Development >> Construction Site Runoff Control
Construction Site Runoff Control
It's the Law!
There are two NPDES permits that regulate polluted runoff from construction sites.
NPDES Construction General Permit
Any person or agency whose project disturbs 1 or more acres of soil or whose project disturbs less than 1 acre but are part of a larger common plan of development that in total disturbs 1 or more acres, are required to obtain coverage under the General Permit for Discharges of Storm Water Associated with Construction Activity. Construction activity subject to this permit includes clearing, grading and disturbances to the ground such as stockpiling, or excavation, but does not include regular maintenance activities performed to restore the original line, grade, or capacity of the facility.
You can learn more about the general permit at the State Water Resources Control Board's website (www.swrcb.ca.gov/stormwtr/construction.html).
NPDES Municipal General Permit
All of the incorporated and unincorporated areas within the Napa River watershed are covered under the Phase II NPDES Municipal General Permit. Under this permit, the NCSWMP partners are required to develop, implement, and enforce a program to reduce pollutants from constuction sites greater than 1 acre. This program must include the following:
- legal authority to establish BMP requirements
- procedures for site plan review
- procedures for receiving complaints from the public
- procedures for inspection and enforcement
Even if your construction site is under 1 acre, the NCWMP partners are still responsible for any illicit discharges to the stormwater conveyance system. For this reason, your project may still be required to prepare a plan to prevent illicit discharges and may be inspected for compliance with the discharge prohibitions in the local stormwater ordianance.
You can learn more about the local requirements for each of the NCSWMP partners as well as the use of BMPs to control pollution from construction sites in the menu on the left.