Via Spouting Off, an interesting article on the Los Angeles County’s recently released rainwater harvesting guidelines:
L.A. County’s Department of Public Health has just released rainwater harvesting guidelines that help transform the region’s management of stormwater runoff. The guidelines apply to rainwater harvesting projects, including rain barrels and cisterns, and they significantly shift the approach from treating rainwater as a pollution source and flood control problem to managing it as a critical resource.
The guidelines were released at the site of a massive Proposition O project at Penmar Park in Venice. A giant pit and a huge dirt mound served as the backdrop Tuesday for the modest press event (the Conrad Murray verdict occurred an hour earlier). The Penmar Park project will capture runoff from the watershed from south-east Sunset Park in Santa Monica and the Santa Monica Airport and the Rose Avenue neighborhood near Walgrove Avenue. The cistern will store approximately 1 million gallons of runoff, which will then be disinfected and used for irrigation at the Penmar golf course and park.
The rainwater harvesting guidelines were negotiated over a two-year period with the City of Los Angeles, Santa Monica, and the environmental community, led by Heal the Bay and Treepeople. They provide clarity and certainty to project developers on how to move forward with projects that capture and reuse rainwater. L.A. County Public Health, especially Angelo Bellomo and Kenneth Murray, earn major props for moving the guidelines forward.
The structure of the guidelines is relatively simple. There are four tiers of projects:
Tier 1 is for on-site collection of rainwater with rain barrels, and the requirements are pretty limited. Most important, separate permitting isn’t required for them, so rain barrel use should proliferate now.
Tier 2 is for the on-site collection of rainwater in cisterns for on-site uses. Again, the requirements are relatively limited, especially for small cisterns on residential properties. For tier 2 and all tiers, monitoring and treatment requirements are trivial for subsurface or drip irrigation. If the runoff is used for spray irrigation or an outdoor water feature, then the runoff from the cistern needs to be disinfected to meet fecal indicator bacteria standards that are equivalent to the single sample maximum for swimming on ocean waters. Larger systems need County Public Health review in order to ensure there are no sewer cross-connections.
Tier 3 applies to cisterns that receive runoff from on-site or off-site, and for use of the runoff on-site or off-site. However, the runoff cannot come from a drainage that includes industrial land uses. Tier 3 is similar to Tier 2, but spray irrigation cannot occur during daylight hours. Runoff used for spray irrigation, water features, street sweeping, and dust control must be disinfected to meet bacteria standards. These projects would get a more thorough review from the public health department.
Tier 4 is identical to Tier 3, except that the runoff drainage area can include industrial land uses. The big difference is that the runoff from Tier 4 projects must be analyzed for toxic metals, volatile organic compounds (solvents) and semi-volatile organic compounds (petroleum) to ensure that the runoff poses no health risk to anyone that comes in contact with it.
The guidelines are common sense and should greatly help developers in their decisions to install low-impact development BMPs that capture and use runoff. Look for a proliferation of rainwater harvesting projects in the region, which should really reduce runoff pollution and reliance on imported water supplies.
The rainwater harvesting guidelines are the first of their kind in all of California. The next priority is to get all of California’s environmental health agencies to adopt similar guidelines in the near future. Also, the State Water Board should adopt the guidelines as a policy for the state. These moves would go a long way towards incentivizing rainwater harvesting projects, and moving California towards a water management strategy that includes the local, reliable source of water that comes from the sky.
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