Jason Dadakis on OCWD’s PFAS removal pilot

The Orange County Water District (OCWD) is undertaking North America’s largest PFAS pilot testing program. Ahead of the next Aquatech BreakOuts, we caught up with Jason Dadakis to find out more.

A significant problem for US utilities

The Orange County Water District (OCWD) recently scooped an award for what is being called the nation’s largest per- and polyfluoroalkyl substances (PFAS) testing programme.

Winning the Clair A. Hill Water Agency Award for Excellence from the Association of California Water Agencies (ACWA), the utility has completed phase one of the project.

Various treatment techniques are being tested by the utility to remove PFAS detected in local groundwater supplies. Multiple technologies have been tested in the district, including granular activated carbon (GAC) and ion exchange products, as well as novel adsorbents.

The district is currently working on adding 10 PFAS treatment plants throughout the area and has provided more than a year's worth of data to help determine the most effective treatment media to remove PFAS.

Jason Dadakis, executive director of water quality and technical resources at OCWD will provide an update on the programme at the next Aquatech BreakOuts, taking place on June 29 at 16:00 CET. The title of the online session is 'Futureproofing water treatment against contaminants and micropollutants of emerging concern'.

Ahead of the BreakOuts, Aquatech Online spoke to Jason Dadakis to find out more about the pilot.

Aquatech Online (AO): How big a challenge do you see PFAS becoming for water utilities?

Jason Dadakis (JD): PFAS contamination is a very significant problem for many US water utilities. With the USEPA beginning its regulatory development process towards a national primary drinking water standard for PFOA and PFOS, estimates of capital expenditures for PFAS-related drinking water treatment in the US range into the many billions of dollars, putting aside long-term operation & maintenance (O&M) costs.

AO: Your PFAS pilot project was recently recognised as an “exemplary program” by the Association of California Water Agencies. Talk to me about the processes examined here and why?

JD: Our pilot study has focused on adsorbent technologies, namely granular activated carbon, ion exchange resins, and novel alternative sorbents. These techniques are well-established in water treatment engineering, having fairly well-understood costs to design and implement at full scale. During Phase I of our study, we've conducted a side-by-side assessment of PFAS removal performance of 14 different adsorbent media from a range of vendors.

AO: Are there any notable results you can share from Phase 1 so far?

JD: All of the adsorbent technologies are initially able to remove PFAS effectively, but we have observed a wide range of contaminant breakthrough and media exhaustion behaviour. Some alternative novel sorbents marketed for improved PFAS removal have performed well and potentially offer lower operating costs.

Another notable result was that our contemporaneous lab-scale testing to predict GAC and alternative adsorbent performance matched our pilot quite well once we ran the pilot long enough to observe significant breakthrough; this helps validates the use of the standardised lab method ('rapid small-scale column testing') for PFAS to predict full-scale media life.

However, one area where we have continued uncertainty is on the costs to dispose or regenerate spent treatment media or other residuals, which will be driven in part by future state and federal regulatory decisions.

AO: How do you see the area of PFAS removal leading to further market innovation and partnerships?

JD: It does appear as though a number of smaller start-up companies are working to develop novel treatment technologies. These newer vendors sometimes have only been able to demonstrate treatment performance in a very controlled laboratory setting and lack rigorous field-testing experience.

There are likely opportunities for these smaller players to work with universities and/or consulting engineers in demonstrations of “real-world” performance such that water utilities and regulators become comfortable with the use of their technologies at full-scale permitted facilities.

AO: California is also looking to take the lead when it comes to setting state-wide levels for microplastics in water. Tell me more about the drivers behind this?

JD: The primary driver is a law (SB 1422) passed by the State of California legislature in 2018, which directed its drinking water regulators to a) adopt a definition of microplastics in drinking water by July 1, 2020 and b) adopt a standard methodology to analyse drinking water for microplastics, along with a requirement for four years of testing and reporting, by July 1, 2021.

No other governmental body in the world has certified a standard analytical technique or developed a health-based threshold for microplastics in drinking water, so state regulators have been challenged by the law’s aggressive schedule and the relative infancy of the state of the science. It is likely that the state will issue advisory guidelines to help water agencies and consumers assess the results of the required testing.

AO: What are you hoping will be a key takeaway from your talk in the BreakOuts for international utilities?

JD: That in its role as the local groundwater basin manager, Orange County Water District has taken a proactive and collaborative approach in addressing PFAS with its retail agency stakeholders to restore the local water supply quickly and efficiently.

- The Aquatech BreakOuts on water quality will take place on June 29 16:00 CET.