Urbanization increases stormwater runoff rates, volumes, and frequencies, impairing water quality through pollution and physical alterations to watersheds. The regulatory solution is the Stormwater Program under the Clean Water Act, which requires National Pollutant Discharge Elimination System permits for "point source" stormwater discharges. Permits regulate both municipal separate storm sewer systems and industrial facilities, and cover elements such as education, illicit discharge detection, construction site controls, and post-construction runoff management. Low impact development techniques aim to restore natural hydrology and protect water quality.

1. Urban Runoff
Greg Gearheart
State Water Resources Control Board

2. Urban Runoff Problems
• Pollution
– Beach closures
– Water quality impairment
– Fish kills
– Plastic debris
• Physical alteration of the
watershed / water bodies
– Stream incision / erosion / deposition
– Habitat destruction

8. Hydrologic Changes
Runoff
Time
Pre-Development
Urbanization
tends to increase
storm water
runoff:

peak flows

volume

frequency
Post-Develop.
From Haltiner (2006)

13. Regulatory Solution
• Stormwater Program
– A Clean Water Act-based program
– A permitting solution
– “Forces” stormwater peg into the
existing hole designed to protect
surface waters
– Has evolved over the years to include
new tools and connect to TMDLs

14. Overview of the Clean Water
Act
• Federal Water Pollution Control Act of
1972, amended 1977
– NPDES programs
– Permits are a privilege, not a right
– Effluent limits must be both technology and
water quality based
• 1987 – added Section 402(p) to CWA
covering stormwater

15. Overview of the Clean Water
Act
• All “point sources”
• “Discharging a pollutant”
• Into a “Water of the U.S”
>>>>Must obtain a NPDES (National
Pollutant Discharge Elimination
System) Permit

16. What is a Point Source ?
• Point Source
– Discharge though a discrete
conveyance into waters of the US
• Industrial facilities
• Sewage treatment plants
• Stormwater from industrial sites and
storm sewers
– Non-point source
• Runoff that is not a point source

17. What is a Water of the
U.S ?
• All waters currently used, used in
the past, or susceptible to use for
interstate commerce including all
waters which are subject to the ebb
and flow of the tide

18. US Waters – Examples
• Rivers, lakes and streams
• Tributaries
• Territorial seas
• Wetlands
• Ephemeral washes

19. Stormwater Program Overview
• Municipal Program – urban runoff
• Industrial Program – industrial
sector specific runoff
• Program Overlap
– Many industrial sites discharge INTO
Municipal Separate Storm Sewer
Systems (MS4s)

20. Municipal Stormwater
Permits
• Municipal Separate Storm Sewer
Systems (MS4s)
– Phase I
• Municipalities > 100,000 population
– Phase II
• Small municipalities and others
– 9th
circuit court decision 1992

22. MS4 – Phase 1
• 26 Regional Water Board Phase I
MS4 Permits
• Covering over 1000 entities in CA
• 1 Statewide - Caltrans Permit

23. Municipal Permits
• Municipal permits (under Phase I) areMunicipal permits (under Phase I) are
issued by Regional Boards for:issued by Regional Boards for:
• Municipalities > 100,000Municipalities > 100,000
• Contiguous municipalities sharing aContiguous municipalities sharing a
large MS4large MS4
• Small municipalities covered underSmall municipalities covered under
Phase II regulationsPhase II regulations

24. MS4 Phase II – 6 Minimum
Program Elements
• Education an Outreach
• Public Participation/Involvement
• Illicit Discharge Detection and
Elimination
• Construction Site Runoff Control
• Post Construction Runoff Control
• Pollution Prevention/Good
Housekeeping

25. MS4 – Phase I Issues
• June 19, 2006 - State Water Board released Blue
Ribbon Panel Report
• Municipal Discharges - Panel Recommended
• (Action Levels and improve accountability)
• Impaired water bodies and TMDLs are being
implemented through MS4 permits
• Over 1000 cities, counties, and other governmental
agencies regulated – significant

26. MS4 – Phase II
• Current permit requires MS4s to
enroll and for Rbs to approve SWMP
• About 150 MS4s currently “covered”
• New Phase II permit being drafted

27. Industrial Stormwater
Permits
• Industrial General Permit (SB Order
97-03-DWQ)
– Sector/SIC code specific
• Construction General Permit (SB
Order No. 99-08-DWQ)
– Construction and development industry
– All projects that disturb 1 acre or
more of land must obtain coverage

30. DRAFT Program report cards developed by Rafael Maestu in the Office of Research, Planning and Performance

31. Industrial Facilities
DRAFT Program report cards developed by Rafael Maestu in the Office of Research, Planning and Performance

32. DRAFT Program report cards developed by Rafael Maestu in the Office of Research, Planning and Performance

33. Industrial Facilities
DRAFT Program report cards developed by Rafael Maestu in the Office of Research, Planning and Performance

34. Industrial Permit
• Over 500 Standard Industrial
Codes (SIC) regulating specific
industries
• Landfills, auto dismantlers,
refineries, plastic products, etc.
• Plastic

35. DRAFT Program report cards developed by Rafael Maestu in the Office of Research, Planning and Performance

36. Construction
DRAFT Program report cards developed by Rafael Maestu in the Office of Research, Planning and Performance

37. DRAFT Program report cards developed by Rafael Maestu in the Office of Research, Planning and Performance

38. Construction
DRAFT Program report cards developed by Rafael Maestu in the Office of Research, Planning and Performance

39. Plastic Debris Program
• ~400 facilities regulated under the
industrial general permit (IGP)
• ~3000 facilities statewide that
handle preproduction plastic pellets
in some manner
• Part of global problem – fate and
transport in the environment of
plastic is impressive

43. The Construction Stormwater
Program

44. Construction Activity Threats
• Two-fold – construction projects have the
potential to cause impacts to our beneficial
uses of water both during and after the
project.
• During – potential for sediment erosion
discharges.
• After – potential for pollutant export and
hydromodification impacts as a result of how
the new landscape functions.

45. +
+
=Construction
WQ threats

46. Who needs coverage
1) All sites that disturb more than one
acre
2) All sites that are less than one acre but
part of a “larger plan of development”
3) All sites that are thought to be a
threat to water quality, as deemed by
the appropriate RWQCB

47. Permit Reissuance Goals
1) Adopt a risk-based permit approach-
“not all sites are created equal”
2) Improve “performance” measurement
of program
3) Establish standards to avoid, minimize
and mitigate post-construction impacts
associated with all new and re-
development projects triggering the
construction activity permit

48. Program “Performance” Elements
• Certification and training expectations
• Effluent monitoring = feedback for site
amd program
• Receiving water monitoring = feedback
for “water quality outcome”
goals/objectives
• Performance-based post-construction
runoff standards (pre = post)

49. Risk Approach
• Three risk categories
• Aimed at sediment transport and
receiving water risk of construction
activities “normal distribution”
assumption (most projects should not be
high risk)
• Incentives/requirements linked to risk.

50. Direct Erosion / Sediment
Control Requirements
• Old model used SWPPP as main vehicle
• New approach to use Rain Event Action
Plan (REAP) as primary tool (SWPPP
becomes more a master
document/library)
• Requirements based on risk
• Prevention and planning incentives

51. Post-Construction Impacts

52. Post-Construction Standards
• Design to mimic pre-development water
balance
• Preserve existing time of concentration
• Protect channels

55. After Lane (1955) as cited in Rosgen (1996)

56. Channel Changes Associated with Urbanization

57. The future
• Low Impact Development (LID) and
Green Infrastructure (GI)
represent “natural systems”
approach to building better urban
landscapes.
• Both aim to protect and/or restore
“natural hydrology” and ecological
processes
• LID – site and neighborhood scale
• GI – community and watershed scale

58. Ways to mimic pre-development water
balance and Tc

Soil quality improvement (porosity)

Native and drought tolerant
vegetation

Trees

Permeable pavement

Riparian buffers

A general reduction of connected,
impervious surfaces in runoff
pathways

Bioretention

Disconnected downspouts/rain
chains/rain barrels

59. Ideal Soil Structure for Plant Growth
Mineral
45%
Organic
Matter
5%
Water
25%
Air
25%

62. Rain chains and
mulch combo
Sacramento

72. Greg Gearheart
916.341.5892
ggearheart@waterboards.ca.gov