Stormwater Management: Daly City vs South San Francisco

Can I wash my car in my driveway?

Wash water that runs to the street storm drain is a prohibited discharge under the MRP and SMCWPPP rules. Use a commercial car wash that recycles wash water, or wash on a vegetated/gravel area where soapy water soaks in instead of running to the gutter.

Do small home additions need stormwater treatment?

Residential projects that create or replace less than 10,000 sq ft of impervious surface are generally below the C.3 Regulated Project threshold, but construction-site BMPs (silt fence, covered material storage, no concrete washout into the gutter) are still required by the MRP and by Daly City's grading/erosion-control rules.

Can I drain my pool to the street?

Chlorinated, copper-treated, or salt pool water is a prohibited discharge. Dechlorinate, then discharge slowly to landscape, or coordinate with North San Mateo County Sanitation District for sanitary-sewer discharge — never to a storm drain inlet or gutter.

Does adding a patio or new driveway trigger stormwater treatment?

If your project creates or replaces 2,500 or more square feet of impervious surface (cumulative over 5 years), yes — you trigger Provision C.3 and must implement on-site stormwater treatment (typically a bioretention area sized to the project). Permeable pavers receive 50% credit. Below 2,500 sq ft, source control and site design still apply but full treatment is not required.

How do I report oil or paint being dumped down a storm drain?

Call the San Mateo County Stormwater Pollution Hotline: (650) 599-1420, or report online at smcsustainability.org/report-pollution. For immediate hazards (large spill, chemicals reaching a creek) call 911. Illicit discharges carry federal Clean Water Act penalties.