The Local Water System and How PFAS Reach Your Tap
Des Moines Water Works serves roughly 246,000 people across Polk County using surface water sources. Water is drawn from these sources, treated at centralized facilities, and delivered through a vast network of pipes to homes and businesses. The water system is regularly sampled for emerging contaminants including PFAS—per- and polyfluoroalkyl substances—sometimes called "forever chemicals" due to their persistence in the environment.
Understanding the Hazard Index for Mixes of Newer Fluorinated Compounds
PFAS includes various compounds like PFOA, PFOS, PFHxS, PFNA, and several others. Rather than evaluating single compounds in isolation, scientists calculate a hazard index that represents the combined potential impact of these chemicals. Importantly, a hazard index does not indicate a violation or unsafe condition; it provides a relative measure to prioritize monitoring and treatment efforts. In Polk County’s Des Moines Water Works system, federal surveys detected no individual PFAS compounds above reporting levels or upcoming federal maximum contaminant levels (MCLs) set for 2024, indicating a low hazard index for the treated surface water.
Firefighting Foam, Textile Finishing, and Landfill Sources: What Fits Polk County’s Record?
Common local PFAS sources include historical use of firefighting foams, manufacturing facilities, and waste disposal sites. In Polk County, data from 2023-2025 EPA monitoring shows no measurable PFAS from these sources in the public water system’s treated supply. This absence suggests that, in this region, surface water treatment and source protection have limited PFAS presence tied to such activities.
Interpreting 'Detected,' 'Median,' and 'Range' in the Monitoring Data
The monitoring results list 12 samples for each PFAS compound from February to November 2023. 'Detected' means the chemical was found above the instrument's minimum reporting level, not a health or safety violation. Here, none of the samples showed PFAS above reporting levels. 'Median' and 'range' describe the statistical distribution of results, but with no detections, these values are not applicable. This data confirms no measurable PFAS in the system's recorded supply during this period.
Granular Carbon Bed vs. Ion-Exchange Resin: Different Approaches to PFAS Treatment
When households evaluate treatment options for PFAS, two common technologies are granular activated carbon filters and ion-exchange resins. Granular carbon beds adsorb PFAS molecules onto their surface, effectively reducing concentrations of longer-chain compounds. Ion-exchange resins, by contrast, actively bind PFAS through chemical exchange processes, often targeting shorter-chain compounds more efficiently. Both approaches address different PFAS profiles and may be combined for broad-spectrum treatment. The Fleck PFAS Forever Chemicals Filter employs these documented technologies and ships ready to configure for home use.
Seasonal and Multi-Year Variations in PFAS Measurements
Water quality can change seasonally or over years due to fluctuations in source water, treatment practices, and environmental factors. Polk County’s monitoring, covering early 2023 through late 2023, showed consistent nondetect results across all tested PFAS compounds. Continued sampling is needed to observe any emerging trends but current data suggest stable low levels in the public supply.
Additional Questions for Commercial or Industrial Operators
While households focus on basic PFAS presence and treatment, commercial and industrial facilities often assess specific compound concentrations, effluent discharge limits, and regulatory compliance for multiple water sources, including groundwater and process water. Detailed testing beyond the municipal supply may be required for such operations. Households can usually start with system water testing to determine the need for home treatment.
Next Steps: Testing Your Household Water for PFAS
The single most informative action for a Polk County household considering PFAS treatment is to obtain a laboratory analysis of their own tap water for the suite of regulated PFAS compounds. This test will reveal if PFAS are present above the minimal reporting levels and guide the choice of an appropriate home water treatment method. Should measurements show PFAS within detectable ranges, technologies like the Fleck PFAS Forever Chemicals Filter provide a documented solution to reduce these fluorinated compounds effectively.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2023-11-14. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR5 monitoring (2023-2025) for DES MOINES WATER WORKS (IA7727031), IA: 120 results across 10 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level