SANTA MONICA—On Tuesday, February 16, representatives from the Los Angeles County Department of Public Health, City of Los Angeles Bureau of Sanitation, City of Santa Monica Office of Sustainability and the Environment, TreePeople, Heal the Bay, and Natural Resources Defense Council showcased a new roadmap, that gives municipalities, businesses and homeowners with ways to help with LA County’s water management and planning through the use of non-potable water both outdoors and indoors.

According to a press release from the city of Santa Monica website, the new voluntary guidelines for non-potable water use are a first for LA County and possibly throughout the state of California. Close to 80 percent of Southern California is still importing water, the roadmap Guidelines for Alternate Water Sources – Indoor and Outdoor Non-Potable Uses (aka Matrix 2.0): which is a key piece of the puzzle to assist with sustainable water supply.

Non-potable water is not expected to be consumed for drinking, but sources for on-site non-potable water include, but are not limited to, graywater, rainwater, stormwater, blackwater, cooling tower blow-down water, condensate, and foundation drainage.

“We are very excited about this next phase. One of our roles as the Dept. of Public Health is to ensure the safe use of alternate water sources (AWS) by ensuring that such systems are designed and operated in a manner to deliver appropriate water quality,” states Terri Williams, Acting Director of Environmental Health for the Los Angeles County Department of Public Health. “With Matrix 2.0, we want to change the conversation from ‘Will you allow the use of AWS on this project?’ to ‘How can we safely use AWS on this project?’”

The Matrix 2.0:

  • Provides governments with a real, tangible standard to follow for collection and treatment, giving the public a way to design a non-potable water system that can actually be approved for use.
  • Safeguards the public health while promoting decentralized, on-site alternative water use.
  • Establishes monitoring and testing parameters to ensure a system functions over time.
  • Compliments standards found in the NPDES Clean Water Act permit and EWMPS (enhanced watershed management plans) water quality standards through the use of non-potable water.
  • Develops a simple, effective process of approving plans and inspecting systems to encourage the public to build the systems, and allow jurisdictions to approve them.

By using Matrix 2.0 guidelines, the end user can:

  • Save money and energy resources by expanding use of alternate water to indoor uses, in addition to outdoor use.
  • Harvest rainwater on-site to eliminate runoff, which carries pollution to the ocean.

“We are in a long-term water crisis, as well as a short-term drought emergency, so it’s vital that our cities and property owners share stewardship in developing alternative, non-potable, on-site water supplies and uses that can reduce the need for expensive new potable water,” said Andy Lipkis, States TreePeople founder.

The presentation was held at the Pico Branch Library in Santa Monica, which has an underground cistern project that delivers water for indoor toilet flushing.

“The Matrix 2.0 represents a watershed moment in the evolution of southern California green building, and the library’s cistern is a perfect example. No longer will building projects be hindered by regulatory gaps or enforcement inconsistency with regards to alternate water reuse strategies. Our challenge is clear: we live in a growing region where the resource of water is only becoming scarcer. This groundbreaking, inter-agency effort will unlock innovation and create design opportunities so our buildings can be dramatically more resilient and water efficient,” said Joel Cesare, Sustainable Building Advisor for the city of Santa Monica.

A morning tour of the additional sites showed success with on-site water sources: a new Expo Line station with a cistern will collect water for irrigation and equipment parts cleaning; the Loews Hotel’s graywater laundry water recycling system; and the Penmar Water Quality Improvement Project, the largest stormwater cistern in L.A. County.

Williams noted that some notable projects looking to propose the use of AWS for indoor use include the retrofitting of a Beverly Hills hotel, a multi-tower development in downtown Los Angeles consisting of condos, hotel, and retail space, and the new Santa Monica City Services Building.

The new Matrix 2.0 is an enhancement of the original Matrix from 2011. The previous Matrix focused on outdoor uses of rainwater, stormwater and dry weather runoff harvest and use. New laws expanding the definition of AWS have surfaced to include new sources, allowing the advancement of AWS including within buildings for flushing restroom fixtures. New standards for water quality related to AWS, helped the need for updating the matrix.