Local rules guide
Draining a Pool in Contra Costa County
In Contra Costa County, pool, spa and fountain water may not go into the street or storm drain. Drain it to the sanitary sewer cleanout instead, after getting a discharge permit from Central San, which asks for 48 hours’ notice (Central San). Central San doesn’t charge for the permit.
Talk it through first
(925) 574-5921Resurfacing or remodeling? The pool contractor usually handles the drain permit and pumping. Ask when you call.
Request a QuoteThe rule
Why the storm drain is off-limits
Storm drains flow to creeks, the Delta and the Bay without treatment. The Contra Costa Clean Water Program says draining pools to storm drains can pollute those waters with copper, chlorine, sediment and other contaminants, and that pools should be discharged only to the sanitary sewer with permission from the local wastewater agency (Clean Water Program brochure).
How to
Central San permit steps
- Check your sewer agencyCentral San serves Walnut Creek, Lafayette, Orinda, Moraga, Danville, Alamo and much of central Contra Costa. If your sewer bill comes from another agency, ask that agency instead.
- Find your sewer cleanoutThe cleanout is usually a capped pipe near the house, on the sewer lateral. Pool water is pumped into it, never into a yard drain or gutter.
- Note the water detailsThe application asks about the water: salt content, solids, pH and whether copper is present (Central San).
- Apply online, 48 hours aheadApply on Central San’s pool discharge page (poolapp.centralsan.org) at least 48 hours before the drain date.
- Drain at a controlled ratePump slowly enough that the lateral does not back up. Stop if the cleanout overflows.
Practical
Why pool pros usually handle draining
- They pull the permit and time the drain to the day the crew starts.
- An empty pool shell is vulnerable to groundwater pressure; pros judge how long a pool can safely sit empty.
- Plaster work starts as soon as the pool is empty, and refilling starts the same day the finish goes on.
- Pumping equipment sized for the job keeps the drain rate within what the lateral can take.
Draining comes up most for resurfacing and remodels. Leak testing is normally done with the pool full.
Answers
Questions people ask
Can I drain my pool onto my lawn?
Large volumes of pool water can run off a lawn into the street and storm drain. Central San and the Clean Water Program direct pool water to the sanitary sewer with a permit.
Does the Central San permit cost anything?
No. Central San describes the pool, spa or fountain discharge permit as free and easy to get, with 48 hours’ notice.
How often should a pool be drained?
Only when work requires it, such as resurfacing, or when a pro advises it for water quality. Draining wastes water and stresses the shell.
Keep going
Related repairs and guides
Next step
Tell a local pool pro what the pool is doing
Share the symptoms, the pool type and your city. A local pool repair contractor can follow up with questions, next steps and pricing.
- Resurfacing, leaks, equipment, tile and remodels
- Walnut Creek, Danville, Alamo, Lafayette and nearby
- Ask for a written scope before any work starts
Prefer to talk? (925) 574-5921