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Needed Improvements to UPC Greywater Law

Summary: California's new greywater law is an important step and certainly as well done as was politically possible. However, it's a step not quite in the right direction, which is unfortunate as it is being emulated all over the US and the world.
Here's a list of needed improvements, excerpted from our book the Builder's Greywater Guide, which also includes the full text of the law with annotations directly in the text describing the implications of each section.
Please help distribute this information as widely as possible.


California is about to revise their greywater law as a consequence of the recent passage of Assembly Bill 313. This is an important opportunity to update this groundbreaking legislation. The current law, by mandating design specifics which eliminate every theoretical vestige of risk in every scenario, has greatly increased the public health threat from greywater systems. Santa Barbara, for example has issued approximately 10 permits for greywater systems since greywater was legalized in 1989b12. This is in an area with 200,000 people, as many as 40% of whom were using greywater in the last drought!b13 So many requirements are obviously overkill that the entire law, including some very sensible provisions, is dismissed as a source of design guidance. A more reasonable regulatory stance would lead to greater participation and a reduction in risk from the perpetuation of unregulated systems. As California's law is being taken as a model for other states and countries this is all the more vital.

Direct your comments to the State Department of Water Resources-and be nice. These people have worked very hard to get this law in place against considerable resistance.

In general

Take a tiered approach to regulating greywater like Arizona and New Mexico, with no permit application required for first tier, small residential systems that meet a list of requirements.

Wherever appropriate, require achievement of goals (e.g., ecologically and biologically safe treatment of wastewater), with explicit designs as options, rather than specifying mandatory techniques to be used.

Be more realistic about the quantitative health threat from greywater systems. There is a long history of surface greywater reuse (with systems far, far less safe than those specified in the current law) which has not produced a single documented case of greywater-transmitted illness in the United States.

In Australia greywater is legally distributed through sprinklers with 6 foot throw. The City of Los Angeles Greywater Pilot Project showed that dog feces were a far greater contributor to pathogens in soil than greywater irrigation. Even the worst illegal greywater systems don't stand out among myriad sources that besiege our bodies with pathogens in the course of ordinary life. The actual health threat is small enough to include ecological and practical considerations along with public heath considerations.

Consider exposure from required maintenance in comparing the relative health risk of systems.
Local jurisdictions should consider the effect of high permit fees on participation in the legal process. In our area a greywater permit costs $75, increasing the attractiveness of simple, illegal systems, which already have dramatically superior cost/benefit ratios to currently legal systems in most situations.

Change the Uniform Plumbing Code to require greywater and blackwater to be plumbed separately for all new construction of single family homes on 1/4 acre or more. The lines should be joined after all the fixtures and vents and at or after a convenient future greywater diversion point.

Specific suggestions

J-1-a Allow commercial and multifamily systems (this change is already approved). This is a serious problem with the current law.

J-1-f Allow reduction in size or elimination of septic/sewer system at the discretion of the Administrative Authority, if the alternative waste disposal system(s) are capable of handling all wastes as well or better. There are sites and regions where currently mandated treatment technologies cause more ecological and health problems than proven alternatives.

J-2 Redefine kitchen sink and dishwasher effluent as "difficult to handle greywater" (rather than blackwater) and allow its use the discretion of the Administrative Authority, if the hardware is demonstrably able to handle it. This high solids water is a (solvable) hardware design problem, not a soil or public health problem.

J-7 Allow greywater systems in areas with high groundwater at the discretion of the Administrative Authority (a proper greywater system design can provide better treatment and protect groundwater better than currently mandated systems).

J-7 Eliminate the requirement for two irrigation zones which are each capable of accepting the entire greywater flow, if there is a disposal alternative. This ill-thought through requirement eliminates the possibility of meeting all the irrigation needs of an area with greywater, whether it makes sense or not. It effectively mandates the installation of a redundant freshwater irrigation system, which would severely undermine the economics of some systems, particularly commercial or multifamily systems. High end greywater systems are capable of distributing freshwater as needed for supplemental irrigation without wasteful hardware duplication. This is a serious problem with the current law.

J-7, J-8, Table J-2, Table J-3 Explicitly allow reduction in system design loads with water conserving fixtures. The current language allows local discretion in this area but the possibility is not obvious.

J-8-b Allow greywater systems across a wider range of percolation rates. Greywater systems can be safer at percolation extremes than septic systems.

J-9-e Delete the requirement for a gravity drain for surge tanks. A gravity drain is a nice convenience but it is a practical impossibility for many installations. Note that current law does not require a gravity drain for underground greywater surge tanks, septic tanks, or sewage ejector pump tanks. This is a serious problem with the current law.

J-9-h Require below grade tanks to be anchored against popping to the surface if conditions indicate this may be a problem. Unlike septic tanks, greywater surge tanks are often empty and experience tremendous buoyant lift under saturated soil conditions.

J-11-a-2 Modify the requirement that "system design shall be such that emitter flow variation shall not exceed plus or minus 10%" with the phrase "in instances where greater variation could result in flows high enough to produce per emitter ponding in the soil in question."

J-11-a-6 Change wording from "pressure at pump shall not exceed 20 psi" to "pressure at any emission device not exceed 20 psi." The current wording effectively precludes irrigation with adequate pressure at a location significantly higher than the pump.

J-11-a-5, J-11-b-2 Explicitly allow greywater to be distributed and emitted through lines covered by mulch at the discretion of the Administrative Authority.

J-11-b-1 Allow smaller diameter pipes in mini-leachfields, allow half-pipes in mini-leachfields.
Table J-1 Allow installations on steeper slopes where environmental conditions are such that the water will not surface.

Explicitly describe "Infiltration beds," "Leaching Chambers," "Box Troughs," (see Create an Oasis with Greywater"), and "hard plumbing to mini-leachfields" (see pages 11-14) as allowed system examples.

Figures: Show a greywater surge tank rather than a sewage ejector pump tank in figures.

Allow the use of swing check valves instead of expensive backwater valves.

Allow greywater surge tank to be vented back through the house vents (as is done with all septic tanks and sewers) as an alternative to a vent at the tank.