☎ (888) 264-7050
← Back to Blog Environmental

There Is No Kansas Phosphorus Number: How a Lower Arkansas TMDL Sets Your NPDES Limit

Kansas publishes no numeric stream phosphorus criterion, so a revised Lower Arkansas TMDL sets the wasteload allocation your next NPDES renewal must match.

by iSi Environmental

Kansas does not publish a phosphorus limit for its streams. A Colorado treatment works reads 1.0 mg/L total phosphorus off 5 CCR 1002-85 and plans capital around it. Kansas handles nutrients with a narrative sentence and no number, so inside a watershed that has a phosphorus TMDL, the TMDL is the number. One is on public notice now: a revised draft Total Maximum Daily Load for total phosphorus and pH covering the Little Arkansas subbasin (HUC8 11030012) and the Middle Arkansas-Slate subbasin (HUC8 11030013). Its wasteload allocations are what KDHE will write your next NPDES renewal against.

Written comments run October 8 through November 9, 2026, and KDHE holds a virtual hearing on October 26, 2026 from 11:00 a.m. to 12:00 p.m. (KDHE Notice of Hearing, Correction Notice). That notice is itself a correction: the original, published September 24, 2026, carried incorrect review and comment dates. It states no time zone for the hearing. KDHE’s office is in Topeka, which is Central Time, but the notice prints no zone, so confirm it when you register.

The stake is the arithmetic in the facility table: once EPA approves it, a permit writer is obliged to be consistent with it.

Why KDHE Reopened This TMDL, and Why the Same Error Has Appeared Before in This Basin

KDHE gives the reason: its internal review found that “the maximum design flow had been used in the wasteload allocation (WLA) calculation” for one municipal wastewater treatment plant “when the average design flow should have been applied” (KDHE Notice of Hearing, Correction Notice). The revision also updates monitoring station references, design flow information, wasteload allocation calculations, reserve and Phase I allocations, and annual loading values, without changing the TMDL approach or methodology. Every point source allocation here is a phosphorus concentration multiplied by a facility design flow, so changing the flow term moves every dependent row.

The notice itself prints no numbers. The recalculated tables are in the revised draft TMDL, posted on the KDHE Total Maximum Daily Loads program page. The currently approved version was developed November 15, 2018 and approved by EPA on February 8, 2019. The structural figures below (facility counts, class concentrations, MS4 shares) are the same in both versions. Where the revision changes a number, both values are given.

This class of error has surfaced in this basin before. A KDHE revision in the adjacent subbasins was published as “2013 Corrective Revisions to August 3, 2007 Biology TMDL,” stating that the earlier allocations “were computed using actual average flows from the point sources” while “the revised wasteloads reflect correct use of the design flows” (KDHE, Arkansas River below Hutchinson Revision). The 2013 correction moved allocations up. This one moves the affected municipal plant’s allocation down. The state has now corrected the flow term in this basin twice, this time more than seven years after EPA approval, so a recalculation is not automatically good news for your row.

What Is a TMDL Under the Clean Water Act?

40 CFR 130.7 requires a TMDL wherever technology-based effluent limits are “not stringent enough to implement any water quality standards.” It sets a loading capacity that attains the applicable narrative and numerical standards with seasonal variation and a margin of safety, then divides that capacity into wasteload allocations for permitted point sources and load allocations for nonpoint sources.

The approved Lower Arkansas document covers 584 square miles and counted 44 NPDES permitted facilities plus 11 MS4 permits across five monitoring station watersheds (KDHE TMDL, February 8, 2019 version). Its margin of safety is implicit, resting partly on allocations computed at design flow.

How Does a TMDL Wasteload Allocation Actually Become an NPDES Permit Limit?

Through 40 CFR 122.44(d)(1)(vii)(B), which requires that effluent limits “are consistent with the assumptions and requirements of any available wasteload allocation for the discharge prepared by the State and approved by EPA pursuant to 40 CFR 130.7.” A wasteload allocation is not self-executing. It reaches a permittee when a permit writer drafts the next renewal, and the allocation’s assumptions, the assigned concentration and the design flow, travel with it.

EPA documented the workflow. Every individual draft NPDES permit gets a water quality review from the same Planning and Standards Unit that develops the standards and the TMDLs, and “the permit writer then uses the strictest of the limits to draft the permit” (EPA, Kansas NPDES Program and Permit Quality Review, December 2021, pp. 22 to 23). Your allocation is one of the numbers in that comparison, and the unit that wrote it reviews your draft permit.

This is a different provision from the one governing permit process. Our post on Kansas water permits and the 30-day clock covers how a limit lands in a draft permit and how to comment inside that 30-day notice, turning on 122.44(d)(1)(ii), reasonable potential. This one covers where the number came from before the permit existed, under 122.44(d)(1)(vii)(B). If your receiving stream carries a TMDL, the limit in your draft permit was set upstream of it.

What Phosphorus Limit Will My Kansas Permit Get Under This TMDL?

The approved February 8, 2019 version builds nearly every allocation as a class concentration times facility design flow: 1.0 mg/L total phosphorus for municipal mechanical treatment plants in Phase I and 0.5 mg/L in Phase II, 2.0 mg/L for lagoon systems treating domestic waste, 4.0 mg/L for a major industrial discharger, and a nominal 0.2 mg/L for drinking water plants, most groundwater remediation outfalls, non-contact cooling water and other discharges KDHE expects to carry only nominal phosphorus (KDHE TMDL, February 8, 2019 version). The revised draft keeps the same class concentrations. Concrete ready-mix plants carry an allocation of zero, on KDHE’s finding that they are “not expected to contribute to the phosphorus loads.”

Convert your class basis to pounds per day at your design flow and compare it against today’s discharge. A plant at half its hydraulic capacity can sit inside a mass limit now and outside it at full build-out.

The nominal tier is where the surprises are. Remediation outfalls, cooling water discharges, drinking water plant backwash and ready-mix plants do not think of themselves as nutrient dischargers, and KDHE’s facility table flags several as “not required to monitor total phosphorus as condition of current NPDES permit.” A facility can hold an allocation it has never sampled against. Start pulling effluent phosphorus data now, because your own numbers are the only evidence that moves a nominal allocation.

Does Kansas Have a Numeric Phosphorus Water Quality Criterion?

No. K.A.R. 28-16-28e(d)(2)(A) protects aquatic life from nutrients by narrative criterion only, requiring that plant nutrients from artificial sources “shall be controlled to prevent the accelerated succession or replacement of aquatic biota or the production of undesirable quantities or kinds of aquatic life” (Kansas Surface Water Quality Standards, K.A.R. Article 16). The Tables of Numeric Criteria adopted at 28-16-28e(e) list dissolved oxygen at 5.0 mg/L and pH at 6.5 to 8.5, with no total phosphorus value (KDHE, Tables of Numeric Criteria).

EPA Region 7 put the consequence in operating terms: “The Kansas process does not translate narrative criteria into enforceable permit limits since technology-based limits are currently applied,” and “where TMDLs translate to nitrogen or phosphorus limits, NPDES permits contain limits conforming to the TMDL wasteload allocations (WLAs)” (EPA Kansas PQR, pp. 37 to 38). Outside a TMDL watershed, phosphorus reaches a Kansas municipal permit through the technology-based goals of the state Nutrient Reduction Plan. Inside one, the TMDL is the criterion, and the document says so: “There are no existing numeric phosphorus criteria currently in Kansas.”

Is My Facility Inside the Lower Arkansas Phosphorus TMDL Watershed?

HUC8 11030012 (Little Arkansas) and HUC8 11030013 (Middle Arkansas-Slate) are the two subbasins named in the notice. Confirm your outfall’s watershed in EPA’s How’s My Waterway at mywaterway.epa.gov, which returns the watershed assessment, impairments and permitted dischargers for a community.

Settle the permit type first. If your wastewater is retained, evaporated, land applied or hauled, you hold a state-only Kansas Water Pollution Control permit and no surface water TMDL reaches you. If your federal permit number starts with KS0, keep going. Discharging to a municipal sewer makes it a pretreatment question, though a tightened allocation at the POTW is how a new local limit reaches you.

Use EPA’s WATERS GeoViewer when the outfall sits near a subbasin boundary or the discharge enters a ditch before it surfaces. EPA built it on NHDPlus with “interactive Upstream / Downstream Search capabilities” and watershed delineation. The notice is the third route, since KDHE prints the covered segments: the named Chisholm Creek forks, the Gypsum, Spring, Dog, Bitter, Lost, Beaver, Antelope, Winser and Salt Creek segments, and the Arkansas and Little Arkansas main stem in those reaches.

When we ask a plant manager which HUC8 their outfall drains to, the usual answer is that nobody has ever asked. It takes an afternoon, and it will come up again: KDHE concentrates state TMDL effort on 16 priority HUC8s under its TMDL Vision Process, and both of these subbasins are on that list.

How Do I Comment on a Draft Kansas TMDL?

Written comments run October 8 through November 9, 2026, to Ryan Brice, KDHE Policy Planning and Standards Unit, 1000 SW Jackson St. Suite 420, Topeka KS 66612-1367, Ryan.Brice@ks.gov, 785-296-0491. KDHE states that all comments received in that window “will be considered prior to finalizing the TMDL revision” (KDHE Correction Notice). The October 26 hearing opens with a KDHE briefing, then takes public comment; accommodation requests must be made five working days in advance.

Make the comment about arithmetic. Saying the limit seems strict does nothing. Verify the design flow KDHE used for your outfall and the concentration assigned to your class, then write that the table shows X MGD, your permitted average design flow is Y MGD, and the allocation should be recalculated.

The window is not crowded. KDHE held the hearing on the underlying TMDL in Wichita on April 27, 2018 and recorded the result: “No comments were received.” Forty-four permitted facilities said nothing about a document that assigned each of them a phosphorus allocation, and the errors now being corrected went eight years unremarked.

When Does a Revised TMDL Actually Change My Permit?

At your next renewal. 40 CFR 122.46(a) provides that “NPDES permits shall be effective for a fixed term not to exceed 5 years,” which makes the date permit-specific and different for every facility in the watershed. EPA has 30 days under 40 CFR 130.7 to act on the submitted TMDL, though on a prior Kansas phosphorus TMDL upstream on the Little Arkansas, EPA comments sent KDHE through three resubmittals between December 28, 2020 and March 5, 2021 before approval (EPA Region 7 approval letter). Neither date touches an issued permit.

K.A.R. 28-16-28f(a) provides that a modification to the surface water quality standards “shall have no effect on the requirements of any existing enforceable discharge permit” absent noncompliance or a health hazard. Phase I runs from 2020 to 2040, and Phase II commences in 2041 only if instream biology has not responded, so the 0.5 mg/L enhanced nutrient removal basis is a 2041-forward proposition. Anyone selling a 0.5 mg/L emergency this year is overselling it.

EPA’s review also lists, among cases where monitoring replaced a required limit, a Kansas refinery that “had a TMDL, established WLA for phosphorus. The permit only required monitoring for phosphorus” (EPA Kansas PQR, p. 23), so a hard number is not guaranteed. GAO found that state officials reported point source TMDL targets achieved in 83% of cases against 20% for nonpoint sources (GAO-14-80). Point source targets get hit because permits are enforceable, and EPA’s 2021 review found KDHE’s permit backlog under 1%.

Work backward from your expiration date rather than the TMDL calendar: engineering feasibility two years out, capital planning 18 months out, comments inside your draft permit’s 30-day notice.

Can I Get a Compliance Schedule for a New Phosphorus Limit, and How Do I Ask?

K.A.R. 28-16-28f(c)(1) provides that a Kansas compliance schedule “shall not extend more than five years beyond the date of permit issuance,” and 28-16-28f(c)(2) allows one running past permit expiration where it is demonstrated that strict application of that cap “is not feasible due to construction scheduling constraints or other technical limitations” (Kansas WQS, K.A.R. Article 16). Federally, 40 CFR 122.47 requires compliance “as soon as possible,” with interim dates no more than one year apart.

Ask during the comment period on your draft permit, supported by the demonstration the regulation names: a construction schedule, an engineering feasibility analysis, procurement lead times. KDHE has granted them. EPA’s review records a minor industrial facility in Kansas required by a Schedule of Compliance to have an upgrade operational and meeting its TMDL-based phosphorus limit by March 31, 2022 (EPA Kansas PQR, p. 38).

What Is the Penalty for Exceeding a Phosphorus Effluent Limit in Kansas?

Federally, $68,445 per day per violation under CWA 309(d), with Class I administrative penalties of $27,378 per violation against a $68,445 cap and Class II at $27,378 per day against a $342,218 cap. Those are the amounts in effect for 2026, carried forward unchanged from 2025: the rightmost column of 40 CFR 19.4 Table 1 applies where penalties are assessed on or after January 8, 2025, and the section’s amendment history ends at that rule, 90 FR 1375. There was no 2026 adjustment.

Under Kansas law, K.S.A. 65-170d adds a civil penalty of up to $10,000 for every violation, “in addition to any other penalty provided by law,” and provides that in a continuing violation “every day such violation continues shall… be deemed a separate violation.” A nutrient limit is a monthly or rolling annual average computed from your own discharge monitoring reports, so enforcement is arithmetic on your own submittals rather than an inspection.

Do Stormwater-Only Permittees and No-Discharge Facilities Get a Phosphorus Wasteload Allocation?

Not an individual numeric one. This TMDL’s stormwater allocation runs to the 11 MS4 permits in the watershed, split by developed-land proportions of 24%, 81%, 68%, 10% and 5% and expressed as best management practices to the maximum extent practicable (KDHE TMDL, February 8, 2019 version). Industrial stormwater general permittees are not named individually in the facility table and receive no facility-specific allocation. No-discharge facilities are outside entirely, since an evaporative lagoon or a land application system has no surface water discharge to allocate against. So is the rest of the basin: Cow Creek, HUC8 11030011, has its own separate phosphorus TMDL (Kansas Register, Vol. 44 No. 31).

A zero allocation is still an allocation. It is the baseline an expansion or new outfall gets argued against, and the reserve allocation is the pool an expansion draws from. The approved version reserved 149.94 pounds per day and 54,728.10 pounds per year of total phosphorus “in anticipation of further development.” The 2026 revised draft cuts that reserve to 144.51 pounds per day and 52,746.15 pounds per year. If your five-year plan includes an expansion, the reserve that EPA finally approves decides whether it is permittable without offsetting reductions.

How Do Neighboring States Set Phosphorus Limits Differently From Kansas?

Colorado imposes nutrient effluent limits by regulation, independent of any TMDL: 5 CCR 1002-85 sets 1.0 mg/L total phosphorus as an annual median and 2.5 mg/L as a 95th percentile for existing domestic wastewater treatment works, 0.7 and 1.75 mg/L for new ones. Missouri has EPA-approved nutrient criteria for lakes only (Missouri DNR). Nebraska has none for streams, and the Title 117 provision that would have let a satisfied chlorophyll-a criterion excuse phosphorus and nitrogen exceedances is EPA-disapproved and “not in effect for CWA purposes” (Nebraska Title 117). Texas has no stream phosphorus criterion, carrying 39 approved against 36 disapproved reservoir chlorophyll-a criteria (TCEQ, 2026). Oklahoma’s 0.037 mg/L criterion applies to designated Scenic Rivers rather than statewide (Oklahoma OAC 785:45 record).

A multi-state operator cannot reuse one nutrient strategy here. A Colorado obligation arrives by rule and gets contested in a rulemaking. A Kansas obligation arrives at renewal, from a TMDL, with a design flow term that can be recalculated, and it gets contested twice: in the TMDL comment window, then in the draft permit comment. No federal rule forces Kansas to adopt a numeric stream criterion, and EPA still tracks adoption as state-by-state voluntary progress (EPA, State Progress Toward Adopting Numeric Nutrient Criteria).

What Happens After KDHE Submits the Revised TMDL to EPA Region 7?

40 CFR 130.7 requires the Regional Administrator to “approve or disapprove such listing and loadings not later than 30 days after the date of submission.” On disapproval EPA must establish the loads itself “not later than 30 days after the date of such disapproval” and issue public notice. Approval is what makes the allocation “available” for purposes of 122.44(d)(1)(vii)(B).

Approval is not a formality, as the disapproved Nebraska language shows. Contesting an allocation method afterward is harder. In American Farm Bureau Federation v. EPA the district court dismissed every challenge to the Chesapeake Bay TMDL in 2013, the Third Circuit affirmed unanimously in 2015, holding that a watershed-wide TMDL “complete with allocations among different kinds of sources” is “a legitimate policy choice by the agency,” and the Supreme Court denied certiorari on February 29, 2016 (EPA, Chesapeake Bay TMDL Court Decisions). The cheap venue closes November 9, 2026. The expensive one has a losing record.

Where to Go Next

KDHE takes public testimony on the revised draft at a virtual hearing on October 26, 2026, from 11:00 a.m. to 12:00 p.m., and accepts written comments from October 8 through November 9, 2026 (KDHE Notice of Hearing, Correction Notice). The revised draft is posted on the KDHE Total Maximum Daily Loads program page.

For general questions about NPDES permits, iSi’s environmental compliance team is available.

Sources

KDHE: the notice and the TMDL

Federal regulations (eCFR and Cornell LII)

Kansas law and water quality standards

EPA program review, federal oversight and case law

EPA watershed lookup tools

Other state standards

Tags: