☎ (888) 264-7050
Two Kansas Counties Flagged Under the 9.0 Microgram PM2.5 Standard, With Final Designations Due February 2027
← Back to Blog Environmental

Two Kansas Counties Flagged Under the 9.0 Microgram PM2.5 Standard, With Final Designations Due February 2027

EPA flagged monitors in Sedgwick and Wyandotte counties under the 9.0 ug/m3 PM2.5 standard. Kansas designations go final February 6, 2027. What changes.

by iSi Environmental

Two Kansas Counties Flagged Under the 9.0 Microgram PM2.5 Standard, With Final Designations Due February 2027

EPA Region 7 sent Kansas its 120-day letter on September 29, 2026. Two counties are named in it: Wyandotte and Sedgwick. Each contains a valid monitor whose design value may not meet the 9.0 ug/m3 annual fine particulate standard, and EPA has to issue final initial designations for every area in the country by February 6, 2027 (91 FR 63516). National coverage of this round counted states. For a plant in Wichita or Kansas City, Kansas, the operative number is two counties.

The companion fact went unreported. Three of the region’s five major metros came out of this round clean. Tulsa and Oklahoma City carry no flagged monitor, and Nebraska is intended attainment or unclassifiable statewide, so Omaha is clear. Only Wichita and the Kansas side of Kansas City have monitors EPA says may not meet the standard (EPA Region 7 letter to Kansas, 2026-09-29).

One precision point before anything else. No Kansas county has been formally named intended nonattainment. EPA’s letter flags counties whose monitors “may not meet” the standard and invites Kansas to submit more information. That is a different legal posture than a proposed designation, and it is why there is still something worth doing in October.

What EPA Actually Sent Kansas

Which Kansas counties did EPA flag under the 2024 PM2.5 standard?

Two: Wyandotte and Sedgwick. EPA Region 7’s September 29, 2026 letter says each contains a valid monitor whose design value may not meet the 9.0 ug/m3 standard. Cherokee County is flagged through an out-of-state monitor in the Joplin-Miami, MO-OK-KS area. Ford, Shawnee and Sherman have insufficient monitoring data (KS 120-day letter).

Kansas had recommended both Wyandotte and Sedgwick as unclassifiable. EPA disagreed on the monitors and kept the rest of the state in the attainment or unclassifiable column. The three insufficient-data counties are not a problem on their face; EPA treats them as an opening for Kansas to submit records that support a valid design value.

What is the 2024 annual PM2.5 NAAQS?

9.0 micrograms per cubic meter, measured as an annual arithmetic mean averaged over three consecutive years. EPA lowered it from 12.0 ug/m3 in February 2024. The standard is implemented through area designations, which EPA must finalize by February 6, 2027 under a court order it is appealing (91 FR 63516).

The three-year averaging gets skipped in most summaries, and it changes how a facility should read its local monitor. A design value is a rolling number. A county flagged on one data window can move either direction by the next round.

Has EPA designated Wichita as nonattainment?

No. EPA has not formally named any Kansas county intended nonattainment. The September 29 letter states that monitors in Sedgwick and Wyandotte “may not meet” the standard and invites Kansas to submit additional information by November 1, 2026. Final designations are due February 6, 2027 (KS 120-day letter).

Kansas’s own recommendation to EPA reported a 2021-2023 design value of 9.7 ug/m3 at the Wichita Health Department monitor and 9.6 ug/m3 at the JFK monitor in Wyandotte County (Kansas initial designation recommendation). Those are Kansas’s 2021-2023 numbers, not the values EPA will designate on. The 2023-2025 design values that will actually drive the February decision are not published in the 120-day letter, and we are not going to put a number in your hands that we cannot point at a primary source for.

When are the PM2.5 designation deadlines?

Three dates. States, territories and Tribes may submit additional information by November 1, 2026. Public comments on EPA’s intended approach close November 5, 2026 under docket EPA-HQ-OAR-2024-0078. Final designations are due February 6, 2027 under the July 17, 2026 order of the Northern District of California (91 FR 63516).

EPA announced the nationwide round on October 2, 2026, notifying 50 states, the District of Columbia, five territories and 67 Tribes, then published the Notice of Availability on October 6 opening a 30-day comment window (EPA news release).

November 1 is not your deadline. It is KDHE’s. The state submits to the docket, so a facility owner holding monitoring or meteorological data bearing on whether a monitor represents its county should route that data through KDHE rather than file alone. November 5 is the date a company files on directly, and it is the weaker lever.

The Regional Read

Are Tulsa, Oklahoma City or Omaha affected?

No. EPA did not flag Tulsa or Oklahoma City. Oklahoma’s flagged counties are Ottawa, through the Joplin-Miami multi-state area, and Carter, for insufficient data. Nebraska is intended attainment or unclassifiable statewide, so Omaha is clear. Of the region’s major metros, only Wichita and Kansas City, Kansas carry flagged monitors.

Oklahoma DEQ’s own preliminary 2023-2025 annual values sit under the standard: 8.9 at OKC Downtown, 8.8 at Moore, 8.6 at Tulsa Central (ODEQ annual PM2.5 monitoring data). An Oklahoma manufacturer reading national headlines about 30 states has no exposure here unless it operates in Ottawa County. Arkansas is the other side of that coin: Pulaski, Garland, Union, and Little River and Miller are flagged.

Does the Kansas City, Missouri side get pulled in?

Yes, indirectly. Missouri has no failing monitor of its own, but nine Missouri counties in the Kansas City area are flagged through an out-of-state monitor, the Wyandotte County, Kansas monitor. Jasper and Newton are flagged through Joplin-Miami, and five St. Louis counties through an Illinois monitor (EPA Region 7 letter to Missouri).

That mechanic surprises people every designation cycle. A Missouri source can land inside a nonattainment area on the strength of a reading taken in another state. In the KC metro, your permitting agency and your designation risk are set by two different things, which is why the metro’s three-agency permitting map is worth having in front of you first.

What a Designation Would Change

What does a PM2.5 nonattainment designation trigger for a manufacturer?

Nonattainment New Source Review. In a Moderate PM2.5 area the major-source threshold drops to 100 tons per year of PM2.5 or any precursor, meaning SO2, NOx, VOC or ammonia. New major sources and major modifications must meet LAER, obtain emission offsets at a ratio of 1:1 or greater, and certify compliance at the owner’s other in-state sources under CAA Section 173 (40 CFR 51.165).

The state side moves too. Kansas would owe a Moderate-area attainment plan with reasonably available control measures and RACT within 18 months of designation (40 CFR 51.1003). That SIP is where control requirements for existing sources get written, so the 18-month clock reaches facilities that never build anything. If you want to see the LAER-and-offsets sequence running in a mature nonattainment area, the Texas ozone permitting rules show the same machinery under a different pollutant.

What is the major source threshold in a PM2.5 nonattainment area?

100 tons per year of PM2.5 or any precursor, meaning PM2.5, SO2, NOx, VOC or ammonia, in a Moderate area (40 CFR 51.165). If an area is later reclassified Serious, the threshold falls to 70 tons per year, which pulls in mid-size sources that were comfortably minor under Moderate arithmetic.

Reclassification is not theoretical. What a Serious-area ratchet does to a permit file years after initial designation is laid out in the San Joaquin Valley record. Kansas is nowhere near that posture, but it is the trajectory a 15-year capital plan should account for.

How do I know if my facility would be a major source under nonattainment NSR?

Pull current potential to emit for PM2.5 and all four precursors, SO2, NOx, VOC and ammonia, at maximum design capacity with federally enforceable limits applied, then compare each against 100 tons per year (40 CFR 51.165). Ammonia is the one most facilities have never calculated, and it is the one that surprises people.

In our air permitting work, ammonia is where the applicability review goes sideways. A facility with SCR or SNCR on a combustion unit, an ammonia refrigeration system, or a wastewater treatment process carries an ammonia potential to emit that was never put on paper, because attainment-area arithmetic never needed the number. Drop the threshold to 100 tons per year of any precursor and a source that is plainly minor on filterable particulate has a question it cannot answer.

The qualification test is short enough to run without calling anyone. Is the site in Sedgwick or Wyandotte County, or in one of the flagged Missouri, Oklahoma or Arkansas counties? Does it hold a Kansas Class I or Class II air permit, or a Missouri construction or operating permit? Is there a project in the next 24 months that would add 100 tons per year or more of PM2.5, SO2, NOx, VOC or ammonia? Three yeses means a nonattainment NSR applicability question is live right now. Three noes means this is a monitoring item.

What happens to a project already in permitting if designation lands?

A construction permit issued under attainment-area rules before designation is not retroactively converted. A project permitted after a nonattainment designation faces LAER and offsets at 1:1 or better (40 CFR 51.165). That difference is why the February 6, 2027 date belongs on the capital calendar, not only on the compliance calendar.

LAER is a stricter control standard than BACT and carries no cost-effectiveness safety valve. Offsets are the harder problem, because a newly designated area has no established offset market. A company needing emission reduction credits in Sedgwick County in 2028 would be hunting for a willing seller in a county that has never traded a credit. The application filed in December 2026 and the one filed in March 2027 are not the same project economically, which makes this a scheduling decision a plant manager owns.

What is the penalty for a Clean Air Act permitting violation?

Up to $124,426 per day per violation in a civil judicial action under CAA Section 113(b), for penalties assessed on or after January 8, 2025 (40 CFR 19.4). Constructing a major source or major modification without the required nonattainment NSR permit is the classic trigger, and each day of operation can count.

Two qualifiers. The January 8, 2025 figures are still the operative 2026 numbers because the annual federal civil penalty inflation adjustment was not issued this year, which we covered in the 2026 penalty freeze. And there is no enforcement initiative attached to this designation round. Designations are an administrative classification step. No primary source shows EPA making PM2.5 NSR a national enforcement priority here, and anyone telling you otherwise is selling something. The exposure is downstream and conditional on a permitting decision the company makes itself.

The Counter-Signals Are Unusually Strong

Most regulatory alerts about this round will stop at the deadlines. The more useful read is that the signals point in opposite directions at the same time, and a reader who acts on only one of them will be wrong.

Is the 9.0 microgram standard likely to survive?

Contested, and currently in force. The D.C. Circuit unanimously upheld the 9.0 ug/m3 standard in June 2026, declining the administration’s request to vacate it. Certiorari petitions are pending at the Supreme Court. EPA itself calls the standard “flawed” and is appealing the designation deadline, while stating it intends to meet it (EPA news release, 2026-10-02).

Unpack that and there are five separate counter-signals worth tracking.

The agency implementing the standard is openly hostile to it. EPA’s October 2 news release is headlined around “the Biden EPA’s Flawed 2024 Air Quality Standard” and describes it as the most stringent in history and approaching natural background levels, arguing the revision was made without adequate weighing of science or costs (EPA news release). An agency that calls its own operative standard flawed is not an agency staffing up an aggressive implementation program.

EPA is fighting the deadline it is meeting. EPA appealed the Northern District of California order on September 2, 2026, got expedited consideration in the Ninth Circuit, and has said on the record that the court’s designation timeline is unrealistic and could cause further harm. It also says it intends to designate by February 6, 2027. The designations are moving forward under protest.

The courts have gone the other way. The June 2026 D.C. Circuit ruling upheld the standard unanimously and held that off-cycle NAAQS revisions do not require a thorough review under CAA Section 109(d)(1) (Harvard EELP summary). The standard has already survived direct judicial attack. We are not naming the case or docket here because we could not verify either against a primary source.

The Supreme Court may still take it up. Certiorari petitions are pending, including one docketed at No. 26-298 (petition appendix) and a states’ petition led by Kentucky. Pending means pending. The Court has not granted, denied or scheduled anything, and any content telling you it has is ahead of the record.

Kansas is contesting the data, not the rule. The state’s recommendation attributes part of its elevated readings to a high bias in Teledyne T640X monitors during wildfire smoke episodes (Kansas recommendation). That is a representativeness argument rather than an emissions argument, and it is the strongest thing in the Kansas file. If it holds, the flag is a monitoring-method artifact rather than a change in what Wichita and Kansas City sources are putting in the air. It is also exactly the kind of argument the November 1 submission window exists for.

One more signal cuts against the assumption we hear most often. The broader deregulatory direction does not extend to this program. In the same stretch of 2026, EPA proposed rescinding the power plant greenhouse gas findings and is preparing a methane rollback, while advancing PM2.5 designations and approving state rules that narrow permit exemptions. A facility owner who reads “everything is being rolled back” and waits until March is the one buying offsets in a county with no offset market.

Net planning assumption: designation happens on schedule, and the litigation is a real reason not to commit capital to irreversible control projects before February.

What to Do Before February 6

  1. By November 1, 2026. If you hold monitoring, meteorological or modeling data bearing on whether the Wichita or JFK monitor represents your county, get it to KDHE this month for the state’s docket submission. Docket EPA-HQ-OAR-2024-0078.
  2. By November 5, 2026. File comment directly on EPA’s intended approach at regulations.gov if you have a position the state is not making for you.
  3. Now. Run a nonattainment NSR applicability review on every project in scoping. Pull potential to emit for PM2.5 and all four precursors and compare each against 100 tons per year. Ammonia first, because it is the one with no existing number.
  4. Now, if a project is close. Decide whether to file the construction permit application before designation. The attainment-area permit is not retroactively converted; the post-designation permit carries LAER and offsets.
  5. Standing. Track the monitor record annually. Design values roll on three years of data, so a flagged county can move either direction before the next round.

An applicability review covering four precursors at a facility that has never calculated ammonia is a week of engineering work, and it has to be defensible when KDHE asks how the numbers were built. iSi runs nonattainment NSR applicability determinations and potential-to-emit inventories for manufacturers in Kansas and Missouri, including the precursor calculations most sites have never had reason to run. If you have a project in Sedgwick or Wyandotte County breaking ground in the next two years, this conversation is more useful before February than after. Talk to us before you file, and we will tell you whether you have a live applicability question or a monitoring item.

Sources

Tags: