27.14.110 Illicit discharges and connections.
(1) Illicit Discharges Prohibited. No person may throw, drain, or otherwise discharge, cause or allow others under their control to throw, drain, or otherwise discharge into the storm drain system, or into a watercourse within unincorporated Clallam County, any materials other than stormwater.
(2) Allowable Discharges. The following types of discharges are not illicit discharges for the purpose of this chapter unless the County Engineer, or their designee, determines that the type of discharge, whether singularly or in combination with others, is causing or is likely to cause pollution of surface water or groundwater:
(a) Diverted stream flows.
(b) Rising groundwaters.
(c) Uncontaminated groundwater infiltration as defined in 40 CFR 35.2005(20).
(d) Uncontaminated pumped groundwater.
(e) Foundation drains.
(f) Air conditioning condensation.
(g) Irrigation water from agricultural sources that is commingled with urban stormwater.
(h) Springs.
(i) Uncontaminated water from crawlspace pumps.
(j) Footing drains.
(k) Flows from riparian habitats and wetlands.
(l) Nonstormwater discharges authorized by another NPDES or state waste discharge permit.
(m) Discharges from emergency firefighting activities.
(3) Conditionally Allowed Discharges. The following types of discharges are not illicit discharges for the purposes of this chapter if they meet the stated conditions, unless the County Engineer, or their designee, determines that the type of discharge, whether singularly or in combination with others, is causing or is likely to cause pollution of surface water or groundwater:
(a) Potable water, including water from water line flushing, hyperchlorinated water line flushing, fire hydrant system flushing, and pipeline hydrostatic test water. Planned discharges must be dechlorinated to a concentration of 0.1 ppm or less, pH-adjusted, if necessary and in volumes and velocities controlled to prevent re-suspension of sediments in the stormwater system.
(b) Lawn watering and other irrigation runoff are permitted but must be minimized.
(c) Dechlorinated swimming pool, spa and hot tub discharges to surface waters. These discharges must be dechlorinated to a concentration of 0.1 ppm or less, pH-adjusted and re-oxygenated, if necessary and in volumes and velocities controlled to prevent resuspension of sediments in the stormwater system. Discharges must be thermally controlled to prevent an increase in temperature of the receiving water. Swimming pool cleaning wastewater and filter backwash shall not be discharged to the stormwater system.
(d) Street and sidewalk wash water, water to control dust and routine external building wash down that does not use detergents are permitted if the amount of street wash and dust control water is minimized. At active construction sites, street sweeping must be performed prior to washing the street.
(e) Other non-stormwater discharges. The discharges must be in compliance with the requirements of a stormwater pollution prevention plan (SWPPP) reviewed and approved by the County which addresses control of such discharges by applying all known, available and reasonable methods of prevention, control and treatment (AKART) to prevent pollutants from entering surface or groundwater.
(4) Illicit Connections.
(a) No person may use the stormwater system, directly or indirectly, to dispose of any solid or liquid matter other than stormwater.
(b) No person may make, use, or allow the continued existence of any connection to the stormwater system that could result in an illicit discharge.
(c) Connections to the stormwater system from the interiors of structures are prohibited.
(d) Sewer connections to the stormwater system or to any watercourse are prohibited.
(e) Connections to the stormwater system for any purpose other than to convey stormwater or groundwater are prohibited and must be eliminated.