Cross connections between a water supply and non-potable source of contamination represents one of the most significant threats to health in the water supply industry. Cross connections may occur when the water pressure within the water system drops below the pressure within the customers plumbing and the customer's plumbing is connected to a contaminated source. The resulting back-flow could contaminate the water supply unless proper protections are in place.

Example: A customer is filling a metal tub with water through a garden hose. The metal tub also contains a stripping solution and the district experience a water main break that lowers the water pressure in the water system. The mixture within the metal tub will Flow Back into the water main and contaminate the public water system. The pressure within the water system may also drop due to fire hydrant usage or high usage by customers at a lower elevation than the source of contamination.

There are several types of devices available that will protect the public water system from cross connections. When a device is installed on the customers plumbing directly after the water meter, it will prevent all the water within the customers piping from entering the public water system. This type of installation is called containment, and the device is called a Back Flow Preventer.

Back flow preventers are available in three categories:

1) Dual check valve

2) Testable double check valve

3) Reduced pressure principle back flow preventer (RPZ)
 

The district has adopted a set of CROSS CONNECTION RULES AND REGULATIONS that are designed to protect our customers from this potential threat. Any interested person who wishes to read these rules and regulations may visit the district office during normal business hours. A fee shall apply if a copy is desired.

The following is a brief summary of the minimum requirements for each customer.

DESCRIPTION DEVICE REQUIRED

Multi - dwelling unit buildings with a single meter:

2 - 4 units Dual check valve

5 - 9 units Testable double check valve

10 or more units RPZ

Commercial preparation of food Testable double check valve

Businesses that utilize petroleum based products RPZ

Schools Testable double check valve

Single family residential****** Dual check valve

*****When the district replaces a water meter for maintenance purposes, the district will install a dual check valve for a single family residential customer at the customer's expense. The customer will be billed $25.00 for this service.

A back flow device will be required on all projects, whereby the company is required to remove and reinstall a meter.

A back flow device will be required on all projects, whereby the company is required to disconnect the water to facilitate inside plumbing projects or when an existing water service line is renewed.

All new water services will be required to have a back flow preventer before any water will be provided.