Toxics and the corridor — the river the campus joins

A #233 extension narrative. Like end-use-and-workloads.md and defense-nexus.md it is hand-assembled analysis over cited records, and it ends at a question it cannot close. Every statement carries its register: [verified] (read from a cited record or a public gauge), [inference] (a labeled derivation), [open] (a question the record does not answer), [reference] (an outside-published spec or method). One discipline governs this page: EPA’s RSEI is a modeled, comparative screening score — it ranks who releases the most, relative to each other; it is not a measurement of what is in the water. The river-flow figures are hard [verified] records; the toxic concentrations are order-of-magnitude [inference]; the verdict the reader most wants — is it too much — stays [open], and the page is built to say so.

The plainest way to say what this report is: the campus does not discharge into a clean river. At design low flow the Ottawa River leaving Lima is 93% treated effluent [verified], and the corridor it runs through already carries the county’s heaviest industrial toxic load. The campus adds to that loop — a process discharge and a stormwater outfall — at two of its weakest points. None of that, by itself, is a violation or a finding of harm. What it is, is the receiving environment: the thing any new discharge lands in. Reading it honestly means stating what the record measures, what it only screens, and where the answer simply isn’t in the corpus.

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the river is already effluent

Start with the water, because the water is the part the record nails down. The Lima municipal loop is one closed system on two rivers: the city draws from the Auglaize/Ottawa, treats it, runs it past municipal and data-center demand, and returns it through wastewater plants to the Ottawa River. At design low flow — the drought-season 7Q10 the state itself uses to write discharge permits — the receiving streams carry almost nothing.

Routing the cited headwater low flows and the documented discharges through the confluence network, the loop’s streams carry, in total, only 1.01 cfs of natural low flow (Ottawa 0.2 + Dug Run 0.78 + Pike Run 0.03) [verified: document]. The three county wastewater plants alone add 8.82 cfs of treated effluent — 8.7× the streams’ entire natural low flow, with no data center in the picture. Add the campus’s own documented 3.87 cfs FM-2 process discharge (routed through Lima’s sewer and WWTP) and the Ottawa leaving Lima reaches 93% treated effluent [verified: docs/HYDROLOGY.md §1] — and that is a conservative floor, because Lima’s own large municipal plant has no cited design flow in the corpus and isn’t even counted.

The seasonal floor is worse than an average suggests. The Ottawa’s 1Q10 is 0 cfs — the mainstem literally dries, in 21% of years on the public USGS record [inference: derived from NWIS 04187100]. The river that receives the corridor’s discharges is, at its lowest, not a river diluting effluent. It is the effluent.

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the corridor’s toxic load

Onto that already-effluent reach the corridor stacks an industrial toxic burden, and here the discipline has to be exact. The measure is EPA’s RSEI — the Risk-Screening Environmental Indicators, a modeled, population-weighted, unitless score built to triage: to rank which dischargers are largest relative to each other. It is explicitly not a risk estimate, a dose, or a concentration [reference: EPA RSEI]. Used for what it is, it tells you where to look first.

Of the 12 RSEI facilities that release toxics to water in Allen County, 3 sit on a near-undiluted reach of the Ottawa corridor [verified: docs/HYDROLOGY.md §1]:

INEOS USA LLC — RSEI score 23,483,255, the corridor’s largest; top chemical acrylonitrile, ~99% cancer-weighted.
Lima Refining Co. — RSEI 1,899,615; the heaviest reported water release (~1.75M lb cumulative), top chemical benzene. It is the only one whose receiving water — OTTAWA RIVER — is independently ECHO-cited [verified: ECHO, NPDES OH0002623].
PCS Nitrogen Ohio LP — RSEI 532,740; top chemical formaldehyde.

Placing each at the same cited 7Q10 and assuming its annual reported pounds fully mix in that drought flow yields a screening concentration — INEOS ~66 mg/L, Lima Refining ~165 mg/L, PCS Nitrogen ~274 mg/L. Read those numbers for exactly what they are. They are a coarse [inference: derived] order-of-magnitude screen: annual pounds, instantaneously and fully mixed at the 7Q10, no mixing zone, no decay, no volatilization. They are not measured concentrations, not permit limits, and not what a sample of the river would show. And for two of the three, the receiving water itself is inferred from the corridor’s coordinate cluster, not independently cited. What survives that discipline is narrow and real: three large toxic dischargers sit on a reach the same record shows is near-undiluted at low flow.

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the campus joins it twice

The campus is not outside this corridor; it enters the loop at two points, and both are documented.

The first is the FM-2 process discharge — the 3.87 cfs already counted above, routed through Lima’s sewer and the municipal WWTP to the Ottawa. That is the discharge that takes the leaving river to 93% effluent.

The second is quieter and lands worse. The campus’s stormwater leaves the site by a constructed BOSC Storm Outfall that discharges to Pike Run [verified: SWP3, Ohio EPA eDoc 4091286] — the loop’s most flow-starved tributary (7Q10 0.03 cfs), the one the screen already shows running undiluted under the American Bath plant. The SWP3 documents construction disturbance (5.71 ac), not a continuous low-flow discharge, so it is recorded as a receiving-water fact, not added to the mass balance. But the geography is the point: of every stream in the loop, the campus’s stormwater path finds the one with the least water in it.

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the same pounds are a Lake Erie budget

The corridor’s discharges don’t just strain a local stream. The Ottawa flows to the Auglaize and on to the Maumee — Lake Erie’s largest tributary and the driver of its western-basin harmful algal blooms. The 2023 Maumee Watershed Nutrient TMDL (Ohio EPA, US-EPA-approved) assigns each individually permitted discharger a spring-season total-phosphorus cap, and the plants the low-flow screen flags as undiluted are the same permits carrying those caps [verified: docs/HYDROLOGY.md §2] — Lima WWTP 4 metric tons/yr, Shawnee II 0.75, American-Bath 0.37, American II 0.3, Lima Refinery 0.6, 64.1 metric tons across the grouped category. So the local dilution failure sits inside a basin-scale budget: at design low flow these effluents are near-undiluted, and every pound of phosphorus in them is metered against a Lake Erie nutrient cap.

And the timing compounds both. The mainstem’s dry floor falls in the May–October window where evaporation exceeds rainfall — so the largest loads meet the smallest assimilative capacity exactly when the river is lowest.

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where this stops

Set it all down together: a river that is 93% effluent at low flow, three of the county’s largest toxic dischargers on the same near-dry reach, a campus that adds a process discharge and routes its stormwater onto the most starved tributary, and a phosphorus budget that runs to Lake Erie. The reader will want the next sentence to be a verdict — that is too much, the assimilative capacity is exceeded. The record does not support that sentence, and this page will not write it.

It cannot, for reasons that are themselves the finding:

RSEI is modeled, not measured. The screening concentrations are an order-of- magnitude triage, no mixing or decay, two of three receiving waters inferred. They rank the dischargers; they do not measure the river [reference: EPA RSEI].
The compliance record is absent. No Discharge Monitoring Reports — the actual permit-compliance measurements — are in the corpus for these outfalls. Only design flows and cited low-flow statistics [open].
No one has sampled the water here, in the record. The corpus carries no ambient water-column concentrations, no toxicity bioassays, no benthic survey for the Ottawa, Pike Run, or Dug Run [open].

What the corridor establishes is a screening-level question, sharply posed: does the modeled toxic load plus the documented effluent plus the campus’s two discharges exceed what this river can actually assimilate at design low flow? Everything needed to raise that question is [verified] or honestly [inference]. Everything needed to answer it — measured concentrations, DMR compliance data, an instream fate-and-transport model — is not in the record. The honest end is the open one: the campus is joining a river already at its limit by every screen we can run, and the measurement that would settle it has not been taken, or not been produced.

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sources

The 93% effluent finding, the routed mass balance, the per-stream low-flow screen, the RSEI corridor table, and the Maumee TMDL phosphorus caps — HYDROLOGY.md §1–§2 (watermark.hydrology, generated; figures tagged [verified]/[inference] at source)
The cited 7Q10 / 1Q10 / 30Q10 and their Ohio EPA fact-sheet provenance — data/reference/hydrology/low-flow-7q10.yaml; independent reproduction from USGS NWIS 04187100 (Ottawa River at Lima)
The RSEI inventory, scores, and water releases — data/reference/rsei/ (inventory + toxic-discharge-screen.yaml); the method caveat — data/reference/rsei/README.md
The mapped corridor (campus, JSMC, WWTP NPDES points, the RSEI overlay) — data/site/bundle/feeds/geo/rsei.geojson, geo/wwtp.geojson; the watershed map at gis-map.md
The campus stormwater outfall to Pike Run — the roundabout/outfall SWP3, Ohio EPA eDoc 4091286 (operator George J. Igel & Co., engineer WSP USA)
The NPDES inventory and ECHO receiving waters — data/reference/echo/ (maumee-wwtp.potw.yaml, the Maumee NPDES inventory)
The demand-side frame this sits beside — ECONOMICS.md, the-load-and-the-grid.md