With the Mendocino Unified School District (MUSD) assuming authority for Mendocino City Community Services District’s (MCCSD) $5 million, publicly funded water supply and storage project, a project initiated by MCCSD in 2021 to meet Mendocino’s emergency water needs during drought, alternatives are desperately needed to reduce the community’s reliance on this, yet another imported supply, and to develop potable supply and storage with longer carryover potential - this time, which remains firmly in the hands of the one-square mile the community services district is authorized to serve.
Most water experts agree that the only way to become sustainable is to lower demand until it matches supply. Some fear that this will hurt the economy, when the reality is that resources are finite and in control. It’s clear the unconfined, highly-rainfall dependent aquifer that lies under Mendocino is not only stressed, but that the place has developed beyond its capacities: the town simply lacks the groundwater resources it requires to sustain current needs. Continued reliance on neighboring water systems and watersheds is not living within ones means. Driven by necessity and experience, the challenge then becomes how best to provide safe, clean, and affordable water while maintaining the integrity of healthy ecosystems and critical habitat: in essence, balancing the needs of society with those of the environment.
Living in Mendocino has historically instilled a strong water conservation ethic in those who have lived there. For the last 52 years, residential groundwater allotments have been controlled, water use managed, and indulgences like fountains, pools, and irrigated lawns - if not considered downright taboo, then inexcusable. But even with these measures, new concepts in water and wastewater infrastructure require consideration. They have to. We’ve little choice in coastal northern California, where ongoing climatic shifts will continue to affect the reliability of local water supplies. It is projected that over the next twenty years, California could lose 10% of its water supplies as the climate changes, resulting in longer droughts, heavier precipitation events, less average snowfall, and increased evapotranspiration consumption of water by vegetation, soil, and the atmosphere. One of the largest global institutions, the World Bank, reports that some regions could expect their growth rates to decline by as much as 6% by 2050 as a result of water-related losses in agriculture, income, and prosperity.
Opportunity lies in the direct potable reuse of recycled wastewater, or “DPR.” Groundwater extraction and desalination, once thought of as silver bullets, saviors that could insure unlimited water security, are not without serious constraints. The cumulative impacts of escalating levels of groundwater pumping is now showing to have had global consequences. In a recent study of the journal of Geophysical Research Letters, climate model estimates indicate that groundwater depletion has been significant enough to cause the Earth’s axis of rotation to drift approximately 2.6 feet between 1993 and 2010. And given desalination’s costs to ratepayers, its high energy use, GHG emissions, and impacts to marine and estuarine life, it is considered by many authorities to be an option of last resort, an investment to be made only after water conservation and efficiency targets are met. DPR, on the other hand, provides multiple benefits to increase climate resiliency and local water security; it is projected to dominate over desalination for several critical reasons.
First, the technology to produce high-quality, purified water from reclaimed wastewater is here. It is mature technology, it’s effective, and it’s on the fast track to become a core component of California’s future water systems. Just last year, research engineers from Stanford University showed that recycled wastewater is not only as safe to drink as potable water, but that it may even be less toxic than many sources of water since more extensive treatment is conducted. Years earlier, the U.S. National Academy of Sciences concluded that the health risks from drinking water produced by the advanced treatment of wastewater did not appear to be any higher and may possibly be lower than any risk of conventionally treated water. Currently, 2.6 million acre-feet annually of wastewater goes unrecycled in the state with 1.7 million acre-feet of it is discharged to the ocean. AB 574 (2017) will establish uniform water recycling criteria protective of public health and create new regulations which are expected late this year. The state is reportedly on target and has gone even further with the regulations; in fact, a first draft of the regulations was released just last week by the State Water Resources Control Board. The Ocean Protection Council has also set goals for recycling wastewater and the state’s Ocean Strategic Plan has ambitious intentions to recycle 100% of it.
Not only is DPR a drought-proof water source, it is two to three times less costly than desalination, it can reduce aquifer contamination caused by over-pumping, and can decrease or eliminate the discharge of wastewater into rivers and seas. The more wastewater that can be recycled and reused, the less that must be extracted from natural and politically-contentious river and groundwater systems such as Hare Creek, Jack Peters Creek, Slaughterhouse Gulch, the Noyo, Big, and Navarro rivers, their headwaters, tributaries, seeps, springs, or alluvium – all of which are protected under public trust law - and the more people, services, and food that can be supported. With environmental stressors mounting, we can’t continue to take from our natural water resources and wonder where the fish went. Livelihoods, as well as species, depend upon our success.
Few towns are better poised to engage DPR than Mendocino. If the development of a public water system, which was announced by MCCSD at a SAFER meeting last November is indeed “the goal”, the time to develop DPR infrastructure is now, while state and federal funding remains available. Just two weeks ago, NOAA announced 575 million dollars available in grant funding to benefit resiliency projects specific to coastal communities. In Mendocino’s case, a hybrid solution may even be possible, whereby the thirsty transient population (tourism and hospitality) and landscape irrigation, which consume the lion’s share of water in Mendocino, is provided with DPR supplies and the resident population elects to maintain private, tested wells for domestic purposes, thereby lessening impacts on local surface and groundwater resources while insuring every Californian’s right to the safe, clean, affordable and accessible water guaranteed to them under AB 685 (2012), the Human Right to Water. It could also revise and relieve the financial burdens on the town’s wastewater treatment plant, where expensive infrastructure improvements are needed such as the replacement of an ocean outfall and construction of a secondary new treatment unit. Best of all, DPR has the potential to cut the plant’s ocean discharge well in advance of the state target dates - when it will become necessary to do so.
If coastal communities are serious about expanding their capacity to treat wastewater in anticipation of a drier future ahead, there’s plenty of work to be done outside of pursuing grant funding. Water supply targets based upon reasonable, equitable water consumption levels and appropriately sustainable levels of carefully-managed growth needs to be established. Cost-benefit analyses need to be developed and political and regulatory factors investigated. Honest, transparent public dialogue is needed to outline needs and consider impacts on ratepayers to avoid economic shock, especially in disadvantaged communities. Gaps in hydrologic data need to be daylighted and an open-sourced water data platform developed which is verified, trusted, and fully accessible to the public in the spirit of AB 1755 (2016), the Open and Transparent Water Data Act, with the hopes of minimizing conjecture and maximizing evidence-based, data-driven decision-making.
Crippling, multiple-year drought forces the awareness that water is not only precious, it is finite and exhaustible. It’s not free and with the development of a public water system, it will become very expensive. Societal habits of using water once and discarding it are the past. Climatic variabilities will result in multiple impacts that will require new thinking, new habits, and a fundamental shift in how water is understood, valued, and managed. Wastewater must be seen as no longer a liability, but a way forward to a more sustainable and equitable future, and an asset whose true value is security.