the settling efficiency. This curve is generated from Stormwater Management Model (SWMM) program simulations and shown to be independent of runoff statistics, pond configuration, and arbitrary but constant influent concentration under complete mixing. The analytical detention time estimate, in combination with the settling efficiency curve provides a valuable desk top method for the planning-level design of detention basins for pollutant removal. The method performs quite well compared to the results obtained from long-term SWMM simulation runs. 

Macpherson, J. "A Review of Current Stormwater Treatment Technologies." Land and Water 42:3, Jun 1998. 40-42.
Abstract: Many port facilities, like other industrial operations, are confronted with environmental regulations governing the quality of stormwater collected and discharged. Contaminants such as oil and grease, sediment, copper, lead and zinc have been accepted for years as unavoidable by-products of industrial activities. Stormwater can mobilize these materials and carry them into nearby receiving waters, causing water pollution and sediment contamination. While the problem is easy to identify, it has proven difficult to solve with existing technology. New products and methods, however, show promise in providing cost-effective ways to reduce or eliminate contaminants in stormwater. This article examines several technologies recently developed or modified to apply to stormwater treatment. 

Makepeace, D.K.; Smith, D.W.; Stanley, S.J. "Urban stormwater quality: Summary of contaminant data." Critical Reviews in Environmental Science and Technology 25:2, 1995. 93-139.
Abstract: Storm water quality can have a significant impact on receiving water bodies. Two of the major impacts can be to aquatic life in the receiving water body and downstream water users that might use the water as a raw water source for drinking water. With increased understanding of the importance of drinking water quality to public health and the recognition that protecting raw water sources is an integral component of the water treatment process, there is a greater need to identify possible contaminants found in storm water that impact the receiving water quality. Presented is a literature review to identify and quantify contaminant data available on storm water. The article focuses on work that presented specific chemical, physical, and biological parameters rather than the traditionally used overall water quality parameters, such as biochemical oxygen demand and total suspended solids. To assess impacts and to put into perspective the importance of the reported concentrations, values were compared with pertinent guidelines, regulations, and levels that have been reported to cause possible adverse impacts. 

Maltby, L.; Boxall, A.B.A.; Forrow, D.M.; Calow, P.; Betton, C.I. "The effects of motorway runoff on freshwater ecosystems: 2. Identifying major toxicants." Environmental Toxicology and Chemistry 14:6, 1995. 1093-1101.
Abstract: Previous studies have provided prima facie evidence that runoff from the M1 motorway, UK, affects both the quality of the receiving water and the biota living there, in sites short distances from point sources-i.e., possible worst-case situations. Because discharges contain a wide variety of contaminants, both the identification of toxicants and the establishment of causal relationships between observed changes in water/sediment quality and biology are often difficult. In this particular case, the problem was addressed by conducting a series of toxicity tests using the benthic amphipod Gammarus pulex. The abundance of this species was greatly reduced downstream of the point where motorway runoff entered the stream. Stream water contaminated with motorway runoff was not toxic to G. pulex. However, exposure to contaminated sediments resulted in a slight reduction in survival over 14 d, and sediment manipulation experiments identified hydrocarbons, copper, and zinc as potential toxicants. Spiking experiments confirmed the importance of hydrocarbons, and fractionation studies indicated that most of the observed toxicity was due to the fraction containing polycyclic aromatic hydrocarbons. Animals exposed to contaminated sediments and water spiked with sediment extract accumulated aromatic hydrocarbons in direct proportion to exposure concentrations. 

Marsalek, J.; Watt, W.E.; Anderson, B.C.; Jaskot, C. "Physical and chemical characteristics of sediments from a stormwater management pond." Water Quality Research Journal of Canada 32:1, 1997. 89-100.
Abstract: Physical and chemical properties of bottom sediment and suspended particulates were studied at the Kingston stormwater pond. The bottom sediments have accumulated in the pond at an average rate of 0.02 m/year and comprised gravel, sand, silt and clay; the first two materials accumulated only by the inlet and the last two were spread throughout the pond and represented up to 45% and 54% of the total sediment, respectively. The water content of the accumulated sediment ranged from the low of 48%(by the inlet) to the high of 78%(at the outlet), by volume. The assessment of total metals in the pond sediment against the MOEE sediment quality guidelines indicated a gross pollution by Cr, and a marginal-to-significant pollution by Cd, Cu, Fe, Pb, Mn, Ni and Zn. Sequential analysis of sediment samples indicated that 40-90% of the retained metals were in potentially mobile forms. The chemistry of suspended particulates, representing silt and clay, was similar to that of the bottom sediment, except in the case of Cr. 

Mason, R.P.; Sullivan, K.A. "Mercury and methylmercury transport through an urban watershed." Water Research 32:2, Feb 1998. 321-330.
Abstract: Samples for mercury (Hg) and methylmercury (MMHg) were collected during both base flow and storm flow over the period of a year in the two branches of the Anacostia River, an urban, impacted river within greater Washington, D.C. The concentrations in each branch were correlated for comparable samples suggesting that similar processes are contributing Hg and MMHg to each branch. Concentrations of total Hg during base flow were less than 10 ng/l but were 3-5 times higher during storm flow, mainly as a result of the high particulate loading (up to 800 mg/l). Storm flows are therefore the major vector for Hg transport in this river. Total Hg concentrations generally increased as SPM and POC increased. However, the K sub(d) decreased with increasing SPM for both Hg and MMHg, and the magnitude of the K sub(d) was a function of the %POC, suggesting that the strength of particulate binding was a function of the organic content of the particles. Reactive Hg was a small fraction of the total and there was little relationship between dissolved Hg and DOC. Equilibrium calculations suggest that all the dissolved Hg is bound to DOC even at the lowest DOC concentrations encountered, Watershed yield calculations suggest that the flux from these rivers is a relatively large fraction of the atmospheric input, in contrast to what has been found in other systems. 

Mayer, T.; Marsalek, J.; Delos Reyes, E. "Nutrients and metal contaminants status of urban stormwater ponds." Lake and Reservoir Management 12:3, Oct 1996. 348-363.
Abstract: Stormwater detention ponds are one of the management options designed to reduce pollution of the receiving water bodies by urban runoff. Many such structures are operated in the Greater Toronto Area. A seasonal survey of four stormwater detention ponds was conducted to estimate the inventories of heavy metals and phosphorus in bottom and suspended sediments. The concentrations of heavy metals in suspended and bottom sediments suggest that land use has the most profound impact on the quality of suspended and deposited sediments, with the pond in an industrial/commercial catchment having the highest metals concentrations, followed by ponds located in the residential catchments. The suspended and bottom sediments data suggest that the removal of heavy metals in these reservoirs may not be adequate. Apart from land use, the magnitude of runoff and seasonal conditions impacted the sediment and water quality in these ponds. The deleterious effects of restricted water circulation during the dry summer conditions and under the winter ice cover are apparent from the elevated levels of ammonia-N, sometimes reaching or exceeding the levels recommended by the Canadian Water Quality Guidelines (CCREM 1987) for the protection of aquatic life. 

Mikkelsen, P.S.; Jacobsen, P.; Fujita, S. "Infiltration practice for control of urban stormwater." Journal of Hydraulic Research/Journal de Recherches Hydraulique 34:6, 1996. 827-840.
Abstract: Infiltrating stormwater locally into the ground instead of discharging to conventional pipe sewers is increasingly considered as a means of controlling urban stormwater runoff. This paper reviews the most recent developments within this field and points out some of the major problems remaining. Easy-to-use methods for designing stormwater infiltration structures are available but methodologies for determining the design parameters based on local conditions and technologies for clogging prevention are needed. No evidence so far points at a high risk of groundwater contamination but the quality of surface soils will decrease due to long-term infiltration of polluted stormwater runoff. Simplistic modelling approaches based on conceptual process descriptions are needed for assessing the impact on soil and groundwater in local areas. The perspectives in relation to control of stormwater runoff are clear; the runoff peaks and volumes are decreased, and the urban hydrological cycle is returned to a more natural state. In some aspects stormwater infiltration is more effective for runoff reduction and abatement of pollution discharges than detention basins. In the future, measures to promote urban stormwater infiltration need to be developed. 

Moore, R.; Freedman, P. "Nonpoint sources." Water Environment and Technology, 7:9, 1995. 47.
Abstract: Great and measurable improvements to water quality have been achieved since the early 1970s by controlling the discharges of point sources, both municipal and industrial. Today the challenge is controlling nonpoint sources from almost every kind of land use. Recent estimates by EPA indicate that nonpoint sources are the leading cause of surface water quality impairment nationwide. Defining the problems and developing cost-effective solutions is difficult. 

Mulliss, R.; Revitt, D.M.; Shutes, R.B.E. "The impacts of discharges from two combined sewer overflows on the water quality of an urban watercourse." Water Science & Technology 36:8-9, 1997. 195-199.
Abstract: The impacts of combined sewer overflows and surface water outfalls on receiving water quality are assessed by comparing dry weather flow and storm event concentrations of dissolved oxygen, BOD, total and unionised ammonia, pH, dissolved copper and total zinc with those recommended by the River Ecosystem classification guidelines for freshwaters in the UK. The deteriorating conditions during wet weather are identified by water quality falling below the RE2 category for all monitored pollutants, other than dissolved copper, and reaching the most grossly polluted condition for BOD and total ammonia. 

Mulliss, R.M.; Revitt, D.M.; Shutes, R.B. "The impacts of urban discharges on the hydrology and water quality of an urban watercourse." Science of the Total Environment vol. 189-190, Oct 1996. 385-390.
Abstract: This paper presents the findings of a study which has investigated the effects of urban discharges upon the hydrology and water quality of a small urban watercourse located in north London. A variety of hydrological variables and water quality parameters were monitored at a site downstream of two surface water outfalls (SWOs) and two combined sewer overflows (CSOs). Precipitation volume was found to be highly correlated with the total storm discharge (r super(2) = 0.91) and the duration of storm flow (r super(2) = 0.93). Precipitation intensity displayed a 0.67 level of correlation with peak discharge volume. Aqueous loadings of biochemical oxygen demand (BOD), nitrate, chloride, total ammonia, suspended solids and total and dissolved zinc, copper, cadmium and lead, increased during the five monitored storm events. The highest increases in pollutant loadings compared with dry weather values were associated with BOD and suspended solids. 

Muscara, J.P.; Cleveland, T.G.; Wang, K.H. Field Evaluation of Selected Highway Construction Temporary Sediment Controls for Storm Water Pollution Prevention Plans. Springfield, VA: NTIS, 1997.
Abstract: A highway construction project in Houston was monitored from pre-construction through the first phase of construction to determine the effectiveness of temporary sediment controls for pollutant control. Nearby receiving waters were also monitored to determine the type and quantity of pollutants that left the site. Nutrients, metals, and general water quality parameters were monitored throughout the investigation period. The receiving-water bodies showed little or no changes in water quality parameters. There was no consistent, quantifiable effect of the use of the temporary sediment controls as pollutant controls as installed at the study site. 

National Water Resources Institute of Canada, Center for Inland Waters. "Nutrients and metal contaminants status of urban stormwater ponds." Lake and Reservoir Management 11:2, 1995. 167.
Abstract: Almost 50% of the earth's population live in urban areas and this proportion increases rapidly. Urbanization has a profound impact on freshwater ecosystem, as urban sources are an important component of the non-point source pollution. Stormwater detention ponds have increasingly been used to mitigate the impact of urban pollution on receiving water bodies. Several such structures are in operation in the Greater Toronto Area (GTA). A seasonal survey of four stormwater detention ponds from the Greater Toronto Area was conducted to estimate the inventories of heavy metals and phosphorus in bottom and suspended sediments and to assess their effectiveness. As the chemical composition of runoff is effected by the land use, the selection of the ponds had to consider various urban settings. The results show that the land use has the most profound impact on the quality of transported and deposited sediment, with the reservoir from industrial/commercial catchment having the highest heavy metals concentrations, followed by reservoirs located in the residential catchment. The data suggest that the removal of heavy metals in these reservoirs may not be adequate. Apart from the land use, magnitude of runoff and seasonal conditions impacted the sediment and water quality in the ponds. The deleterious effects of restricted water circulation during the dry summer conditions and under the winter ice cover are apparent from the elevated levels of ammonia-N, sometimes exceeding the threshold levels of 300 mu g/L. 

Nix, P.G.; Stecko, J.P.; Hamilton, S.H. "A constructed wetland for the treatment of stormwater contaminated with diesel fuel." ARCTIC AND MARINE OIL SPILL PROGRAM TECHNICAL SEMINAR. OTTAWA, ON: ENVIRONMENT CANADA, 1994, vol. 1. 439-464.
Abstract: The treatment performance of a constructed wetlands was monitored during the summer to assess its ability to treat stormwater runoff contaminated with diesel fuel. Kinetic data (i.e., microbial mineralization) suggested a minimum degradation rate of 6.9 mgC/m super(2)/h or 6.4gC/h for the entire wetland. In contrast, empirical data (which included biological, chemical and physical removal processes) for inflow and outflow hydrocarbon concentrations indicated that removal rates were as high as 1,605 gC/h. As a result of these latter data, the hydraulic retention time required to reduce influent concentrations from 100 mg/L to less than 5 mg/L (the criterion value for the protection of aquatic life) in the effluent was only 15 h. As a part of the design criteria, an initial primary treatment section was included to remove and/or retain sudden high loadings of hydrocarbons (i.e., spills or first flush stormwater events) through chemical/physical processes such as sedimentation and volatilization. Processes of microbial mineralization, inhibited in this initial section by high diesel fuel concentrations, then acted as a self-sustaining long-term treatment process in subsequent downstream sections. 

Nnadi, F.N.; Ashe, K.W.; Sharek, R.C. Design and Performance of Dry Detention Ponds with Underdrain Systems. Orlando: University of Central Florida Dept. of Civil and Environmental Engineering, 1997.
Abstract: The management of highway stormwater runoff has become an environmental concern due to its ability to contaminate natural water bodies that receive the runoff. The Florida Department of Transportation (FDOT) uses the dry detention ponds with underdrain systems to enhance the highway stormwater quality before it is discharged to the receiving water bodies. Because there is need for FDOT to have a clear understanding of the present condition of all existing dry ponds under its jurisdiction, this study concentrated on the inventory of the dry detention ponds with underdrains in the state. Three of the identified non-functioning and two of the functioning ponds were investigated for seven months to identify the potential factors that affect their performance. During the investigation, the ponds were evaluated using laboratory, field and forensic approaches. A soil investigative study was conducted to identify the possibility of silting and accumulation of organic materials from the runoff and the possible presence of clayey soil within and around the pond area. It also included evaluation of soil classification, infiltration rates and the depth of underdrains in relation to the design criteria. The condition of the filter materials was also investigated to see if clogging was a factor. The groundwater and structural elevations in and around the ponds system were evaluated and compared to the design values. 

Novotny, V.; Witte, J.W. "Ascertaining aquatic ecological risks of urban stormwater discharges." Water Research 31:10, Oct 1997. 2573-2585.
Abstract: Stormwater discharges are intermittent inputs into receiving waters. In overall, the wet-weather flow periods in the receiving waters resulting from stormwater flows may represent only a fraction of the annual flow. In most humid regions the probability of wet weather overflow from urban storm sewers is between 4 and 8% and is less for combined sewer overflows. A methodology which enables one, using probabilistic principles, to calculate risk of wet-weather discharges to aquatic ecology (aquatic life) is presented. Risk is a joint probability that a genus will be acutely affected by the concentration. It is a dimensionless, additive number, i.e. risks by several pollutants can be added together to approximate the synergic effects. It can be used for ranking pollutants in wet-weather discharges as well for ranking the discharges themselves. A reciprocal of the risk is the recurrence interval between the occurrences of such damages. The methodology was documented by calculating risks of four metals in an urban stream. 

Pegram, G.G.S.; Goergens, A.H.M.; Stoffberg, F.A.; Du Preez, P. "Stochastic reservoir system analysis and manufactured hydrology - a new perspective." Journal of the South African Institution of Civil Engineering 39:2, 1997. 17-25.
Abstract: The Algoa Water Resources System was analyzed in 1983 and again in 1994 after a severe drought, the consequence being that the historical firm yield from the system dropped by an alarming 20 per cent. The hydrologies, both measured and manufactured (extended and patched), were put under scrutiny and with the assistance of deterministic and statistical arguments were found to be consistent. The main culprit for the apparently anomalous severe drought was an uncharacteristically low rainfall period, which, combined with an exceptional non-linearity in the rainfall-runoff relationship, spawned unusually severe critical sequences of stream-flow. The paper describes the methods adopted to achieve the diagnosis. 

Pillard, D.A. "Assessment of benthic macroinvertebrate and fish communities in a stream receiving storm water runoff from a large airport." Journal of freshwater ecology 11:1, 1996. 51-59.
Abstract: Prior to the opening of Denver International Airport, Stapleton International Airport (SIA) was the major airport in Colorado. Typically, storm water runoff from SIA was collected and directed to a water treatment facility. However, during winter months when deicers were being used, heavy snows or rains periodically taxed the capacity of the storm water collection system and untreated water was diverted directly into Sand Creek. A study was conducted to determine if the benthic macroinvertebrate and fish communities in the creek has been permanently influenced. Samples for chemical and biological analysis were collected at sites upstream and downstream of the airport outfalls. No ethylene or propylene glycol was found in the creek. Benthic macroinvertebrate communities were dominated by pollution-tolerant organisms, with chironomids being the most abundant group. Benthic macroinvertebrate density and diversity downstream of the storm-water outfalls were not significantly different from those at the upstream sites. The most abundant species of fish collected in Sand Creek were creek chub (Semotilus atromaculatus), white sucker (Catostomus commersoni), and fathead minnow (Pimephales promelas). These species dominated the catch at all sites. Fish were most dense downstream of the storm water outfalls; no evidence of stream degradation due to SIA could be found. Sand Creek is an urban stream, historically impacted by chemical and physical perturbations. Fish and benthic macroinvertebrate abundance and diversity in Sand Creek are most likely dictated by available habitat and pre-airport water quality. 

Pisano, W.C. "Pollutant control for stormwater events." Water Environment & Technology 10:1, Jan 1998. 41-43.
Abstract: In California and other western states, rainfall can be erratic, falling for only 2 to 3 months in late fall and averaging about 0.635 mm/hr (0.025 in./hr). Time between rainfall events in the Southwest averages about 200 hours; in the Eastern Seaboard that same period is about 80 hours. Because pollutant loads carried by these rains can be significant, environmentalists and others are constantly seeking best management practices (BMPs), such as increased street or catchbasin cleaning, to overcome and mitigate associated problems. Not all sanitary connections can be practically detected and eliminated from old storm systems and, no matter what source control education efforts are made, people will continue to dump animal waste and automobile oil into catchbasins. Because many cities still have combined sewer systems, these pollutants will continue to be a problem. 

Pitt, R.; Field, R.; Lalor, M.; Brown, M. "Urban stormwater toxic pollutants: Assessment, sources, and treatability." Water Environment Research 67:3, 1995. 260-275.
Abstract: This paper summarizes an investigation to characterize and treat selected stormwater contaminants that are listed as toxic pollutants (termed toxicants in this paper) in the Clean Water Act, Section 307. The first project phase investigated typical toxicant concentrations in stormwater, the origins of these toxicants, and storm and land-use factors that influenced these toxicant concentrations. Of the 87 stormwater source area samples analyzed, 9% were considered extremely toxic (using the Microtox registered toxicity-screening procedure). Moderate toxicity was exhibited in 32% of the samples, whereas 59% of the samples had no evidence of toxicity. Only a small fraction of the organic toxicants analyzed were frequently detected, with 1,3-dichlorobenzene and fluoranthene the most commonly detected organics investigated (present in 23% of the samples). Vehicle service and parking area runoff samples had many of the highest observed concentrations of organic toxicants. All metallic toxicants analyzed were commonly found in all samples analyzed. The second project phase investigated the control of stormwater toxicants using a variety of bench-scale conventional treatment processes. Toxicity changes were monitored using the Microtox registered bioassay test. The most beneficial treatment tests included settling for at least 24 hours (up to 90% reductions), screening and filtering through at least 40- mu m screens (up to 70% reductions), and aeration and/or photodegradation for at least 24 hours (up to 80% reductions). Because many samples exhibited uneven toxicity reductions for the different treatment tests, a treatment train approach was selected for the current project phase. This current phase includes testing of a prototype treatment device that would be useful for controlling runoff from critical source areas (e.g., automobile service facilities). 

Pratt, C.J. "Research and development in methods of soakaway design." Journal of the Institute for Water and Environmental Management 10:1. London: The Institution, Feb 1996. 47-51.
ABSTRACT: Soakaways have been a traditional method of disposal of stormwater for decades, and their usage has mainly been determined by the absence of a convenient watercourse, drain, or sewer into which to discharge runoff arising from roofs and paved surfaces. Today, soakaways are still being installed at a rate of tens of thousands per annum, despite the extensive storm-sewer systems in the UK. It is therefore surprising that little systematic research and development has been undertaken into their design and performance, or into the appropriate forms of maintenance to be conducted to extend operational life. The paper briefly describes the recent research into, and design approaches for, the sizing of soakaways. An example is given of the use of Building Research Establishment Digest 365 to review alternative soakaway designs and to assess the cost implications. Some field data are reported which (a) illustrate the seasonal variability and difficulties of determination of the soil infiltration rate, and (b) provide some insight into the pollution issues from the use of soakaways. 

Pratt, C.J. "A review of source control of urban stormwater runoff." J INST WATER ENVIRON MANAGE, 9:2, 1995. 132-139.
Abstract: Stormwater management, based upon techniques located at or close to where rain falls, is reviewed and two categories (at the ground surface and below-ground) are illustrated. The management of storm-water by these source control techniques requires both quantity and quality design criteria to be employed, and for maintenance provision to be clearly in-built. Source control techniques have been studied in projects since the 1980s, and it is suggested that the present emphasis upon sustainable development should encourage their incorporation within environmental/catchment management strategies to assist in addressing a number of identified problems from the uncontrolled discharges of stormwater. 

Pratt, C.J.; Mantle, J.D.G.; Schofield, P.A. "UK research into the performance of permeable pavement, reservoir structures in controlling stormwater discharge quantity and quality." Water Science and Technology 32:1, 1995. 63-69.
Abstract: The paper reports on a field study on a permeable, reservoir pavement constructed in 1986 at Nottingham, UK; surfaced with permeable, concrete block paving; and with a different sub-base stone-type in each of four reservoirs, from which the discharges were monitored for quantity and water quality. Hydrological relationships involving rainfall, outflow duration and antecedent conditions are presented. Water quality parameters are shown to be stable in value after some six months, by which time surface contaminants on the sub-base stone had been washed out of the construction. As outflow volume is reduced and water quality parameters (SS and Pb) are low in value, pollutant outflow loadings are significantly lower than with traditional, impermeable surfaces. 

Qian, S.S. "Rejoinder." Environmental and Ecological Statistics 4:1, Mar 1997. 28-29.
Abstract: I appreciate the comments of Dr Myers very much. I have only three brief remarks to make in this rejoinder. First, the data used in the paper is the total phosphorus content in the top 20 cm of the soil, which represents the accumulation in the past 60 or so years. (The annual soil buildup in WCA2A is slightly over 0.3 cm.) Because phosphorus does not have a gaseous phase, it cannot be released into the atmosphere and can only be stored in the soil or remain in the water. For the purpose of this study, that is to study the effects of agricultural runoff from the Everglades Agricultural Area (EAA) which has been in existence for about 50 years, the data represent the effect of the entire EAA history. If the water column phosphorus concentration were used, the data would represent a snapshot in time. Second, the proposed constructed wetlands are expected to be similar to WCA2A in terms of ecological functions, but with better engineering control of water distribution. However, the question under debate is how large the constructed wetlands should be in order to reduce the phosphorus concentration in agricultural runoff to background level. Since the effluent water column phosphorus concentration from WCA2A is the same as the background level, the affected area of WCA2A indicates what the size of the proposed constructed wetlands should be. This is why only the affected area is of interest. The conditional mean concentration of phosphorus would indeed be of interest, especially in studies of how ecosystems respond to elevated nutrient levels. For example, there are two mono-culture zones where respectively, cattail and sawgrass are the dominant species, and a mixed cattail and sawgrass zone in WCA2A. 

Reinelt, L.E.; Horner, R.R. "Pollutant removal from stormwater runoff by palustrine wetlands based on comprehensive budgets." Ecological Engineering 4:2, 1995. 77-97. 
Abstract: Comprehensive budgets of total suspended solids (TSS), total phosphorus (TP), total zinc (the most prevalent metal in urban runoff), and fecal coliforms (FC) were developed for two palustrine freshwater wetlands in Washington, USA. These budgets were based on input (inflow, precipitation, groundwater) and output (outflow, evaporation). One wetland received runoff from a primarily urbanized watershed (187 ha), whereas the other watershed (87 ha) was mostly rural and forested. Annual loadings to the urban wetland for TSS, TP, and zinc were 107, 0.63 and 0.43 kg/ha/yr, respectively, based on watershed area. Corresponding loadings to the nonurban wetland were 30, 0.62 and 0.08 kg ha super(-1) yr super(-1). High TP input from groundwater at the nonurban wetland (82% of the TP input) resulted in overall loadings comparable to the urban wetland. Fecal coliform loadings were 4.2/10 super(10) and 1.4/10 super(9) organisms/ha/yr for the urban and nonurban wetlands, respectively. Mean annual removal percentages (over the two-year study period) for TSS, TP, zinc, and FC were estimated at 14, 8, 31, and 49%, respectively in the urban wetland (2 ha). Corresponding removal rates in the nonurban wetland (1.5 ha) were 56, 82, 23, and 29%, respectively. Pollutant removal was influenced by season, flow conditions, residence time, pollutant source (surface versus groundwater), and pollutant state (solid versus dissolved). Results for the nonurban wetland showed that groundwater inputs were significant for TP loadings and removal. 

Ritter, W.F.; Dworsky, B.L.; Kauffman, G.J.; Mills, D. "Planning for urbanization: How far in the future." INT WATER RES ENG CONF PROC, ASCE, RESTON, VA, (USA), 1998 vol. 2. Reston, VA: ASCE, 1998. 979-984.
Abstract: Urban drainage systems installed during early development caused localized flood which led to detention basins becoming a standard feature in urban areas. In the 1990's with the regulation of both stormwater quality and quantity, comprehensive stormwater management began. For planning drainage facilities, peak rate of runoff, volume of runoff and time distribution of runoff are important. There are a large number of methods available to estimate peak runoff rates, but today many stormwater ordinances are specifying what methods must be used. Stormwater management construction cost have increased 30% over the past decade. Approximately two-thirds of construction costs are spent to control stormwater quantity and one-third on stormwater quality. 

Robbins, R.; Dodds, R.; Binkley, S. "Water Reuse." Industrial Wastewater 6:5. Little Rock, AK: Associates Ltd., Oct 1998. 32-35.
Abstract: Regulatory and engineering improvements keep stormwater runoff from discharging high levels of BOD, COD, and suspended solids into a high-quality receiving stream. 

Rochfort, Q.J.; Anderson, B.C.; Crowder, A.A.; Marsalek, J.; Watt, W.E. "Field-scale studies of subsurface flow constructed wetlands for stormwater quality enhancement." Water Quality Research Journal of Canada 32:1, 1997. 101-117.
Abstract: Two subsurface flow constructed wetlands were tested for pollutant removal performance in conjunction with an on-line stormwater detention pond, in Kingston Township, Ontario. The 4.9 m super(2) wetland cells were filled with 9 mm limestone gravel, and planted with cattail, common reed and spike rush. Changes in nutrient(total organic carbon, PO sub(4) super(3-) and NH sub(4+)), suspended solids and metal (Cu, PB, Zn) concentrations were used to assess performance. Contaminant removal occurred through a combination of physical, chemical and biological means. As with any biological system, variation in performance of stormwater wetlands can be expected to occur as a result of fluctuations in contaminant loading, contact time and ambient environmental conditions. Three methods of sizing stormwater wetlands (impervious surface area, volumetric load and kinetic reaction rates) were compared using the same design storm and data from this study. From this comparison it was seen that the kinetic sizing approach proved to be the most versatile, and allowed for adaptation to northern climatic conditions and anticipated nutrient loading. 

Roesner, L.A.; Rowney, A.C. "National storm water quality regulations and standards." Journal of Hydraulic Research/Journal de Recherches Hydraulique 34:6, 1996. 841-856.
Abstract: This paper reviews the storm water quality regulations of six major industrialized nations: The United States, Canada, United Kingdom, Germany, Australia and Japan, the order being set by the principal authors (both North America) who consider this to be a logical geographical order. The main purpose of the paper is simply to introduce the interested reader to these rules as a matter of broadening his/her knowledge base. Due to space limitations much detail is left out, but hopefully the essence of the laws and regulations are presented. No attempt has been made to compare and contrast these different rules with the objective of determining which are the best rules or what the "best rule" might be. The reader will observe that the differences are great, and to a large degree reflect the culture of the individual country. 

Ruban, G. "Continuous measurement of pollution due to urban effluents under wet conditions using optical systems." Water Science and Technology 32:1, 1995. 241-247.
Abstract: Optical sensors appear well adapted to the pollution measurement of urban discharges during wet weather: they allow a continuous and long time investigation of sudden and highly variable phenomena such as rainfall events. They may also be connected to remote monitoring and sanitary equipment automation systems. This paper deals with the measurement principles and use of this type of equipment: adjustment and calibration, sample collection, equipment maintenance and measurement validation. Taking into account the hydraulicity (flow rate or velocity) allows one to improve appreciably the calibration for runoff waters. Calibration at the laboratory seems better than calibration using registered data on the field, as it makes it possible to eliminate the Suspended Matter under-estimation resulting from sampling/analysis. 

Safavi, H.R. "Quality control of urban runoff and sound management." Hydrobiologia, 320:1-3, 1996. 131-141.
Abstract: Urban runoff pollution sources, including storm water, combined sewer overflows, and diffuse or nonpoint sources of water pollution, are formidable obstacles to achieving water resource goals in many municipalities. Because of limitations of water resources in arid and semiarid climates, pollution prevention of water resources with polluted runoff water has great importance in water resources management. This paper provides an overview of urban runoff pollution issues including types of pollutants, their origins and modes of transport, and their effects on receiving waters. To identify type and amount of existing pollution in runoff water, Isfahan has been chosen as a case study and sampling from eleven selected sampling stations at different points during one year have been taken and the results discussed. Because in some cases the quality of runoff water was even worse than domestic wastewater, sound collection, transport and reuse was also mentioned. Urban runoff pollution problems are more difficult to control than steady-state, dry-weather point discharges because of the intermittent nature of rainfall and runoff, the large variety of pollutant source types, and the variable nature of source loadings. Since the expense of constructing facilities to collect and treat urban runoff is often prohibitive, the emphasis of storm water pollution control should be on developing a least-cost-approach, including nonstructural controls and low-cost structural controls. Some runoff management methods are discussed. 

Sansalone J.J.; Buchberger S.G. "Effective Control Strategies for Highway Nonpoint Pollution." Govt Reports Announcements & Index, Issue 03. Springfield, VA: NTIS, 1999.
Abstract: TD3: The goals of this research were the characterization of lateral pavement sheet flow and based on characterization results, development of passive in-situ treatment for metal elements and solids transported in storm water drainage. Characterization results were obtained from a highway experimental site which intercepted lateral pavement sheet flow directly from inter State Route 75 (I-75) in Cincinnati, Ohio. Measurements at the site included rainfall, flow and water quality parameters for 12 storm events over 3 years. Laboratory analysis included metal element concentrations and partitioning. Solids anlaysis included fractionation, particle size distributions (PSD) and specific surface area (SSA). Results indicated that Zn, Dc and Cu were mainly in dissolved form, and on an event basis exceeded USEPA and OEPA surface water quality standards. Based on characterization results, an in-situ treatment strategy called a partial exfiltration trench (PET) was developed. The PET functions by intercepting and infiltrating lateral pavement sheet flow influent while exfiltrating treated effluent to surrounding soils or to a perforated underdrain at the base of the trench. The body of the trench was filled with iron oxide coated sand (OCS) for adsorptive filtration of metal elements in the percolating stormwater. Results indicated that breakthrough capacity was controlled by particulate-bound metal element breakthrough. After one year of storm water loadings, PET removal efficiency exceeded 80 percent for dissolved and 70 percent for particlate-bound metal elements, respectively. Final rept. Sponsored by Federal Highway Administration, Columbus, OH. Ohio Div., Ohio Dept. of Transportation, Columbus. and National Science Foundation, Arlington, VA. 

Sansalone, J.J.; Buchberger, S.G. "An infiltration device as a best management practice for immobilizing heavy metals in urban highway runoff." Water Science and Technology 32:1, 1995. 119-125.
Abstract: Anthropogenic constituents in highway runoff metal elements and suspended solids which result from traffic activities, atmospheric deposition, roadway degradation and highway maintenance. A best management practice (BMP) for immobilizing heavy metals and suspended solids is a partial exfiltration trench (PET). A PET is designed to exfiltrate a percentage of infiltrated runoff to subsoil with the balance discharged through the underdrain. The PET functions through adsorptive-filtration, where dissolved metals are immobilized through sorption and metals associated with suspended solids are immobilized through filtration. An important PET design consideration is potential association of heavy metals with suspended solids. This paper investigates the correlation between heavy metals and suspended solids in highway runoff. Results indicate a strong positive correlation between heavy metal and suspended solid concentrations for snow washoff events and a poor correlation for rainfall-runoff events. Similar results are observed for correlations between metals and suspended particle sizes. From these findings, it is argued that a PET holds promise as a device for immobilizing metals associated with suspended solids transported during snow washoff and long duration rainfall events. 

Sansalone, J.J.; Koran, J.M.; Smithson, J.A.; Buchberger, S.G. "Physical characteristics of urban roadway solids transported during rain events." Journal of Environmental Engineering 124:5, May 1998. 427-440.
Abstract: Urban stormwater runoff from paved surfaces transports a wide gradation of solids ranging in size from smaller than 1 mu m to greater than 10,000 mu m. This study measured physical characteristics of solids transported in lateral pavement sheet flow from a heavily traveled roadway in Cincinnati. Particles smaller than 25 mu m were counted and sized using a light obscuration particle counter. Particles larger than 25 mu m were separated mechanically to generate particle size distributions. Solids in the 2-8 mu m range generated the largest counts and were rapidly washed from the pavement. LPSF rate and duration controlled yield and size of transported solids. Particle transport was mass limited during long duration high intensity events, but flow limited during intermittent low intensity events with high traffic. Particle counts exhibited a first flush from the pavement. Specific surface area generally increased with decreasing particle size, but measured values deviated from the monotonic pattern expected for spherical particles. Particles 425 to 850 mu m in size contributed the greatest total surface area. Results provide guidance for assessment of the impact of urban runoff water quality and for design of in situ treatment strategies. 

Schaefer, M. "Stormwater management: An environmental challenge beyond the 20th century." Water Engineering & Management 144:11, Nov 1997. 28-29.
Abstract: As development throughout the world booms, so does the potential for a variety of environmental problems and challenges. One such challenge facing engineers, developers, and regulators is how to deal with the increase in stormwater runoff on construction sites. Leading the charge to promote environmentally-sound stormwater management practices, the United States Environmental Protection Agency and other regulatory agencies began to study and promote effective stormwater management practices in the 1970s. This study and independent research by product manufacturers have resulted in the development of new products that can efficiently handle runoff created by small and large construction projects, better protecting the future of the environment. 

Schagrin, A. "Restoring streams key in city's stormwater work." American City and County 112:10, 1997. 78-80.
Abstract: In past decades, stream stabilization was a fairly cut-and-dried process: the waterways were merely lined with concrete. In Fairfax, Va., for example, a 1970 study had recommended that measure for the city's streams, although lack of funding prevented its implementation. But times change. And when Fairfax residents approved a $2 million bond issue in 1994 targeted at stormwater system improvements, the city finally had the necessary capital to counteract the negative effects of urban development on its drainage system. In reviewing its stormwater problems, the city determined that stabilizing area streams would be the most effective and economical first step. After researching new and innovative approaches to stream restoration, the public works department saw that bioengineering and stream morphology would be key in the effort. 

Shaw, J.K.E.; Watt, W.E.; Marsalek, J.; Anderson, B.C.; Crowder, A.A. "Flow pattern characterization in an urban stormwater detention pond and implications for water quality." Water Quality Research Journal of Canada, 32:1, 1997. 53-71.
Abstract: An assessment of flow patterns in an urban stormwater detention pond in Kingston, Ontario, was conducted using field measurement and mathematical modelling. Analysis of the field data and computer simulations revealed that the flow pattern in the pond is very dynamic and complex. The complexity of the flow behaviour results from wind stress on the pond surface. A combination of high wind and low inflow generates a circulation pattern dominant in the vertical plane of the pond. With relatively low wind stress, the velocity field is determined by inflow momentum and pond geometry (including bathymetry) and is characterized by circulation in the horizontal plane. Water quality becomes a concern during conditions of high wind and low inflow. The shear velocities associated with wind-generated current may be sufficiently large to prevent particle settling and, in extreme cases, to cause resuspension of unconsolidated deposited contaminated sediment, which may then enter the receiving waters. Regardless of the magnitude of inflow, the length to width ratio of the pond studied (3:2) and inflow momentum promote short-circuiting of the flow and limit the efficiency of settling. 

Struger, J.; Boyter, D.; Licsko, Z.J.; Johnson, B.D. "Environmental concentrations of urban pesticides." PROCEEDINGS OF THE 38TH CONFERENCE OF THE INTERNATIONAL ASSOCIATION OF GREAT LAKES RESEARCH. Ann Arbor: INTERNATIONAL ASSOCIATION FOR GREAT LAKES RESEARCH, 1995. 127.
Abstract: A study of two streams in Hamilton and two stormwater detention ponds in Guelph was initiated in 1991 determine the degree of urban pesticide contamination of aquatic systems. Surface water samples were analyzed for selected pesticides, during base flow and precipitation events. Sediment was analyzed for persistent organochlorine compounds and selected pesticides. A pesticide use questionnaire was circulated to residents of the subdivisions in which the detention ponds were located. Canadian Water Quality Guidelines (CWQG) for Drinking Water were not exceeded for any of the pesticides. Concentrations of 2,4-D did, however, exceed the CWQG for the Protection of Freshwater Aquatic Life (4 mu g/L) in 10% of the samples collected. The maximum observed concentration was 14.6 mu g/L. Eight other phenoxy acid herbicides were also detected. The organophosphorus insecticides diazinon, dimethoate, and chlorpyrifos were detected in water. The herbicides atrazine, metolachlor, and trifluralin were also detected in water. Eight persistent organochlorines were detected in sediment samples. Survey results indicated that over twenty pesticide compounds were used in 1991. Sixty-six per cent of the lawns in the two subdivisions received at least one pesticide application and 36% of the homes used a professional lawn care service. Urban pesticide application rates were higher than agricultural rates for a number of compounds. 

Symader, W.; Bierl, R. "The heterogeneity of runoff and its significance for water quality problems." Hydrological Sciences Journal/Journal des Sciences Hydrologiques 43:1, Feb 1998. 103-113.
Abstract: In a small heterogeneous limestone basin with mixed land use twelve flow components were distinguished by using chemographs of flood events and baseflow. Only a few of them are endmembers. The number of flow components depends on the tracers that are used and on the degree of heterogeneity. If the concept of flow components is restricted to endmembers only, the runoff generation process cannot be explained completely because runoff does not form by the mixing of chemically distinct water types alone. Beside water types, there are all kinds of temporal variations ranging from steep gradients to continuous changing, e.g. due to incomplete mixing, exhaustion of sources, etc. This means that the original concept of flow components should be extended to behaviour patterns in order to obtain a basic understanding of the very complex process of runoff generation. Furthermore it is an excellent approach to facilitate understanding of the temporal variation of water quality in flowing waters. 

Tanaka, Y.; Miyajima, K.; Funakosi, T.; Chida, S. "Filtration of municipal sewage by ring shaped floating plastic net media." Water Research 29:5, 1995. 1387-1392.
Abstract: Characteristics of floating media filtration were examined to develop a process for primary treatment of municipal sewage during dry weather and high-rate treatment of combined sewer overflow during stormy weather. The media used for filtration were ring-shaped polypropylene net (2.2 cm in diameter, 2.5 cm in length and 6 mm in mesh size), which characteristically has a high void ratio (90%) and a low specific gravity (0.93). Experiments with bench scale and pilot scale filters showed that the removal rates of pollutants were 80-90% for suspended solids and 44% for BOD sub(5) under an operating condition of 1000 m/day of flow velocity and 2-3 mg/l of cationic polyelectrolyte addition. Mass capture reached 7-10 kg/m super(3) with a low head loss, less than 0.2 m, with a media depth of 2 m. High removal rate of suspended solids and low head loss should be principal advantages of the process. 

Thomas, J.F.; Gomboso, J.; Oliver, J.E.; Ritchie, V.A. Wastewater re-use, stormwater management, and the National Water Reform Agenda Research Position Paper. CSIRO Land and Water, 1997.
Abstract: This report presents possible policy directions for wastewater re-use and improved stormwater management, given the emerging water sector framework set out in the COAG National Water Reform Agenda. The strategic framework for reform of the Australian water sector involves environmentally sustainable management of wastewater and stormwater from metropolitan and town water services. Specifically, an improved quality of natural environment needs to be sustained in urban regions, including the marine and estuarine environments of coastal cities, and the riverine or lacustrine environments of inland cities and towns. In general, more intensive management of water supply systems is recommended, including: the use of reclaimed water within municipal and industrial systems, the capture, storage, distribution and use of hitherto 'uneconomic' near-urban sources, such as local stormwater either of high initial quality or with treatment, and introduction of a quality-differentiated water supply: i.e., matching the quality and reliability of water supplied to each market segment to that actually needed by the user. Improved management of the urban water cycle is needed to address growing problems of pollution, and to enhance the amenity values of urban waters. 

Udall, C.H. "Recovery of 'lost' storm water from local wash beds." Water Resources Bulletin 31:4, 1995. 737-744.
Abstract: Most of the precipitation that falls is unused because it never reaches a stream or recharges an underground supply. This storm water evaporates and is transpired and consumed by plants. Described below are pertinent legal principles and the concept for a small-scale system to capture and store some of this "lost" storm water from the subflow of small gravelly washes that are not part of or connected with a stream system. The subsurface flow is interrupted by an elastomer faced earthen barrier (dam) and stored in a gravel bed. Both the barrier and the gravel storage bed are situated below the surface of the wash bed. If the gravel bed is not underlain by a natural substratum that is relatively impervious, it is either placed on a liner of suitable compacted clay or is underlain with an elastomeric membrane to limit the downward infiltration and loss of the stored water. A system may be used to capture and store subflow after surface flow has ceased and during periods of drought; to supply household and irrigation water; to exercise Winters Doctrine rights; and to replace small dams and surface impoundments by underground storage of the captured water to ensure a more reliable and sanitary supply for livestock and wildlife. A system is most effective in desert regions where (or when) both stream and ground water are unavailable; where rainfall is infrequent, but in storms resulting in rapid runoff; and where land surface topography and morphology coincide to form sites that permit the productive use of a system. A system should not be installed without sound legal and hydrological advice. Careful engineering is essential to the safe and proper design of a system, especially its subsurface barrier. 

Van Buren, M.A.; Watt, W.E.; Marsalek, J. "Removal of selected urban stormwater constituents by an on-stream pond." Journal of Environmental Planning and Management 40:1, Jan 1997. 5-18.
Abstract: A methodology is presented for assessing the pollution control performance of an on-stream stormwater pond, and the application of this methodology to a specific facility in Kingston, Ontario, Canada is documented. This assessment is based on constituent mass balances for both baseflow and event conditions. Results on removal rates are provided for selected dissolved constituents, nutrients, suspended solids, metals and organic contaminants. In summary, dissolved constituents exhibit zero removal for baseflow periods and positive removal for events; nutrients and suspended solids exhibit negative removal for baseflow periods and positive removal for events; and metals and organics exhibit positive removal for both baseflow periods and events. Constituent removal appears to be controlled mainly by physical processes (sedimentation), and the uncertainties associated with the estimates of constituent loads are quantified. 

Walker, K.P.; DeGuida, R.N. "Urban runoff and combined sewer overflow." Water Environment Research 67:4, 1995. 414-419.
Abstract: The article is a review of construction and design and methods, as well as results of systems for combined sewers and control of overflow in several cities. 

Wong, T.H.F.; Geiger, W.F. "Adaptation of wastewater surface flow wetland formulae for application in constructed stormwater wetlands." Ecological Engineering 9:3-4, Dec 1997. 187-202.
Abstract: Over the past 30 years, the use of constructed wetlands for wastewater treatment has been a topic of significant research culminating in a good data base from which simplistic equations have been derived to aid in the design of these facilities to meet long term water quality treatment performance criteria. Over the past decade, the use of treatment wetlands has extended to stormwater and combined sewer overflow (CSO) management applications. Designing constructed wetlands for stormwater and CSO applications have unique challenges stemming from the highly stochastic nature of the hydraulic and pollutant loading on a stormwater wetland compared with wastewater treatment systems. This paper explores the possibility of adapting the simplistic models for wastewater wetlands for interim use in developing design guidelines for stormwater wetland systems. A procedure that takes into account the unsteady intermittent nature of stormwater inflows to these wetlands has been incorporated into one of these simplistic models and a case study presented to demonstrate the application of the procedure. 

Yonge D.R.; Price F. "Stormwater Contaminant Removal by Chemicals." Govt Reports Announcements & Index, Issue 20. Springfield, VA: NTIS, 1995.
Abstract: TD3: The Washington State Department of Transportation designs, operates, and maintains stormwater detection basins for flood control. Initiatives by the Washington State Department of Ecology have prioritized the consideration of stormwater quality as well as quantity for stormwater treatment. Modification of existing stormwater detention basins could afford an efficient mechanism for addressing water quality by enhancing contaminant removal. A scale model of a typical basin was constructed to investigate contaminant removal capabilities of existing detention basins. A simulated highway stormwater runoff was formulated and applied in scale model detection basin testing over a range of flow rates. Four coagulants were evaluated for their ability to enhance removal of sediment and metals. Research summary rept. Prepared in cooperation with Sunshine Mining Corp., Kellogg, ID. Sponsored by Washington State Dept. of Transportation, Olympia. and Federal Highway Administration, Olympia, WA. Washington Div. 

Yu S.L.; Fitch G.M.; Earles T.A.; Wolfe D.D. "Constructed Wetlands for Nonpoint Source Pollution Control." Govt Reports Announcements & Index, Issue 02. Springfield, VA: NTIS, 1999.
Abstract: TD3: This report presents the results of research to evaluate the potential of utilizing mitigated wetlands as stormwater Best Management Practices (BMPs). Results of wetland monitoring, wetland modeling, and geographic information system (GIS) development are presented. Average removal rates as high as 90% for total suspended solids (TSS), 65% for chemical oxygen demand (COC), 70% for total phosphorus (TP) and orthophosphate (OP), and 50% for zinc (Zn) were observed at study sites. A mathematical model of transport of a pollutant in dissolved and particulate forms in a two-segment, two-state system was developed. The model includes settling, diffusion, adsorption to plant and substrate, and vegetative uptake mechanisms. A GIS was developed to improve management of existing mitigated wetlands and to aid in siting of future mitigation sites. A link between a watershed model and this GIS is also described. The report concludes that mitigated wetlands may be as effective as conventional BMPs at improving the quality and at controlling the quantity of highway storm runoff. Final rept. Dec 94-Mar 98. Available in original stock only. See also PB92-102359. Sponsored by Virginia Dept. of Conservation and Recreation, Richmond, VA. Div. of Soil and Water Conservation. and Federal Highway Administration, Richmond, VA. Virginia Div. 

Yu S.L.; Fitch G.M.; Earles T.A. "Constructed Wetlands for Stormwater Management." Govt Reports Announcements & Index, Issue 02. Springfield, VA: NTIS, 1999.
Abstract: TD3: This report presents the results of research to evaluate the potential of utilizing mitigated wetlands as stormwater Best Management Practices (BMPs). Results of wetland monitoring, wetland modeling, and geographic information system (GIS) development are presented. Average removal rates as high as 90% for total suspended solids (TSS), 65% for chemical oxygen demand (COC), 70% for total phosphorus (TP) and orthophosphate (OP), and 50% for zinc (Zn) were observed at study sites. A mathematical model of transport of a pollutant in dissolved and particulate forms in a two-segment, two-state system was developed. The model includes settling, diffusion, adsorption to plant and substrate, and vegetative uptake mechanisms. A GIS was developed to improve management of existing mitigated wetlands and to aid in siting of future mitigation sites. A link between a watershed model and this GIS is also described. The report concludes that mitigated wetlands may be as effective as conventional BMPs at improving the quality and at controlling the quantity of highway storm runoff. Final rept. Dec 94-Mar 98. Sponsored by Virginia Dept. of Transportation, Richmond. and Federal Highway Administration, Richmond, VA. Virginia Div. 

Zimmerman, M.; Murphy, C. "Best management practices for storm water at industrial facilities." Water, Air and Soil Pollution 90;1-2, Jul 1996. 153-162.
Abstract: Contaminated storm water runoff has been identified as a significant source of degradation to our nation's waterways. Industrial and construction activities are primary sources of this contamination. After identifying this problem, Congress passed the Clean Water Act Amendments of 1987 which required EPA to publish regulations to control storm water discharges from certain activities. As a result, industrial facilities subject to the program are required to obtain permits and implement controls referred to as Best Management Practices (BMPs) to reduce the pollutants in the storm water runoff from their sites. BMPs can be implemented to reduce contaminants from entering storm water (source controls) or to treat storm water after it has contacted industrial areas (treatment controls). In general, source controls are more effective in reducing pollutant levels in storm water runoff, and are therefore, preferred by EPA and other regulatory agencies. This paper provides an overview of the EPA Storm Water Program which also applies to most state programs and discusses methods to identify and implement BMPs. 
 

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