Drinking water facilities have less time to respond to a growing number of threats to their missions of reliably delivering clean water to their users. This is especially true in California, which, for several reasons, is under the gun to increase the speed with which they upgrade their systems.
Groundwater sources account for about 40% of all water consumption in the state during an average year. During droughts, some systems that depend on surface water turn to groundwater, which can drive up the proportion of water coming from groundwater to approximately 60%. Nearly 85% of Californians depend on groundwater for some portion of their water needs. This makes groundwater management an important mission to the majority of public water systems in California.
Industrial chemicals such as tetrachloroethylene (PCE), trichloroethylene (TCE), hexavalent chromium and per- and polyfluoroalkyl substances (PFAS) are a concern, particularly in parts of urban areas in southern California. Nutrients such as nitrate from fertilizer and manure are present in groundwater in many farming areas. Some naturally occurring contaminants, such as arsenic, also pose challenges.
California’s efforts to protect its vulnerable water supply revolve around government regulations—both federal and state. These rules target PFAS, chromium 6, 1,2,3-TCP, 1,4-dioxane and other legacy contaminants that have historically plagued groundwater resources. Many wellhead/groundwater treatment systems need upgrades and expansions to comply with these regulations.
Through a safe drinking water regulation finalized in April 2024, the Environmental Protection Agency (EPA) set new national maximum contaminant levels (MCLs) for six PFAS compounds: 4 parts per trillion (ppt) for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), 10 ppt for perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA) and hexafluoropropylene oxide dimer acid (HFPO-DA) and a hazard index of 1 for PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA and perfluorobutane sulfonate (PFBS) to account for the combined and co-occurring levels of these PFAS in drinking water. By April 2029, public water systems must show PFAS levels of no more than these MCLs.
In 2024, the California State Water Resources Control Board lowered the MCL for chromium 6 in drinking water. Chromium 6 is a chemical compound found in groundwater (from both natural sources and industrial activity) that can cause cancer and liver disease. At 10 parts per billion (ppb), the new MCL must be achieved on a rolling schedule depending on utility size, starting Oct. 1, 2026, for systems with 10,000 or more connections. For systems with 1,000 to 9,999 connections, the MCL must be achieved by Oct. 1, 2027, and for systems with fewer than 1,000 connections, the compliance deadline is Oct. 1, 2028.
These MCLs join another state MCL that addresses groundwater contamination. In 2017, the California State Water Resources Control Board established an MCL of 5 ppt for 1,2,3-TCP. This regulation mandates that public water systems must regularly monitor for this contaminant and, if levels exceed the MCL, notify the public and take corrective action, such as installing treatment technologies or shutting down the well.
Regarding 1,4-dioxane, there is no enforceable MCL yet, but California has set a notification level of 1 ppb, which requires public water systems to inform local governing bodies if the system detects levels above this threshold.
Given the regulatory compliance deadlines and California’s water system vulnerability to effectively manage water, time is a precious asset. Many systems in California, for example, now have less than two years to reduce chromium 6 MCL to 10 ppb, and if they fail to meet this deadline, they could face a well shutdown. Weatherproofing upgrades to facilities and infrastructure likewise are less of a “like to have” and more of a “must have” investment than they used to be.
The conventional design-bid-build (DBB) approach to capital improvements at water treatment plants may be unfeasible for the time frame now faced by California water systems. While still a strong option when time is not an issue, DBB may not provide adequate time for preparedness and current PFAS and chromium 6 compliance deadlines. Planning and design typically take a year, followed by another six months for bid solicitation and evaluation. Construction, commissioning and testing add another year to 18 months. Add a few months due to delays of various kinds, and it could easily be three and a half years or more before the project is operational.
Design-build (DB) is a modified version of DBB that has been around since the early 2000s and can accelerate the project timeline by combining architectural, engineering and construction services into a single contract. However, it does not always adequately mitigate risks to owners or contractors.
Collaborative delivery is an alternative method to DBB and DB that maximizes collaboration, minimizes risk and streamlines processes to increase efficiency and meet compliance deadlines and other rushed scenarios.
There are several kinds of integrated solutions for water utilities today.
Effective Jan. 1, 2023, the passage of California Senate Bill 991 allows local agencies to use progressive design-build (PDB) delivery for water and wastewater projects. With PDB, the owner hires a contractor-led team that includes the general contractor and design engineer, who collaborate throughout the project with the owner to expedite both design and construction. The owner negotiates a guaranteed maximum price (GMP) with the construction firm to establish a risk-sharing agreement. With collaboratively developed pricing and greater utility input, the owner receives more insight into cost drivers, helping to avoid expensive change orders and claims and also ensure that operational needs and regulatory requirements are met.
Another model is construction management at risk (CMAR), which has been available to counties in California since 2013. Like PDB, the architect/engineer works collaboratively with the construction firm and site owner, and this model delivers similar benefits. The main differences are that the owner will hold the contract with the engineer. The owner will have a little more control over design, but that control will come at the price of a slightly slower pace (but still generally faster than DBB).
Public private partnerships (P3) are partnerships between government entities and private investors that can effectively finance public water infrastructure projects. On the upside, this arrangement is a good option if the utility lacks funding or wants to preserve its cash position, and it can save time during the funding phase (but not always). On the downside, in exchange for taking on that risk, the investor assumes more control over design, so it is critical for the owner and investor to be aligned as to mission, timeframe and other values from day one.
These collaborative vehicles can compress project schedules down to 50-60% of the time needed by a DBB approach. What would otherwise take three and a half to five years can take just 24 to 30 months. Under current compliance deadlines and the pressures of delivering clean, reliable water sources in California, this timeline is a much better fit—and can deliver cost savings too.
