Comprehensive PFAS Treatment Cost Estimates for Various Types of Water

When estimating cost for per- and polyfluoroalkyl substances (PFAS) treatment, the industry often underestimates the true cost of PFAS treatment by focusing on just primary treatment costs. In order to capture the true cost of PFAS treatment, Geosyntec developed a holistic engineering approach to cost estimation that include the capital expenditure (CAPEX) and operating expense (OPEX) for the i) PFAS treatment unit itself, ii) pretreatment unit to meet the desirable and/or feasible water quality for the PFAS treatment unit, and iii) managing the residuals generating during the pretreatment and PFAS treatment units.

As a first step, Geosyntec reviews all available flow and water characterization data to identify existing gaps and recommend additional data collection. The water characterization data needed for holistic PFAS treatment evaluation is generally classified into breakthrough/performance parameters, pretreatment technology parameters, competing parameters, corrosion parameters, and charge/ionic balance parameters. Geosyntec then utilize this water characterization data to identify the need for pretreatment and auxiliary components and screen potential PFAS treatment technologies.

This framework has been successfully applied across multiple water matrices (e.g., groundwater, stormwater, wastewater, and landfill leachate) to formulate diverse and innovative solutions for various entities and industries. This success is achieved through Geosyntec's close collaboration with technology vendors, whether utilizing more established technologies (e.g., granular activated carbon [GAC], ion exchange [IX], and reverse osmosis [RO]) or emerging technologies (e.g., novel adsorbents, foam fractionation [FF], electrochemical oxidation [EOx], supercritical water oxidation [SCWO], and smoldering) to prepare a comprehensive rough order of magnitude (ROM) cost estimate.

Table 1 summarizes five comprehensive PFAS treatment cost estimates for different types of water and various design flows. The holistic cost is broken down into non-treatment units (e.g., tanks and pumps), pretreatment unit, PFAS treatment unit, and residual management. It is noted that the CAPEX cost for each breakdown category is calculated as the ratio of the sub-category CAPEX to the total CAPEX, which is proportional to the ratio of the sub-category equipment cost to the total equipment cost. Therefore, the sub-category CAPEX includes non-components (mechanical, electrical, civil, structural), installation, freight, tax, contractor cost, contingency, etc.

The comprehensive cost estimate helps clients avoid unexpected costs and make informed decisions about PFAS treatment implementation. This is especially valuable for more complex matrices, such as wastewater and leachate. As indicated in Table 1, Project III and Project V have CAPEX and OPEX for the pretreatment units that are either higher or comparable to those of the PFAS treatment unit. In contrast, Project I, Project II, and Project IV, which treat PFAS in less complex matrices (e.g., groundwater and stormwater), have lower CAPEX and OPEX for the pretreatment units compared to the PFAS treatment unit.