Module 4: The Problem of Stormwater Runoff

1. Module 4: The Problem of Stormwater Runoff Receiving Water Uses, Impairments, and Sources of Stormwater Pollutants

2. Module 1: The Problem • Introduction • Receiving Water Beneficial Use Impairments • Causes of Receiving Water Use Impairments • Major Urban Runoff Sources

3. ““Bathing in sewage-polluted seawater carries only a negligible risk to health, even on beaches that are aesthetically very unsatisfactory.” Committee on Bathing Beach Contamination Public Health Laboratory Service of the U.K. 1959 What do you make of this statement? Source: Burton, A.G. and R.E. Pitt. 2002. Stormwater Effects Handbook: A Toolbox for Watershed Managers, Scientists, and Engineers. Lewis Publishers. Boca Raton, FL. 929 pp.

4. Introduction • In the Past – Assumptions made that periodic combined sewer overflows (CSOs), or even raw sewage discharges, produced negligible human health risks Source: Burton, A.G. and R.E. Pitt. 2002. Stormwater Effects Handbook: A Toolbox for Watershed Managers, Scientists, and Engineers. Lewis Publishers. Boca Raton, FL. 929 pp.

5. Introduction Source: Burton, A.G. and R.E. Pitt. 2002. Stormwater Effects Handbook: A Toolbox for Watershed Managers, Scientists, and Engineers. Lewis Publishers. Boca Raton, FL. 929 pp. • About 57% of surveyed rivers and streams support the designated uses • Designated uses range from the stream being fishable and swimmable to supplying drinking water for human consumption • The fishable use is designed to protect aquatic organisms, such as fish, while the swimmable use is designed to protect human health during primary (swimming) and secondary (fishing) contact

6. Introduction • The leading pollutants identified were: • Bacteria • Siltation • Nutrients • Oxygen-depleting substances Source: Burton, A.G. and R.E. Pitt. 2002. Stormwater Effects Handbook: A Toolbox for Watershed Managers, Scientists, and Engineers. Lewis Publishers. Boca Raton, FL. 929 pp. • Leading Sources: • Agriculture • Municipal Point Sources • Habitat Modification • Urban Runoff

7. Introduction • 57% of the rivers and streams in the United States fully support their beneficial uses (Figure 2.1) • A wide variety of pollutants and sources are the cause of impaired uses • Runoff from urban and agricultural sources • major source of pollutants • runoff is nonpoint source pollution

8. Introduction • Point Source of pollution

9. Introduction • Most research – based in urban settings • Why????

10. Introduction • Completely urbanized watersheds – small urban streams are commonly severely degraded • Typically have no official beneficial uses or monitoring programs (and may be intermittent in flow) Would you recognize this concrete ditch as an impacted stream?????

11. Introduction

12. Introduction What type of pollutants might you expect in a rural stream????

13. Introduction Sediment Nutrients Herbicides

14. Introduction • What water quality risks might be present in urban streams?

15. Introduction • Contaminated sediments • Metals – Lead, mercury, etc. • Organics – PCBs • Bacterial contamination • E. coli • Fecal coliform bacteria • What would be the health risks?

16. Introduction • Wet-weather flows from relatively large cities discharging into large waterways may not be associated with obvious in-stream detrimental conditions. • Why??

17. Introduction

18. Introduction • Would you expect acute toxicity to be related to stormwater???? EPA Analytical Methods Whole Effluent Toxicity Testing

19. Introduction • Effects of continuous levels of single stressors (e.g., dissolved oxygen, temperature, copper, DDT, diazinon, chlorpyrifos) on a wide variety of common aquatic species are known • Effects that the single stressors have, or may have, in stormwater are therefore known with reasonable certainty

21. Introduction • What type of problem does Table 2.1 suggest that we have regarding stormwater?

22. Introduction • Attributes of each stormwater event are a result of: • Previous meteorological conditions (e.g.,dry deposition, air patterns, humidity) • Land use patterns (e.g., traffic and parking patterns, construction and landscaping activities) • Storm intensity and duration • Watershed characteristics • Extreme heterogeneity in stormwater and its associated quality • So, how about predicting effects?

23. Introduction • Stressors may interact to varying degrees: • Antagonistic – constituents that counteract or neutralize each other's effect • Additive – constituents that interact to produce an effect that is the sum of the parts • Synergistic – constituents that work together so the total effect is greater than the sum of the two (or more)

24. Introduction • Stormwater may Interfere with Beneficial Uses in Many Ways • Substantial runoff increase in urban streams • Increased frequency of floods • Increased magnitude of floods • Increased stormwater runoff may cause • Habitat alteration in urban streams • Enlarge stream cross sections • Channel erosion • Unstable conditions • Removal of vegetation and woody debris by residents • Increased erosion • Decreased bank stability • Loss of habitat • Increased erosion from construction sites • Sedimentation in streams – smothers course sediment • Reduction of stream habitat - pools • Increased turbidity • Increases in stream contaminants • Chemicals • Trash • Litter • How could these changes impact beneficial uses in Kentucky? (See regulations)

25. Introduction • What could influence the degree of impairment? • Aquatic Life Use – habitat for aquatic life • Recreational Use – human contact use • Human Health Use • Drinking water • Food supply

26. WAH - Warm Water Aquatic Habitat CAH - Cold Water Aquatic Habitat PCR - Primary Contact Recreation (swimming) SCR - Secondary Contact Recreation (fishing, boating, canoeing) DWS - Domestic Water Supply, applicable at existing points of public water supply withdrawal OSRW - Outstanding State Resource Water

27. Introduction • What could influence impairment? • Aquatic Life Use • Contaminant levels • Physical • Chemical • Species - sensitivity • Life stage - sensitivity • Predator-prey relationships • Food sources • Competition • Behavior changes

28. Introduction • What could influence impairment? • Recreational Use • Individual and population sensitivities • Age • Health status • Genetics • Contaminant Levels • Physical Chemical • Trash and debris – safety • Turbidity - safety • Usage pattern • Frequency of use • Duration of use • Types of recreation – degree of contact

29. Introduction • What could influence impairment? • Human Health Use • Individual and population sensitivities • Age • Health Status • Genetics • Contaminant levels • Turbidity • Chemicals • Pathogens • Drinking water treatment efficiency • Point of use treatment • Amount of water consumed • Use of aquatic species and wildlife as food sources • Contamination levels • Contaminant type • Usage Pattern • Aquatic species consumption levels (meals/week, meals/month) • Amount of consumption per meal

30. Beneficial Use Impairments • With some planning and use of stormwater drainage controls the most basic goals in most watersheds may be met. • Stormwater conveyance • Aesthetics

31. Beneficial Use Impairments • With basic stormwater controls, installed at the time of development and protection of stream • May achieve partial to full Aquatic Life use

32. Beneficial Use Impairments • Water contact recreation, consumptive fisheries, and water supplies may not be appropriate goals for heavily urbanized or developed watersheds. • Human Health goals and uses may be possible in urban areas where: • Receiving waters are large • Watersheds drain large undeveloped areas

33. Beneficial Use Impairments • Stormwater Uses • Toilet flushing • Irrigation • Fire fighting • Stormwater reservoir • Wetland habitat • Fountains • Streams • Nature and landscape observations • May require basic treatment: filtration

34. Causes of Receiving Water Use Impairments • Aquatic Life Uses • Habitat destruction • Chronic pollutant exposures • Water column • Sediment • Pulse exposures • Suspended solids • Water column

35. Causes of Receiving Water Use Impairments • http://www.epa.gov/OWOW/NPS/urbanize/report.html • Urbanization and Streams: Studies of Hydrologic Impacts

36. Causes of Receiving Water Use Impairments • http://www.epa.gov/OWOW/NPS/urbanize/report.html • Urbanization and Streams: Studies of Hydrologic Impacts • EPA Waters Site - http://www.epa.gov/waters/