Balancing Conservation and Quality: Addressing Water Age in California’s New Regulations
The California State Water Resource Control Board (SWRCB) announced a mandatory cut of 39% in water use by 2040. This decision is crucial for promoting efficient water use across California and addressing the state's water supply shortfall.
While the financial implications of this mandatory conservation have been noted—initially estimated at $13.5 billion and revised to $4.7 billion due to extended compliance timelines—the impact on water quality remains underappreciated and unaccounted for in compliance costs.
On one hand, all will agree that water conservation is critical to meet the growing demand for water and achieve sustainability. However, since the drinking water distribution system infrastructure is already in place, it is important to understand and consider the impact of reducing water usage (i.e., demand) on the quality of water remaining in the distribution system.
For that purpose, I prepared a white paper describing in detail the impact of water conservation programs on water quality management in drinking water systems. Download the white paper here:
It discusses the adverse effects of reduced water usage on water quality, the challenges faced by distribution system operators, and the importance of incorporating technological solutions to mitigate these issues.
A critical issue is that reduced water usage increases water age within distribution systems, adversely affecting water quality. For instance, trihalomethanes (THMs), regulated under the Stage-2 DBP rule by the EPA, can rise with increased water age, potentially surpassing the maximum contaminant level (MCL) of 80 ppb. This poses new compliance challenges for water utilities already dealing with elevated THM levels.
Fortunately, existing and proven technologies, like the PAX TRS™ in-tank aeration system in drinking water storage tanks, can mitigate and remove THMs post-formation, effectively resetting water age and ensuring safe water quality. By targeting portions of the distribution system where water age is expected to be high, this solution allows for managing THM levels where they are a concern. Other alternatives typically require costly upgrades to treatment plants to reduce THM precursors.
Investments and careful planning will be necessary to address these water quality impacts, balancing usage reduction with the need for safe water and storage for emergencies. Incorporating these considerations into the cost of compliance is essential for holistic water management in the future.
For further reading on the new regulations:
Discuss the impacts of water conservation on your system.
