One Sacramento well tested over the PFAS limit EPA proposes to repeal, and over the two limits it would keep

City of Sacramento Well 133 was sampled for PFAS on October 5, 2023 and again on February 22, 2024. The second sample read 19.1 parts per trillion (ppt) of PFHxS, a chemical EPA capped at 10 ppt in 2024 and proposed in May to stop capping. The same sample read 41.4 ppt of PFOS and 15.6 ppt of PFOA, against federal limits of 4 ppt each that EPA intends to keep. Those figures come from EPA's fifth national round of drinking water testing, UCMR 5.

Well 133 is the only one of 288 sampling points in Sacramento and Yolo counties that EPA's own counting method puts over a limit it wants to repeal. It is also over the limits EPA wants to keep. So repeal would not take this well off the federal list. It would remove one of the three federal numbers attached to it, and that number is the same 10 ppt that California already uses.

What the testing covers, and what it does not

I downloaded EPA's by-state UCMR 5 file, dated October 15, 2026, and kept every system whose identifier carries the Sacramento County code (34) or the Yolo County code (57). That is 35 systems: 30 in Sacramento County and 5 in Yolo (Davis, West Sacramento, Winters, Woodland and UC Davis). Together they reported 288 sampling points, sampled between 2023 and 2026. Each point is an entry point, where water leaves a well or plant for the pipes. It is not a tap. Wells were sampled twice, six months apart; surface-water intakes four times.

EPA's July 2026 data summary says plainly that UCMR 5 results "do not indicate compliance or noncompliance" with the limits. Compliance will be a running annual average at each point. So I averaged each point's readings, counting a result below the lab's reporting limit as zero, which can make an average run low. I also used EPA's rounding. Because the PFHxS limit is written as 10 and not 10.0, EPA counts an average as over it only at 15 ppt or more. Well 133 averaged 18.8 ppt. Two other points read just above 10 ppt once: City Well 124 at 10.4, which has one reading and so no full set, and the Countryside Way well in California American Water's Suburban Rosemont system, at 9.0 and 10.9. Neither counts under EPA's rule.

Eight systems cross the limits that stay

Of the 34 systems with at least one complete set of readings (West Sacramento's single river intake had three), eight had a point averaging 4.05 ppt or more of PFOA or PFOS, the threshold EPA uses. They are the City of Sacramento, Sacramento County Water Agency's Laguna/Vineyard and Arden Park Vista systems, California American Water's Rosemont, Parkway and Arden systems, Florin County Water District and the California State Fair. Well 133 sits in the first of those, one of 11 points in the city's system with a full set. Davis, Woodland, West Sacramento and UC Davis had no reading above the lab's reporting limit for any of the six PFAS in the federal rule; Winters had one PFNA reading of 4.2 ppt at Well 6.

Nationally the rescinded limits touch far fewer systems than the kept ones. EPA's summary counts 875 systems with an average over the PFOS limit and 779 over PFOA, against 66 for PFHxS, 9 for PFNA, 8 for GenX and 80 for the mixture limit, out of about 10,100 systems. A system can appear in more than one row. EPA's proposal uses that gap: the notice puts the saving from dropping the PFHxS limit at $11.6 million a year in quantified costs, against about $6.7 million in expected benefits lost (2022 dollars).

California's levels do not move when EPA's do

The state Division of Drinking Water lists a response level of 10 ppt for PFHxS and PFOA and 40 ppt for PFOS, issued October 29, 2025; its page was updated August 17, 2026. The state says systems that detect a chemical above its response level "shall take a water source out of use, treat the water delivered, or provide public notification." Well 133 is over the state's PFHxS level (18.5 and 19.1) and its PFOA level (17.3 and 15.6), and its February 2024 PFOS reading of 41.4 is over 40. Those levels were set after these samples were drawn. Two more points had a single PFOA reading over 10: Sacramento County Water Agency's Well 42 at 14.0 and Florin County Water District's Kara Well at 11.8. All four of the PFHxS readings above 10 in this data, at Wells 124 and 133 and Countryside Way, sit over the state level whatever EPA decides.

The city's water quality page says that if a source "exceeds regulatory levels for PFAS, it is taken out of the City's water distribution system," and that the city's water "continues to meet all Federal and State drinking water standards." The page names no wells and does not say which levels count as regulatory. A federal limit that is enforceable only from 2029, a state response level that is a trigger for action rather than a ceiling, and a repealed limit are three different answers. UCMR 5 cannot say whether Well 133 was serving customers on the sample dates, whether it serves them now, or which of those levels the city counts as regulatory. I have not yet put those three questions to the Department of Utilities.

A procedural argument, and a court that has not ruled

EPA's stated reason for the repeal is procedure, not the toxicity of PFHxS. The proposal says EPA proposed and finalized its determinations to regulate these chemicals at the same time as the limits, and that under "the best reading" of the Safe Drinking Water Act it may not. A companion proposal lets systems that ask move the PFOA and PFOS deadline from 2029 to 2031. Both were published May 20, 2026, and the comment period closed July 20. I found no final rule in the Federal Register as of October 21.

The 2024 rule is also being tested in the D.C. Circuit. American Water Works Association v. EPA, No. 24-1188, filed June 7, 2024 by the utility groups, now runs with two industry petitions, Nos. 24-1191 and 24-1192. On March 19, 2026 the court denied a motion to sever the case and hold it in abeyance, so the case stayed on its schedule while EPA's proposal was pending. The clerk set oral argument for September 18, 2026, and CourtListener holds a recording of that argument, 1 hour 21 minutes long. CourtListener's copy of the docket, which it says may not be current, has no entry after September 15 and shows no decision, and I could not reach the court's own opinions page from here, so a ruling after that date is not ruled out. If EPA finalizes the repeal before the court rules, part of the case could turn on a rule that no longer exists. That is my reading, not the court's.

The window for comment has closed

No federal comment date is open on either proposal. The next one comes only if EPA publishes a final rule, and I found no date for that. What a Sacramento reader can do now is read the city's latest Consumer Confidence Report, which the city says lists measured PFAS, and put the three questions above to the Department of Utilities. One finding from this data stands on its own. At every point where PFHxS read above 10 ppt, PFOS or PFOA read above 4 ppt in the same sample. In Sacramento and Yolo counties from 2023 to 2026, the PFHxS limit would have caught no water that the limits EPA is keeping do not. A well with PFHxS and none of the others would change that, and this testing found none.