Construction Stormwater Rules-2012

Rodney Hendrick, Ph. D.Louisiana Urban Stormwater

Coalition

Clean Water Act

• Passed by Congress in 1972• Goal was to make the waters of the US fishable,

swimmable and drinkable.• Originally thought that treating waste water and

other point sources could accomplish goal• Act contained authority to set limits on non-point

runoff if necessary.• Called for survey of streams to determine their

condition.

TMDLS

• Sets allowable loads of pollutants that a stream can accommodate and still meet usage

• Influenced by stream volume, current flow, topography, stream bottom, sources of flow and type of loadings.

• Natural loads can reduce the amount of man made loadings a stream can handle.

• Many Louisiana streams have low flow rates, muddy bottoms and high natural loads.

Stormwater Management Programs

• Industrial-Used to control and clean up rainwater discharges from industry and some businesses.

• Urban-Requires stormwater management programs from urbanized areas.

• Construction-Requires Permits and stormwater management plans from construction sites with overall plans for 1 acre or more.

Stormwater Management

• Authorized in 1990 and permits issued in early ‘90s for Industries, Large Urban Areas (100,000+) and Construction Sites of 5 Acres or more.

• Small Urban Areas (10,000) and Small Construction Site (1 Acre or more) Programs began in 2003.

Urban Stormwater

• The Large and Small Urban Stormwater Permit holders, also known as MS4s (Municipal Separate Storm Sewer Systems) are required to conduct programs in certain areas including enforcing the Construction and Post-Construction Regulations.

• As part of their permit requirements the MS4s are to design and implement programs to meet the load reduction requirements of any TMDL on their stormwater receiving streams.

Impaired Waters

• A large number of Louisiana streams are classified as impaired and many have or will have TMDLs.

• The most common listed reason is low Dissolved Oxygen (DO).

• Sediment, organic matter and nutrients are the principal man made input loads causing this condition.

Impairment Status of Louisiana’s Basin Sub-

segments

Construction

• Construction and land clearing often expose freshly disturbed soil to rain and wind for erosion.

• The soil loss per acre in construction is generally many times the loss in agriculture.

• Much of this loss is preventable.• In addition to soil, runoff from construction sites

can carry other pollutants along with the soil.

Construction Stormwater Management

• Before beginning any soil disturbance two things are required;– Development of a Stormwater Pollution

Prevention Plan (SWPPP)– Filing a Notice of Intent with DEQ (waived for

Small Construction Sites)– If the site is in a MS4 they will probably want to

see the SWPPP when you go for a building permit.

Eligibility

• The construction will disturb 1 or more acres or is part of a development that is 1 acre or more.

• You are an operator in control of the site in whole or in part.

• You will not endanger threatened or endangered species or their habitat.

• The project will not damage historic places.

Eligibility

• The discharge will not cause an excursion of any water quality standard.

• The discharge will not lower the water quality in any High Water Quality stream.

• Only Stormwater discharges or approved non-stormwater discharges are covered by the permit.

• You must design, install and maintain adequate erosion and sediment controls.

Erosion and Sediment Control

• Minimize area of disturbed soil and length of disturbance.

• In the SWPPP design you must account for the amount , frequency, intensity, and duration of the rain.

• Run-on to site and runoff from impervious surfaces, slopes and drainage features.

• You must accommodate peak flow rates and total stormwater volume.

Erosion and Sediment Control

• You must account for the range of soil particle sizes at the site, both native and fill dirt.

• Direct discharges to vegetated areas.• Install and make operational stormwater

controls before beginning each phase of soil disturbance.

• Provide or maintain 50-foot natural buffer or equivalent if within 50-foot of a surface water.

Erosion and Sediment Control

• Install perimeter controls• Minimize Sediment Track-out• Control Discharges from Soil Stockpiles• Minimize Dust• Minimize Disturbance of Steep Slopes• Preserve Topsoil• Minimize Soil Compaction• Protect Storm Drains

Erosion and Sediment Control

• Constructed Stormwater Conveyance Channel-avoid un-stabilized areas, minimize erosion of channels, banks and use velocity dissipating devices

• Sediment Basins-must accommodate a 2 year 24 hour rain event or 3,600 cubic feet per acre; prevent erosion of banks and bottoms, and be locate outside of surface waters. Maintain volume by sediment removal.

Site Stabilization

• Must begin when earth disturbing activities have permanently or temporally ceased on any portion of site. Must be complete in 14 days after initiated.

• If you are discharging to a sensitive or impaired water the stabilization must be complete in 7 days.

Pollution Prevention

• You must design, install and maintain effective pollution prevention measures.

• You cannot discharge washout water from concrete unless properly treated.

• Wastewater from washout of paint, stucco form release or other chemical unless properly treated.

• Fuels, oils or other pollutants used in vehicles.• Soaps, solvents, detergents or toxic materials.

Pollution Prevention

• Ensure that all Pollution Prevention controls remain effective and inspect with regular inspections.

• Clean up spills immediately and repair or replace non-functioning controls in 7 days. Record in inspection report and modify SWPPP as needed. Use dry clean up materials and properly dispose of clean up material.

Storage

• Construction materials, pesticides, petroleum products, soaps, detergents, paint, solvents, hazardous, and toxic materials and their wastes must be stored under roof or plastic in sealed containers.

• Construction waste must be cleaned up each day and stored in containers or dumpsters.

• Port-a-Potties must be placed where they are secure and will not be tipped over.

Water Discharges

• Must not impair water quality in receiving stream

• For Impaired receiving streams impaired for sediment or sediment related parameters or for nutrients then you must:– List all impaired streams your discharge will reach– List the pollutants for which the streams are listed– Identify if a TMDL is approved or established

Discharges to Impaired Waters

• Inspect every 7 days and• Within 24 hours of a rain event of 0.25 inches• Record the total rainfall for the day• Inspect all disturbed areas all BMPs and all

discharge areas• Prepare a signed Inspection report within 24

hours

Corrective Actions

• Must begin immediately and be complete in 7 calendar days

• If changes to controls are necessary, then change the SWPPP with 7 days of completion

• Do corrective action report

Staff Training

• The following personnel must be trained on the permit and their responsibilities.

• Design, installation, maintenance and repair of control measures

• Inspectors and those responsible for taking corrective actions

• All personnel should know location of protective measures on site

The SWPPP

• Must include the Stormwater Team• Nature of construction activities• List of all other operators on site• Sequence and estimated dates of activities• Site maps• List of pollutant generating activities on site• Non-stormwater discharges• Buffer Documentation

The SWPPP

• Description of Stormwater Control Measures• Any use of Treatment Chemicals and list of all soil

types and chemicals to be used• Stabilization practices to be used• Pollution Prevention Procedures• Waste Management Procedures• Procedures for inspections, maintenance and

corrective action• Staff Training

The SWPPP

• Documentation of Compliance with Endangered Species Act, Historic Properties protection and Safe Drinking Water Act Underground Injection Control

• The SWPPP must be signed and on-site• Must contain a copy of the NOI and

acceptance• A copy of this Permit

Notice of Termination

• All disturbed areas are stabilized that are not covered by structures

• All construction materials, waste and equipment has been removed

• All non permanent stormwater controls have been removed or

• Control has been transferred and new NOI approved or a separate LPDES permit issued

The Louisiana Urban Stormwater Coalition

http://louisianastormwater.org/