Heights Water

Business Office. Parker Plaza | 17232 Vashon Hwy. SW | P.O. Box 820 | Vashon, WA 98070   Tel. 206-463-0014   Email. info@heightswater.org






Mailing address

PO Box 820

Vashon, WA 98070


Business Office

17232 Vashon Highway SW

p 206-463-0014

M-F 10:00 a.m. - 3:00 p.m.


Pumping Station

13205 Vashon Highway SW


A private non profit mutual water association serving the north end of Vashon Island

Backflow Prevention Information

Cross Connection Control


Cross-connection is defined by the Washington Administrative Code (WAC) as "any actual or potential physical connection between potable water and any pipe, vessel, or machine that contains or has a probability of containing a non-potable gas or liquid, such that it is possible for a non-potable gas or liquid to enter the potable water system by backflow."


Heights Water's cross-connection control program helps protect public health by preventing contamination of the drinking water as it is delivered to water system customers. Washington State drinking water regulation, WAC 246-290-490, requires each public water system to develop and implement a cross-connection control program.


For most residential customers, the cross-connection control hazard posed to the public water system is minimal if the plumbing was installed in compliance with the Uniform Plumbing Code. The Uniform Plumbing Code generally provides adequate protection of our water, potable water piping, and our public water distribution system from cross-connections. However, customers with special plumbing or activities on their premises may pose an increased health risk to other customers served by our system. These customers may need to have a backflow preventer installed on their service lines or provide alternate protection to prevent contamination of the public water system.


As part of our efforts to keep the drinking water safe, Heights Water periodically conducts a hazard survey of customers served by our system. The survey helps us determine if any of our customers have special plumbing or activities on their premises that could increase the risk of contamination to our water system.


For further information about the cross-connection control program, please contact the Heights Water business office at 206-463-0014.