Discharging Chlorinated Water

Discharges of chlorinated water to the storm drain system, which leads directly to local streams, can have detrimental impacts to our local streams. Chlorine and chloramines are toxic to fish and other aquatic life. To safeguard against adverse effects to the environment, the County has developed dechlorination and disposal procedures that must be taken when draining or discharging chlorinated water.

Requirements

  • Contractors are responsible for proper dechlorination of water prior to draining and discharging potable water to the storm drain system.
  • Contractors must comply with the Department of Environmental Services construction standards and specifications Section 02550 – 3.4 L (Discharge of chlorinated water).
  • Contractors must sign and submit a dechlorination policy acknowledgement form to the Water, Sewer, Streets Bureau.
  • Highly chlorinated water (water with chlorine levels greater than potable water used for disinfection purposes) must be discharged to the sanitary sewer system. Discharges of highly chlorinated water require a dechlorination plan that must be submitted to and approved by the Water, Sewers, Streets Bureau prior to commencing any discharge. The plan includes information on how and where the highly chlorinated water will be discharged. The plan also requires a signed acknowledgement that the  Contractor understands and will comply with the County’s standards and dechlorination and disposal procedures. Work may not commence until the dechlorination plan and signed acknowledgement has been approved by the County.
  • Contractors need to provide advanced notice prior to discharging highly chlorinated water to the sanitary sewer system. County staff must be present to observe the discharge operation.

Enforcement action may be taken against responsible parties that fail to comply with these procedures  and cause an unauthorized non-stormwater discharge to the County’s storm drain system and/or streams. 

These requirements don’t apply to emergency situations and unavoidable discharges of potable water such as flows from firefighting activities and water main breaks.