The discharge & the receiving water
Dilution at the design low flows, and the burden the receiving water already carries.
A real impact study screens the project's discharge against the assimilative capacity of the receiving stream — how much pollutant that stream can take before it breaches a criterion — at the stream's cited design low flows. The design flow matches the criterion type: chronic aquatic-life dilution at the 7Q10, and acute dilution at the 1Q10, which is the sharper single-day design low flow. It also sets that discharge beside what the county's TRI reporters already release. These are screening bands. They are not a permit determination.
The dilution screen · baseline
| Discharge → receiving water | Design 7Q10 | Discharge | Chronic | Credited | Acute (1Q10) | Evidence |
|---|---|---|---|---|---|---|
| Sidney WWTP→ Great Miami River (Sidney WWTP outfall, RM 128.68) | 24 cfsOhio EPA "Fact Sheet for NPDES Permit Renewal, City of Sidney WWTP, 2022" (permit 1PD00009*SD, application OH0027421), Table 14 "Instream Conditions and Discharger Flow", printed p.32 — GMR above Sidney, 7Q10 annual 24.0 cfs, USGS gage #03261500, 1927-2021 data. Read from the source PDF text layer (data/documents/oepa/sidney/1PD00009.c43b66fd.pdf, 0-based page 80), digits clean; structured read at data/extracted/oepa/sidney/1PD00009.npdes.yaml. | 11 cfs | 2.22:1 · tight | — | 1.79:1 · tight | [verified] |
0 of 1 receiving reach fails a dilution band at design low flow. The effluent-credited ratio counts the permitted effluent already in the reach (WS-15); a cited 1Q10 of 0 cfs is a stream that runs dry at design low flow — no acute capacity at all.
What the county's TRI reporters already release
| Facility | City | RSEI score |
|---|---|---|
| KLINGER THERMOSEAL INC | SIDNEY | 14,721,455.6 |
| MECHANICAL GALV-PLATING CORP | SIDNEY | 440,747.9 |
| PEERLESS FOOD EQUIPMENT LLC | SIDNEY | 413,866.6 |
| HONDA DEVELOPMENT & MANUFACTURING OF AMERICA LLC - ANNA E | ANNA | 400,317.3 |
| EMERSON CLIMATE TECHNOLOGIES LLC | SIDNEY | 347,131.9 |
Any new discharge lands on top of this baseline — the point of reading the two halves together. The full ranked inventory and its reading caveats are in the RSEI annex.
The record behind this chapter
What this chapter stands on: the records it reads, the inputs its modeled figures rest
on, and the reference data behind its baselines — the same pages the record screens
serve, not a second copy. A figure the record does not support stays [open] and links nothing.
- 1PD00009.c43b66fd.pdfOhio EPA
- City of Sidney WWTPPermits
- Sidney "Sidney Data Center Campus" / Project Rey — the City's incentive, service and development instruments, as executedIncentive packages
- City of Sidney Resolution No. 26-26 — authorizing the City Manager to enter into a Water and Wastewater Service Agreement with Amazon Web Services, Inc., passed 2026-04-27Local legislation
- Permits6 records
- RSEI toxic-release inventory (EPA)Reference dataset