Stormwater Management: Carson vs Santa Clarita

Can I wash my car in my Carson driveway?

Residential car washing where soap runs into the street/storm drain is technically a prohibited non-stormwater discharge under CMC Art. 4 Ch. 8. The city generally focuses enforcement on commercial car washes and industrial discharges, but residents are encouraged to wash on lawn/gravel or use a commercial wash that routes water to the sanitary sewer.

Do I need a stormwater permit for a small home addition?

Projects disturbing less than 1 acre typically don't trigger the state Construction General Permit, but Carson still requires erosion and sediment controls during construction under the local ordinance and the LA County MS4 permit. Larger redevelopment projects (varies by use; 5,000-10,000 sq ft impervious is a common LA County threshold) trigger Low Impact Development post-construction BMPs.

Who enforces stormwater rules at the Carson refineries?

Industrial facilities like the Marathon and Phillips 66 refineries are covered by the State Water Board's Industrial General Permit (Order 2014-0057-DWQ) and discharge under individual NPDES permits — primary enforcement is the LA Regional Water Quality Control Board, not the City of Carson, though city code enforcement can act on illicit discharges entering the MS4.

Do I need a stormwater plan for my project?

Generally required for new construction and major renovations that increase impervious surface area. Small residential projects may be exempt.

What is an illicit discharge?

Any non-stormwater substance entering the storm drain system, including paint, oil, chemicals, or sediment. Report violations to Santa Clarita public works.