# N05_E18 · 1985 EPA master plan, CSO, and municipal-treatment bridge

**Research date:** 2026-08-12 UTC  
**Sector:** `N05_E18` — canonical 24 × 24 grid cell, 37.5–45.0° N and 90–75° W; human anchor Merrillville, Indiana  
**Time band:** 1950–2000, with primary report anchors in 1984–1985 and a contemporary 2026 machine-readable cross-check  
**Research status:** bounded bridge note; not a completed sector-period record  
**Model status:** `provisional_quadrant: unresolved`

## Research question

What does the page-verified 1985 U.S. EPA Region V master plan add to the N05_E18 record about engineered flow, water-quality measurement, municipal treatment, combined-sewer-overflow control, and institutional response in the Grand Calumet River / Indiana Harbor Canal system?

This run continues the Great Lakes pilot at the next unresolved path named in the existing notes. It adds a distinct primary technical report extraction and a current machine-readable EPA facility-list cross-check. It does not duplicate the existing 1984 USGS flow/diel-survey note or the 1989–1991 Archive.org technical-report notes. It does not download or score ICIS-NPDES DMR rows.

## Spatial and temporal crosswalk

The EPA report covers the Grand Calumet River / Indiana Harbor Canal basin in northwest Indiana, centered on Gary, Hammond, East Chicago, and Whiting. That footprint is inside, but not coextensive with, fixed cell `N05_E18`. The report is a basin/system plan, not a complete 7.5° × 15° cell record. The current ECHO workbook supplies facility points and HUC-12 labels, not a historical reconstruction of the 1985 system.

- Primary report publication: January 1985; report identifier `EPA-905/9-84-003C`; 160 scanned pages.
- Historical observations below use printed-page numbers from the report, not PDF scan indexes.
- Contemporary cross-check retrieved 2026-08-12; current listing fields are not treated as 1985 observations.
- Historical and modern evidence are related but not equivalent: the report describes conditions and institutional actions in a defined period, while the workbook describes a current EPA facility-list structure.

## Raw observations

### A. 1985 EPA Region V master plan

1. The report describes the GCR/IHC as a narrow, heavily industrialized watershed with water-quality and aquatic-habitat problems, high concentrations of conventional, non-conventional, and toxic pollutants in sediment and overlying water, and sharply reduced biological activity. **Provenance:** printed p. i, Preface. **Observation type:** institutional technical description; no cell-wide concentration is derived.
2. The report states that no surface-water gaging stations existed on the GCR/IHC at the time. It gives estimated average flows of **16 cubic feet per second (cfs)** in the West Branch and **880 cfs** in the East Branch, based on a cited 1982 EPA source. It states that East Branch flow was sustained by high volumes of Lake Michigan cooling water pumped by U.S. Steel and that **more than 90%** of GCR/IHC flow originated as treated municipal and industrial wastewater, industrial cooling/process water, and stormwater runoff. **Provenance:** printed p. 2-11, scan/OCR page 23. **Observation type:** historical report quotation/summary; values are basin-branch estimates, not measurements of the fixed cell.
3. The report says water quality had improved over the prior five to ten years, attributing improvement to improved treatment plants, stormwater/sanitary-sewer separation, POTW maintenance, industrial wastewater treatment, and water reuse. It also cautions that lower industrial effluent loads partly reflected plant closings, relocation of discharge points, and early-1980s production cutbacks. **Provenance:** printed p. 2-8, scan/OCR page 27. **Observation type:** source interpretation retained as reported; the report does not isolate causal shares.
4. The report compares a minimum dissolved-oxygen value at East Branch station `GCR37`: **1.8 mg/L in 1977** versus **7.2 mg/L in 1983**, based on Indiana State Board of Health monthly sampling records. It states that no values below the **5.0 mg/L** standard were reported at that station from 1978–1984, while warning that sampling frequency may not capture true minima. **Provenance:** printed p. 2-8, scan/OCR page 27. **Units:** mg/L dissolved oxygen. **Missingness/caution:** station-specific, monthly sampling; not a branch-wide or cell-wide mean, and not proof of system-wide recovery.
5. The report describes a January 1984 sediment program with ten grab samples across the GCR/IHC; eight stations were averaged for a comparison with 1980 core-composite data, excluding two stations below milepoint 2.6 in the Indiana Harbor Canal. It reports approximate 1984 averages for lead and zinc at **35%** and **36%**, respectively, of the 1980 averages. **Provenance:** printed p. 2-18, scan/OCR page 37. **Observation type:** report-level comparison. **Missingness/caution:** differing sampling locations, techniques, analytical protocols, local clean-sediment/scour effects, and excluded stations limit direct trend inference.
6. The report explicitly says that differences in sampling design and technique limit further comparison; some contaminants appeared improved while the reverse appeared for others. It says a reliable representative sediment analysis and priority-zone identification required a carefully designed sampling program. **Provenance:** printed p. 2-20, scan/OCR page 39. **Observation type:** source-stated uncertainty; not converted into a score.
7. For East Chicago, the report lists a 1977 NPDES permit with limits for ammonia, BOD, chlorides, fluoride, cyanide, oil and grease, phenol, phosphorus, suspended solids, pH, and sulfate. It states that the facility had chronic violations, that a 1982 court order required operational and sludge-handling improvements, and that September 1984 non-compliance included ammonia, phenol, cyanide, fluorides, chlorides, sulfates, oil and grease, BOD, and total suspended solids. **Provenance:** printed pp. 3-18–3-19, scan/OCR pages 105–106. **Observation type:** historical permit/compliance record summarized by EPA.
8. For Gary, the report lists a 1977 NPDES permit and a 1983 consent judgment requiring staffing/training, equipment restoration, additional treatment and sludge facilities, improved operation and maintenance, new effluent limits, and pretreatment compliance. It states that September 1984 non-compliance involved ammonia and that earlier problems included raw-sewage bypass concerns. **Provenance:** printed pp. 3-19–3-20, scan/OCR pages 106–107. **Observation type:** historical permit/compliance and legal-response record.
9. For Hammond, the report describes a 1979 permit, permit expiration in 1983 while remaining in force, CSO-related contamination concerns, sludge-lagoon overfilling, a 1980 EPA civil action, sewer separation and a five-mile force main completed in 1981, and September 1984 compliance with permit conditions. It also states that all three POTWs were operating under expired permits that remained in force while new permits awaited completion of the Indiana wasteload-allocation study. **Provenance:** printed p. 3-20, scan/OCR page 107 and printed p. 3-21, scan/OCR page 108. **Observation type:** historical institutional-response record; no effectiveness score assigned.

### B. Current machine-readable EPA facility cross-check

The current EPA ECHO workbook **POTWs with Combined Sewer Overflows Facility List** was downloaded 2026-08-12. The selected rows identify the following present-day facility/listing fields:

| Permit | Facility | HUC-12 | Latitude | Longitude | Type/status field | Listed CSO count |
|---|---|---|---:|---:|---|---:|
| `IN0022977` | Gary Wastewater Treatment Plant | `071200030406` | 41.606528 | -87.384083 | POTW / M | 13 |
| `IN0023060` | Sanitary District of Hammond | `071200030407` | 41.622194 | -87.513083 | POTW / M | 20 |
| `IN0022829` | East Chicago Municipal Sewage Treatment Plant | `071200030407` | 41.619010 | -87.480750 | POTW / M | 3 |

**Raw-data interpretation:** these are current facility-list fields in an EPA workbook. They are not 1985 CSO frequencies, discharge volumes, compliance rates, or cell-wide infrastructure densities. The workbook does not supply a historical time series in this run.

## Source interpretation

The 1985 plan presents the GCR/IHC as a coupled engineered-water and institutional system. Flow was strongly shaped by pumped cooling/process water and wastewater inputs; monitoring was limited by the absence of surface-water gaging stations; and water-quality improvements coexisted with industrial contraction, treatment investment, sewer separation, court orders, permit enforcement, and unresolved sediment uncertainty.

The report’s station-level dissolved-oxygen and sediment comparisons show why this project must preserve measurement design and provenance. The 1.8-to-7.2 mg/L comparison is a local station observation with a sampling-frequency caveat. The lead/zinc percentages compare different sampling programs and are explicitly limited by method and location differences. Neither can be generalized to the fixed cell or converted into a single water-quality score.

The historical permit section records uneven institutional response: East Chicago and Gary had documented compliance and operational problems, while Hammond was reported in compliance for September 1984 amid broader CSO and sludge-management litigation. This is evidence of differentiated institutional conditions and responses, not a classification of a population or a proof that legal intervention produced durable adaptation.

The current ECHO rows confirm that the three municipal systems remain represented in a machine-readable regulatory facility inventory and provide exact contemporary identifiers useful for a future DMR crosswalk. They do not establish continuity of facility boundaries, permit versions, outfall counts, discharge magnitude, or compliance between 1985 and the present.

## Derived observations and scores

No Macro-Culture constraint, adaptive-capacity, energy, water, infrastructure, population, or quadrant score was calculated.

| Candidate input | Raw evidence | Model limitation |
|---|---|---|
| Engineered-water dependence | Historical report gives 16 cfs West Branch, 880 cfs East Branch, and >90% wastewater/cooling/process/stormwater origin | Basin estimates based partly on cited earlier work; no cell-wide flow denominator |
| Water-quality constraint | Station-specific DO comparison; sediment lead/zinc comparison; report-stated toxic/sediment problems | Non-equivalent stations/programs, incomplete coverage, and sampling caveats |
| Institutional response | POTW permits, court orders, sewer separation, treatment upgrades, enforcement, WLA process | Presence/action is not measured effectiveness or adaptive capacity |
| Contemporary facility structure | Three current EPA workbook rows with HUC-12, coordinates, and CSO-list counts | Current listing is not a historical series and is not a full fixed-cell inventory |

**Derived score:** not calculated.  
**Adaptive-capacity judgment:** unresolved.  
**`provisional_quadrant`:** unresolved; model output only, never an archival fact.

## Confidence and missingness

```yaml
confidence:
  historical_report_authority: high
  page_level_extraction: medium-high
  geographic_fit_to_N05_E18: medium
  temporal_fit_to_1950-2000: high
  modern_facility_rows: high
  historical_modern_comparability: low-medium
missingness:
  - geographic_match_uncertain
  - historical_measure_not_available
  - period_match_uncertain
  - source_exists_not_digitized: underlying HydroQual study and cited 1974/1986/1987 records
  - searched_no_result: no DMR rows downloaded in this run
  - conflicting_sources_possible: source-specific flow and sampling definitions
  - not_applicable: no score and no quadrant
```

The 1985 report was available as a scanned EPA NEPIS PDF and required OCR; page references above were checked against the printed-page labels and OCR page images. OCR is treated as an extraction limitation, not as permission to repair unreadable values by inference.

## Unresolved gaps and next search path

1. Retrieve the underlying 1984 HydroQual wasteload-allocation study and its appendix; the EPA master plan confirms it was used in the WLA process but does not replace it.
2. Retrieve Snow’s 1974 Calumet-area investigation, Indiana’s 1986 fixed-station strategy, and the cited 1987 USGS water-resources record from the 1991 source register.
3. Define a non-duplicative ICIS-NPDES DMR extraction window for `IN0022977`, `IN0023060`, and `IN0022829`; preserve permit version, outfall, parameter, units, limits, reporting period, qualifiers, and NODI codes. Do not treat missing or non-receipt codes as zero.
4. Crosswalk the historical GCR/IHC basin and station points to the fixed `N05_E18` rectangle and existing WBD/NLDI anchors; preserve partial coverage and boundary uncertainty.
5. Pair the historical station records with modern WQP/USGS observations only after aligning analyte, method, detection limit, station geometry, season, and sampling design.
6. Continue the nine-sector Great Lakes pilot before deriving any formula output or `provisional_quadrant`.

## Machine-readable contemporary cross-check

The current EPA ECHO workbook **POTWs with Combined Sewer Overflows Facility List** was downloaded as an XLSX artifact on 2026-08-12. It lists the three relevant NPDES facilities and exposes structured fields for `NPDES_ID`, facility name/address, HUC-12, latitude, longitude, facility type, major/minor status, and CSO count. The rows are a current facility/listing crosswalk, not historical discharge measurements and not a cell-wide inventory.

| NPDES ID | Facility | HUC-12 | Latitude | Longitude | Facility type | Major/minor | Listed CSOs |
|---|---|---|---:|---:|---|---|---:|
| `IN0022829` | East Chicago Municipal Sewage Treatment Plant | `071200030407` | 41.61901 | -87.48075 | POTW | M | 3 |
| `IN0022977` | Gary Wastewater Treatment Plant | `071200030406` | 41.606528 | -87.384083 | POTW | M | 13 |
| `IN0023060` | Sanitary District of Hammond | `071200030407` | 41.622194 | -87.513083 | POTW | M | 20 |

**Artifact URL:** <https://echo.epa.gov/files/POTWs%20with%20Combined%20Sewer%20Overflows%20Facility%20List.xlsx> (retrieved 2026-08-12).


## Provenance register

| ID | Source / identifier | Date | Evidence used | Page/item or URL | Tier | Confidence |
|---|---|---:|---|---|---|---|
| H1 | U.S. EPA Region V, *Master Plan for Improving Water Quality in the Grand Calumet River/Indiana Harbor Canal*, `EPA-905/9-84-003C`, NEPIS item `200075QV` | 1985-01 | Historical flow estimates, wastewater dependence, DO and sediment comparisons, municipal permits/compliance, CSO and legal responses | https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=200075QV.PDF; printed pp. i, 2-8, 2-11, 2-18–2-20, 3-18–3-21; scanned PDF pp. 3, 23, 27, 37, 39, 105–108 | A | high for report statements; medium-high for OCR extraction |
| M1 | U.S. EPA ECHO, *POTWs with Combined Sewer Overflows Facility List* | retrieved 2026-08-12 | Current machine-readable rows for the three municipal facilities | `https://echo.epa.gov/files/POTWs%20with%20Combined%20Sewer%20Overflows%20Facility%20List.xlsx`; selected rows by permit ID | A | high for listed fields; not historical |
| M2 | U.S. EPA ECHO, ICIS-NPDES DMR Summary and Data Element Dictionary | retrieved 2026-08-12 | DMR archive naming, fiscal-year structure, and field definitions for next extraction | https://echo.epa.gov/tools/data-downloads/icis-npdes-dmr-summary | A | high for data-structure documentation; no rows extracted |
| P1 | Existing project note, `2026-08-12-N05_E18-1970-1991-grand-calumet-water-quality-archive-epa-bridge.md` | 2026-08-12 | Non-duplication ledger and prior source-register leads | Local project file; related Archive.org/DTIC items `DTIC_ADA206507`, `DTIC_ADA236435` | Project record | high for prior-work boundary |

## Bottom line

The page-verified 1985 EPA plan adds a defensible 1950–2000 bridge: the Grand Calumet / Indiana Harbor system depended heavily on engineered and wastewater-derived flow; historical measurement was spatially and methodologically limited; station-level dissolved oxygen and sediment comparisons showed apparent improvement with explicit caveats; and municipal treatment, legal, sewer, permit, and wasteload-allocation responses were uneven across Gary, Hammond, and East Chicago. A current EPA machine-readable facility list supplies exact identifiers for the next DMR extraction. These observations remain local and source-specific. No cell-wide score, adaptive-capacity judgment, or `provisional_quadrant` is justified.