As summer winds down, many people drain their swimming pools to reduce maintenance and potential damage from freezing during winter. Many have questioned why pool water is not allowed to be discharged into out municipal storm sewer system. Chlorinated water has an adverse effect on local water quality. Aquatic life in our waterways is also threatened by copper used as algaecide in pools.
According to the Environmental Protection Agency (EPA) an average swimming pool holds 19,000 gallons of highly chlorinated water, which is toxic to wildlife and fish. Chlorine is especially harmful to organisms that reside in soil and water. It causes environmental harm at low levels. Once in the air or water, chlorine reacts with other chemicals. It can combine with inorganic material in water to form chloride salts, and with organic material in water to form chlorinated organic chemicals.
Instead of discharging pool water to the storm sewer system or directly into a water body; homeowners should consider the following advice from the City’s Storm Water Utility:
· Discharge water into a sanitary cleanout.
· If the only option is to discharge into the environment, water quality must be tested and comply with applicable water quality criteria:
o De-chlorinate the water before draining the pool.
§ Pool water must sit for at least 1 week after the addition of chlorine and bromine or until levels are below 0.1mg/L
o The pH of discharge water must be between 6.5 and 8.5
o Total suspended solids must be below 60 mg/L
o Discharge over a land surface so that some level of filtration by soil particles can occur.
As always, feel free to contact Derrick Byers of the Stormwater Utility for advice on all stormwater related issues.