Background

Mark III designs commercial buildings in Northern California, including areas in and around Sacramento County. Citizens and SoCal Water (dba Arden-Cordova Water Company) provide Commission-regulated water utility service to some of those areas.

Mark III alleges, and both Defendants acknowledge, that Defendants' routine practice is to require approved backflow prevention assemblies be installed at the service connections for all new commercial buildings having Class 1 or Class 2 fire sprinkler systems.

Backflow is the undesirable reversal of flow into a potable water distribution system. A cross-connection is an unprotected actual or potential connection between a potable water system used to supply water for drinking purposes and any source or system containing unapproved water or a substance that is not or cannot be approved as safe, wholesome, and potable.¹ When the pressure in the supply side of a potable water supply system is lower than the pressure somewhere else such that water could flow backward into the supply line, a cross-connection is said to exist and there is a potential for the system to become contaminated.

One method to prevent backflow into a water system is to install one-way valve arrangements or disconnects between the supply line and the potential source of backflowing water. Modern water distribution technology includes a variety of cross-connection and backflow prevention devices and assemblies that serve just that purpose. In some cases, there are tradeoffs in installing backflow prevention devices, including additional cost and reduction in water pressure.

Mark III designs fire sprinkler systems to be incorporated into the buildings it constructs. Defendants have concluded that the water in all fire sprinkler systems may over time become stagnant and a source of backflow contamination to the potable water supply system. Thus, they require all service connections to premises which have fire sprinkler systems to have approved backflow prevention devices installed and maintained at the user's expense regardless of the circumstances of the particular location.^{2 3}

Class 1 automatic fire sprinkler systems are those with direct connection from public water mains only; no pumps, tanks, or reservoirs; no physical connection from other water supplies; no anti-freeze or additives of any kind; and all sprinkler drains discharging to the atmosphere or other safe outlets. Class 2 sprinkler systems are the same as Class 1 except that booster pumps may be installed in the connections from the street mains.⁴ There are additional fire protection system classes, but they are not at issue here.

Mark III points to the straightforward language of H&SC Section 13114.7(b), which provides,

[Class 1 and Class 2] automatic fire sprinkler systems... shall not require any backflow protection equipment at the service connection other than required by standards for those systems contained in the publication of the National Fire Protection Association entitled "Installation of Sprinkler Systems"....

Thus, according to Mark III, Defendants' practice requiring it to include approved backflow protection devices at all new water service connections for Class 1 and Class 2 fire protection systems on all projects planned by Mark III in Defendants' service territories is unnecessary and unlawful when applied routinely to its projects without consideration of the conditions specific to each site.

Both Defendants maintain their practice is appropriate and required by law. More specifically, the requirement arises variously from the provisions of Commission General Order (GO) 103; CCR, Title 17, Sections 7583 through 7605; the Sacramento County Plumbing Code and the City of Sacramento's cross-connection policy; the State Fire Marshal's and Department of Health Services' (DHS) joint Information Bulletin on Cross-Connection Control Requirements; an American Water Works Association Research Foundation (AWWARF) research report; and each utility's Tariff Rule 16. Both Defendants summon largely the same arguments and references in their defense, and in any case endorse one-another's positions, so the discussion here will not attempt to distinguish between them except where the differences are significant.

Assigned Administrative Law Judge McVicar was designated as the presiding officer for this adjudicatory proceeding. A prehearing conference was held on August 7, 2000, and one day of evidentiary hearing on September 27, 2000. The proceeding was submitted on concurrent briefs due November 6, 2000.