Module 3: Stormwater Effects and Pollutant Sources Identify - - PowerPoint PPT Presentation

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Photo by Lovena, Harrisburg, PA

Module 3: Stormwater Effects and Pollutant Sources

Robert Pitt, P.E., Ph.D., DEE Department of Civil and Environmental Engineering The University of Alabama

Presentation based on material further discussed in: Burton, G.A. Jr., and R. Pitt. Stormwater Effects Handbook: A Tool Box for Watershed Managers, Scientists, and Engineers. ISBN 0-87371-924-7. CRC Press, Inc., Boca Raton, FL. 2002. 911 pages.

Stormwater Management Steps

• Identify beneficial use impairments
• Identify causes of impairments
• Identify sources (magnitude, seasonality,

flow phases, etc.) of problem constituents

• Identify, select, and design controls

suitable for problem pollutants and locations

• Implement controls, conduct validation

monitoring, modify controls as needed

Major Receiving Water Beneficial Uses

• Stormwater Conveyance (flood prevention)
• Recreation (non-water contact) Uses
• Biological Uses (Warm water fishery,

aquatic life use, biological integrity, etc.)

• Human Health Related Uses (Swimming,

Fishing, and Water Supply)

WI DNR photo

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Basic Goals for Urban Streams

• Stormwater conveyance and aesthetics should

be the basic beneficial use goals for all urban waters.

• Biological integrity should also be a goal, but

with the realization that the natural stream ecosystem will be severely modified with urbanization.

– “Biological integrity is the capacity to support and maintain a balanced, integrated and adaptive biological system having the full range of elements [the form] and process [the function] expected in a region’s habitat.” James Karr 1991, modified

• Certain basic stormwater controls at the time
• f development, plus protection of stream

habitat, may enable partial use of some of these goals in urbanized watersheds.

• Water contact recreation, consumptive

fisheries, and water supplies are not appropriate goals for most heavily urbanized watersheds.

Receiving Water Effects of Water Pollutant Discharges

• Sediment (amount and quality)
• Habitat destruction (mostly through high flows

[energy] and sedimentation)

• Eutrophication (nutrient enrichment)
• Low dissolved oxygen (from organic materials)
• Pathogens (mostly from municipal wastewater and

agricultural runoff)

• Toxicants (heavy metals and organic toxicants)
• Temperature
• Debris and unsafe conditions
• etc.

Historical concerns focused on increased flows during rains and associated flooding. However, decreased flows during dry periods are now seen to also cause receiving water problems.

WI DNR photo

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Bank instability and habitat destruction due to increased flows

WI DNR photos

Sediment transported in stormwater causes significant receiving water impacts.

WI DNR photo

• R. Bannerman photo

One Early Method of Getting Rid of Wastewater

Coombs and Boucher

Wastewater treatment has only been around since the late 1800s. People dumped wastes into gutters and ditches,

• r sometimes out an
• pen window. Wastes

then flowed into nearest stream or pond. “Sewer” is from the old English meaning seaward.

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Polluted New York Harbor in 1883

Coombs and Boucher

Gross floatables most important wet weather flow pollutant in many urban areas.

Basic Wastewater Conveyance in Sanitary Condition not Always Achieved

McKinney and Schoch

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Sewage contamination of storm drainage system

Beach Closings in the US in 1994

(Water Envir. & Tech. 1995)

106 (7.8%) Wastewater Treatment Plant Malfunctions 136 (10%) Agricultural Runoff 194 (14%) Combined Sewer Overflows (CSOs) 345 (25%) Stormwater Runoff 584 (43%) Sanitary Sewer Overflows (SSOs) Public swimming beach located in utility right-of-way adjacent to stormwater outfall (not uncommon) Children frequently play in urban creeks, irrespective

• f their designation as water contact recreation waters

WI DNR photo

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Fishing in urban waters also occurs, both for recreation and for food.

WI DNR photo

Historical approach to urban drainage has been devastating to environment and recharge of groundwaters

WI DNR photo WI DNR photo

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Eutrophication dramatically detracts from recreational uses, along with affecting aquatic life

WI DNR photos

Inappropriate discharges, including accidental hazardous material releases, into storm drainage can cause acute receiving water effects.

Cuyahoga River in Cleveland Often Caught

• n Fire Between 1952 and 1969

Coombs and Boucher

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Whatcom Creek, Bellingham, WA, fire-fighting foam

Fire from 200,000 gallons of spilled gasoline in residential area from pipeline rupture (June 1999)

Bellingham Herald (Washington) Birmingham News (Alabama)

Alabama has about 200 transportation accidents a year involving hazardous materials. This is typical for most states.

Groundwater Contamination

The potential for groundwater contamination associated with stormwater infiltration is often asked.

Book published by Ann Arbor Press/CRC, 219

• pages. 1996, based on

EPA research and NRC committee work.

Road cut showing direct recharge of Edwards Aquifer, Austin, TX

http://civil.eng.ua.edu/~rpitt/Publications/BooksandReports/ Groundwater%20EPA%20report.pdf

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Barton Springs, Austin, TX

Example Weak-Link Model Influencing Factors

very low very low moderate Lead high intermediate high Pyrene moderate intermediate low Anthracene very low intermediate moderate Chlordane high mobile low/moderate Nitrates Filterable Fraction (treatability Mobility (sandy/low

• rganic soils)

Abundance in Stormwater Constituent

Links Depend on Infiltration Method

(contamination potential is the lowest rating of the influencing factors)

• Surface infiltration with no pretreatment (grass

swales or roof disconnections)

– Mobility and abundance most critical

• Surface infiltration with sedimentation

pretreatment (treatment train: percolation pond after wet detention pond)

– Mobility, abundance, and treatability all important

• Subsurface injection with minimal pretreatment

(infiltration trench in parking lot or dry well)

– Abundance most critical Moderate to High Groundwater Contamination Potential

Chloride Chloride Chloride Nickel, chromium, lead, zinc Enteroviruses, some bacteria and protozoa Enteroviruses Enteroviruses 1,3-dichlorobenzene, benzo (a) anthracene, bis (2-ethylhexl phthalate), fluoranthene, pentachlorophenol, phenanthrene, pyrene Fluoranthene, pyrene Benzo (a) anthracene, bis (2-ethylhexl phthalate), fluoranthene, pentachlorophenol, phenanthrene, pyrene Lindane, chlordane Lindane, chlordane

Injection after Minimal Pretreatment Surface Infiltration after Sedimentation Surface Infiltration with no Pretreatment

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Basic Premise for Receiving Water Assessments

• No one single approach can be

routinely used to accurately determine

• r predict ecosystem health and

beneficial use impairment.

• Each assessment approach or

component has associated strengths and weaknesses.

Major Components of Receiving Water Assessments

• Chemical (major impairments and uses)
• Biological (community tolerance)
• Physical/habitat (ecological integrity)
• Toxicity (availability of chemical

contaminants) The complexity of ecosystems require that these assessment tools be used in an integrated manner.

Reported State’s Bioassessment Tools

• macroinvertebrate surveys (almost all programs,

but with varying identification and sampling efforts)

• habitat surveys (almost all programs)
• some simple water quality analyses
• some watershed characterizations
• few fish surveys
• limited sediment quality analyses
• limited stream flow analyses
• hardly any toxicity testing
• hardly any comprehensive water quality analyses

The main objectives of most monitoring studies may be divided into two general categories:

• Characterization (quantifying a few simple

attributes of the parameter of interest ), and/or

• comparisons (to standards or reference

conditions). Other common objectives include identifying hot spots, examining trends, etc.

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Experimental Design Issues

• Budget
• Basic Study Approach
• Duration
• Sampling Effort
• Sampling Locations
• Data Analyses
• Quality Control/Quality Assurance

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Basic Study Approach

Experimental designs can be organized in one

• f the following basic patterns:
• 1. Parallel watersheds (developed and

undeveloped)

• 2. Upstream and downstream of a city
• 3. Long-term trend

Preferably, most elements of all of the above approaches can be combined in a staged approach

Parallel Stream Study (urban and rural stream) (Bellevue, WA)

urban urban rural rural Large Rain Small Rain

Longitudinal Trend Study (above and below city) (San Jose, CA)

Long-Term Trend Study (Sweden)

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Likely Follow-up Testing

• Short-term chronic toxicity testing with

additional species (lab and in situ),

• Increased testing of toxicants,
• Characterizing fish, plankton, periphyton, or

mussel populations,

• Measuring assimilative capacity via long

term BOD and SOD testing, and/or

• Measuring productivity with light/dark bottle

BOD in situ tests.

Source Area Monitoring to Predict Sources of Runoff Pollutants

• Controlled washoff tests
• Small area sheetflow sampling
• Large area sheetflow sampling
• Outfall monitoring

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Stormwater quality can vary greatly, even at a single site. Variations between events is greater than variations within events.

WI DNR photo

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Stormwater NPDES Data Collection and Evaluation Project

• The University of Alabama and the Center for Watershed

Protection were awarded an EPA 104(b)3 grant in 2001 to collect, review, and analyze selected Phase 1 NPDES stormwater permit data.

• We created a national database, the National Stormwater

Quality Database (NSQD), that is available on the Internet, as version 1.1.

• We received an extension of the project in 2005 to expand

the database to include under-represented areas. We are currently preparing version 3.1 of the database (version 2 was not posted as it was an interim version that had not undergone complete QA/QC reviews).

Version 3 incorporates version 1.1 data, plus additional MS4 data, along with selected data from the International BMP Database, the USGS, and NURP.

Communities Included in NSQD version 3

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100 8,602 TOTAL 2 197 Zone 9- Midwest 0.3 24 Zone 8- Rocky Mountains 10 865 Zone 7- Northwest 5 417 Zone 6- Southwest 9 799 Zone 5- Texas 4 301 Zone 4- Lower Mississippi Valley 9 744 Zone 3- Southeast 46 3,984 Zone 2- Mid Atlantic 15 1,271 Zone 1- Great Lakes and Northeast PERCENTAGE TOTAL EVENTS RAIN ZONE Number of Events and Geographical Coverage in NSQD ver. 3 100 8,602 TOTAL 5 404 Open Space 9 763 Freeway 3 269 Mixed Industrial 10 887 Industrial 1 115 Institutional 6 525 Mixed Commercial 15 1,288 Commercial 15 1,245 Mixed Residential 35 2,979 Residential PERCENTAGE TOTAL EVENTS LAND USE Number of Events and Land Use Coverage in NSQD ver. 3

2.2 1.7 1.5 1.5 1.7 1.6 COV 6,747 443 488 420 3,466 1,132 Count 136 126 138 95 97 155 Mean ALL 2.0 0.9 1.0 1.6 1.7 1.2 COV 2,346 170 107 122 1,388 332 Count 114 100 109 107 85 140 Mean Residential 1.6 1.2 1.6 1.3 1.0 1.4 COV 683 24 43 82 304 100 Count 160 182 244 96 78 177 Mean Industrial 1.8 1.1 1.6 2.0 1.8 1.2 COV 934 42 40 50 454 237 Count 110 81 67 60 86 135 Mean Commercial All 7 5 3 2 1

Total Suspended Solids by Land Use and Geographical Area (mg/L)

These grouped box-whisker plots sort all of the data by land

• use. Kruskal-Wallis analyses

indicate that all constituents have at least one significantly different category from the

• thers. Heavy metal differences

are most obvious.

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Residential area concentrations grouped by EPA rain zones. Zones 1-4 are east half of country, zones 5-9 are western half

• f country. Zones 3 and 7

are the wettest zones.

These grouped box-whisker plots sort residential data by sampling season. The most

• bvious difference is shown for

fecal coliforms (a similar conclusion was found during NURP, EPA 1983). (These plots are only for residential data)

Comparison of Control Practices (Residential Land Uses EPA Rain Zone 2)

In-Stream and Laboratory Biological and Toxicity Assessments needed to Identify and Quantify Actual Receiving Water Problems

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Contaminated sediments in urban receiving waters likely much more responsible for biological impacts than contaminated water. Fish surveys in urban streams typically find similar biomass as in control streams, but sensitive native fish displaced by hardy exotics

WI DNR photo

Benthic macroinvertebrate populations on natural and artificial substrates have been extensively used to indicate receiving water effects.

EXCELLENT GOOD FAIR POOR 10 20 30 40 50 60 70 80 90 100 10 20 30 40 50 60 70 80 90 100 Watershed Urbanization (%TIA) 5 10 15 20 25 30 35 40 45 Benthic Index of Biotic Integrity (B-IBI) Riparian Integrity Biotic Integrity

• C. May 1996

Toxicity tests using stormwater find much of the toxicity associated with small particulates, not just filtered portions of the water.

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Interstitial water in urban sediments highly contaminated and directly affected by contaminated sediment

WI DNR and USGS tests

Side-stream bioassay tests show chronic toxicity after about 1 to 2 weeks of exposure to urban stream water, and no 96- hr toxicity

Side-stream bioassay tests demonstrated the benefits of stormwater controls for the removal

• f fine particulates.

Residual toxicity remains, however.

WI DNR and USGS tests

Conclusions

• We can learn from the past several

decades of receiving water investigations

• Problems are site specific and require

sequential investigations

• Must use combination of study

components, including:

• habitat evaluations,
• rain and flow monitoring,
• chemical, and biological monitoring, and
• toxicity investigations

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Conclusions (continued)

• Must evaluate both sediment and water

in most cases

• All flow phases (dry and wet weather)

and seasons (including snowmelt) may be important

• May require extensive and long-term

effort to obtain data with small uncertainty

• Need to balance resources with study
• bjectives