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Document Code No.: PUT 8-16 (PR)
Department/Issuing Agency: Department of Natural Resources/Industrial Waste Program
Effective Date: February 12, 1999
Approved: /s/ Ron Sims
Type of Action: Revised (reissued to incorporate agency name change due to reorganization of rule originally issued on October 1, 1995).

Signed document (PDF, 818 KB)

1.0 SUBJECT TITLE: Discharge of Cooling Water into Sanitary Sewer


2.1 To establish rules governing the discharge of cooling waters into the metropolitan sewer system.


3.1 Any person, as that term is defined in K.C.C. 28.82.600, that contributed cooling water from a facility that is not a residential dwelling unit.

3.2 King County Department of Natural Resources; Wastewater Treatment Division; Water and Land Resources Division; Industrial Waste Program.


4.1 K.C.C. 28.84.060 D.5.K. - Discharge Standards and Limitations (Specific Prohibitions for Discharges of Clean Water).

4.2 King County Ordinance No. 11034 - Establishes the Fees, Rules, and Regulations for the Disposal of Industrial Wastes into the Metropolitan Sewerage System.

The King County Code may be accessed on-line at: Laws of Washington may be accessed on-line at: The federal register and regulations may be accessed on-line at:


5.1 "Cooling water" shall mean the water discharged from any use, such as air conditioning, cooling, or refrigeration, or to which the only pollutant added is heat.

5.2 "Facility" is any building that either has its own heating and/or cooling system or cluster of buildings that share a common heating and/or cooling system.

5.3 "Reclamation Cooling Systems" are systems that use reclaimed water from any source.

5.4 "Recycling or Recirculating Cooling Systems" are systems that recycle or recirculate and do not have to discharge except for maintenance, cleaning, and blowdown.

5.5 "Reuse Cooling Systems" are systems that reuse water at least once or that use water from another source, e.g. process water used for cooling water.

5.6 "Single Pass Cooling Systems" are systems that use water once and then dispose of the water.


6.1 It is the policy of King County to provide sewerage facilities adequate for the transportation, treatment, and disposal of industrial and other wastes and to operate the metropolitan sewerage system in such a manner that protects public health and the environment. In carrying out this policy, the objectives of this rule are:
6.1.1 To prevent pollutants from entering the sewerage system that will interfere with its normal operation, damage the collection or treatment systems, or contaminate the resulting biosolids;

6.1.2 To prevent the introduction of pollutants into the sewerage system that will not be adequately treated and will pass through into the environment;

6.1.3 To improve opportunities for recycling and reclamation of wastewater and biosolids:

6.1.4 To ensure protection of worker safety and health;

6.1.5 To implement waste reduction and recycling to prolong the useful life of existing and planned wastewater facilities and to protect the environment;

6.1.6 To focus sampling and inspection efforts on those industries discharging the greatest volume and concentration of pollutants while still recognizing the cumulative impact of small discharges; and

6.1.7 To implement an enforcement response plan aimed at achieving compliance in the shortest time frame possible and promoting responsibility of the industrial user to be in compliance.

6.2 King County shall not restrict the discharge of cooling water. Instead, it will cooperate with the local water suppliers in conservation education programs to reduce cooling water usage and encourage the installation of reclamation, Recycling/Recirculating, and Reuse Cooling Systems.

6.3 King County will collaborate with local and state agencies to assess whether or not revisions to building code requirements to restrict single pass cooling water systems are feasible.




8.1 Dischargers of cooling water are responsible for ensuring that cooling water discharged to the sewer system meets the requirement of K.C.C. 28.84.060 (Ordinance No. 11034).

8.2 The King County Department of Natural Resources, Industrial Waste Program, is responsible for the enforcement of this public rule.