California State Stormwater Permit Requirements

CALIFORNIA STORMWATER

PERMIT REQUIREMENTS

Michael Josselyn, PhD PWSWRA, Inc.

November 2009

PURPOSE OF PRESENTATION

How is stormwater regulated in California?



What require-ments have been set by state government?



What require-ments have been set by state government?

How are these regulations implemented?

WATER QUALITY REGULATIONS

Regional

State

FederalClean Water Act

Delegation to State through federal law

NPDES Storm Water Management

401 Water Quality

Certification

Porter-Cologne Act

Water Quality Control Plans

FEDERAL: CLEAN WATER ACT Enacted in 1972 to protect nation’s water

quality Act prohibits the discharge of pollutants

from a point source into “waters of the United States”Unless a permit is obtained by the discharger

Environmental Protection Agency is given power to issue and enforce regulations

Permit program has been delegated to the State of California—NPDES permits

States also given power to approve wetland fill

STORMWATER REGULATIONS

Regional

State




401 Water Quality

Certification

Porter-Cologne Act


LEGAL ACTIONS MODIFY CWA Congress issues Clean Water Act

1972EPA decides not to regulate stormwater due

to problems inherent in regulating many outfalls

Environmental organizations win law suits to have stormwater regulated under NPDES

Congress amends Clean Water Act 1987 Industrial stormwater discharges

regulated EPA considers construction

activities to be industrial actions1990 EPA mandated that construction

activities be regulated under NPDES permits

STATE OF CALIFORNIA State Water Resources Control Board is

responsible for overall water management in the state

Defines stormwater as a “pollutant” and as a “point source” Subject to permitting under NPDES

regulations One source of stormwater

is from construction sites September 2009: New regulations

for construction activities

REGIONAL AUTHORITY State divided into

regions based on watershed boundaries

Each region responsible for separate “basin plans”Regulate water quality

to ensure beneficial uses of the streams and lakes in its region

CALIFORNIA CONSTRUCTION GENERAL STORMWATER PERMITEstablished by State Water Resources Control Board

September 2, 2009

WHY FOCUS ON CONSTRUCTION SITES?

20 to 1000 times more sediment from construction sitesTurbidity

increasesNutrient input

higherSediment buildup

in storm drainage devices

GENERAL PERMIT: CONSTRUCTION SITES Covers earth moving activities >

4000 sq m Regulates the amount of sediment

that can be discharged from construction sites

Sets standards for the discharge of certain pollutantsTurbidity and pHEstablishes a “design storm criteria”

Sets forth requirements related to risk level

Requires submission of Storm Water Quality Pollution Prevention Plan (SWPPP)

ESTABLISHES RISK LEVELS Increasing level of protection

Sediment Risk = Type of activity and location of activity

Receiving Water Risk = “Sediment sensitivity” of water body

SEDIMENT RISK Based on soil erosion factor

Calculated using Revised Universal Soil Loss Equation (RUSLE)

Considers Rainfall Soil Erodibility Length-slope factor Cover factor Sediment controls

REVISED UNIVERSAL SOIL LOSS EQUATION

A = R * K * LS * C * PA = the rate of sheet and rill erosion


A = R * K * LS * C * PA = the rate of sheet and rill erosionR = rainfall-runoff erosivity factor


A = R * K * LS * C * PA = the rate of sheet and rill erosionR = rainfall-runoff erosivity factorK = soil erodibility factorLS = length-slope factor

K/ LS Factor map for California


A = R * K * LS * C * PA = the rate of sheet and rill erosionR = rainfall-runoff erosivity factorK = soil erodibility factorLS = length-slope factorC = Cover FactorP = Protection Measures employed


A = R * K * LSA = the rate of sheet and rill erosionR = rainfall-runoff erosivity factorK = soil erodibility factorLS = length-slope factorC = Cover Factor = 1 for risk assessmentP = Protection Measures employed = 1

SEDIMENT LOSS RISK FACTORS

Soil loss (tons/ac)

Risk Level

Less than 15 Low15 to 75 MediumOver 75 High

Determine Value of A and relate risk below

RECEIVING WATER RISK Most sensitivity

to sedimentationFish spawning

areasFish migration

areasAny impaired

water body for sediment

HIGH RISK = MORE CONTROLS Use Standard Construction BMPs

Silt fences, hay bales, temporary detention Additional Factors to be added

Ensure soil loss during each phase does not exceed preconstruction soil loss

More frequent inspectionsDevelop Rain Event Action Plans to prepare

site within 48 hours in advance of rain events

Must meet numeric standards for Turbidity and pH

Establishes both action and limitation values

NUMERIC LIMITS Turbidity

Action level = 250 NTULimit level = 500 NTU

Exceed Action Levels Improve BMPs and implement corrective

actions Exceed Limit Levels

Additional monitoring and possible fines

pHAction level = 6.5-

8.5 Limit level = 6.0 –

9.0

TURBIDITY MEASUREMENT

MINIMIZE HYDROMODIFICATION Runoff Project Water Flow

Pre Project Flows = Post Project FlowsUp to the 85th percentile storm event

Must consider both construction and post project featuresUse of detention basinsUse of LID featuresMaintaining natural vegetation and stream

configurations within projects

MUST SUBMIT STORMWATER PLAN:SWPPP Must be prepared by a qualified

individual Evaluates Risk Factors Describes all the best management

practices Describes compliance

plan Provides for monitor-

ing and reporting

WATERSHED REGULATIONS

Wetland and Stream Protection

WATER QUALITY REGULATIONS

Regional

State




401 Water Quality

Certification

Porter-Cologne Act


WETLAND AND STREAM FILL PROTECTIONS

401 Water Quality Certification


401 Water Quality Certification

Must approve loss of wetlands and streams in watersheds regulated by federal government

Must try to avoid and minimize impacts

Fill must be accompanied by wetland and stream replacement Usually 2 to 3 times as

much land as filled


401 Water Quality Certification Porter Cologne Act




much land as filled


401 Water Quality Certification Porter Cologne Act




much land as filled

Regulates fill placement in wetlands and streams

Cannot result in decreased beneficial uses Fish habitat Human use and

health Water quality

WATERSHED LEVEL REGULATION

No net loss of wetland and stream habitat

Requires that any loss be “mitigated”

Replacement areas must be in same watershed

MITIGATION POLICIES Must create new wetlands and streams

in greater quantity than lost—”Mitigation Ratio”

Wetlands and stream creation must maintain or reduce hydromodification

Wetland must be created similar to that which is lost

Performance standards must be met over 5 year monitoring program

WETLAND MITIGATION AREAS

Freshwater marsh Riparian and Meadow Habitat

ALSO APPLIES TO TIDAL AREAS

Batiquitos Lagoon Channel Construction

WETLAND CREATION TECHNOLOGY

Has expanded significantly over past 20 years

Many wetland types Freshwater marsh Riparian habitat Vernal pools Streams

New policies in effect to improve science and performance

MITIGATION BANKS Established by private companies Determine areas where development is

occurring Create wetland and stream habitat

May include habitat for unique plants and animals

Sell credits on the open market to private parties and governmental agencies

Must maintain these areas in perpetuity

SUMMARY OF STATE REGULATIONS Strictly regulates construction activities Sets methods to evaluate risk levels

associated with various activities Establishes numeric standards for some

attributes Seeks to control hydromodification

Incorporate features in project design to control flow

Regulates stream and wetland fill Requires habitat replacement through

mitigation Sets standards for reporting and monitoring

California State Stormwater Permit Requirements

Real Estate

Transcript of California State Stormwater Permit Requirements