RFP 88th & Pine Design and Services of a Granulated Activated Carbon System
Request for Proposals
Design and Services of a Granulated Activated Carbon
PFAS Treatment System for Wells J-1, J-2, and J-3 at 88th and Pine St.
2700 88th St SW Lakewood, WA 98498
Proposals are Due on Wednesday, August 2, 2023
The Lakewood Water District (District) is seeking proposals from consultants to provide design and permitting assistance services for the addition of a granulated activated carbon (GAC) filtration system for the removal of PFAS at the District's existing Wells J-1, J-2, and J-3 at the District's 88th St and Pine well site. The new PFAS treatment system will be designed to filter approximately 2,000 gpm of water produced from the District's three wells at the site. The existing wells draw from two different aquifers. J-1 and J-3 draw from aquifer A, and J-2 draws from aquifer E. The treatment system for the three wells (Wells J-1, J-2, and J-3) should be designed with the possibility of increasing the flow rate in the future. Wells J-1 and J-3, in shallow aquifer A, have low levels of PFAS, and J-2 in aquifer E has elevated hydrogen sulfide, which will be removed through the GAC treatment process.
Project Background
In June of 2022, the United States Environmental Protection Agency (EPA) published a proposed Maximum Contaminant Level (MCL) levels for six PFAS compounds, perfluorooctane sulfonate (PFOS) - 4 ppt and perfluorooctanoic acid (PFOA) - 4 ppt. EPA’s proposed rule includes the use of a hazard index to consider the combination of four contaminants: Perfluorononanoic acid (PFNA), Perfluorohexanesulfonic acid (PFHxS), Perfluorobutanesulfonic acid (PFBS) and GenX. This project will treat the wells to filter PFAS from the drinking water to levels that meet the proposed EPA MCLs.
Per-and polyfluoroalkyl substances (PFAS) are a group of man-made toxic chemicals that include PFOA, PFOS, PFNA, PFHxS, PFBS, GenX, and many other chemicals. These chemicals are not found naturally in the environment. PFOA and PFOS have been the most extensively produced and studied of these chemicals. There is evidence that exposure to PFAS over time may lead to adverse human health effects.
In 2016, Joint Base Lewis McChord (JBLM) sent out a press release notifying the District that high levels of PFAS were found in 5 of the military base’s wells as concentration levels were in excess of the EPA’s health advisory level of 70 ppt during the UCMR3 monitoring. After sampling of water produced from District wells close to JBLM, it was found that PFAS was detected well below the EPA health advisory level of 70 ppt. As a result, the District implemented ongoing monitoring of its shallow aquifers – the A-level and C-level aquifers. PFAS levels detected at the 88th and Pine site have remained below both the EPA health advisory level and the State Dept. of Health State Action Level (SAL). However, in anticipation of the EPA’s proposed MCL levels, the wells would be above the proposed MCL.
