Greenfield (TAP139489 - TURKEY HILL)
GreenfieldSt. Clair County, Illinois · MISO
At a glance
Greenfield (TAP139489 - TURKEY HILL) is a greenfield datacenter candidate site in St. Clair County, Illinois, scoring 51.4/100 DC Readiness — 87th of 100 scored sites in the county. Its nearest substation is TAP139489. It sits in the MISO grid region and the SOUTHWESTERN ELECTRIC COOP INC - (IL) service territory, where interconnection has averaged 4.8 years from request to operation. GridCensus catalogs 100 MW of candidate capacity here.
Power & interconnection
Speed to power
Deep queue and long historical waits — plan for a multi-year interconnection timeline and engage the utility early.
Connectivity
Site characteristics
Risk & environment
Location context
Regulatory climate
New-DC state tax exemptions suspended for 2 years (from Jul 2026).
Incentive detail: Enterprise Zone sales tax exemption; High Impact Business designation for $12M+ DC investments.
Site location
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How does Greenfield (TAP139489 - TURKEY HILL) compare with other sites in St. Clair County?
Greenfield (TAP139489 - TURKEY HILL) ranks 87th of 100 scored candidate sites in St. Clair County. Its 51.4/100 is roughly in line with the county average of 54.4. It is roughly in line with the Illinois average of 54.3 and roughly in line with the national average of 53.2.
Against the Illinois average, its strongest sub-score is natural hazard (65 vs 63) and its weakest is power availability (30 vs 37). Power and speed to power each carry 20% of the composite score, fiber 12%, water 7% and hazard 6%.
How close is Greenfield (TAP139489 - TURKEY HILL) to power, fiber and other datacenters?
The nearest mapped substation, TAP139489, is the closest grid connection point on record and operates at 138 kV. For connectivity, the nearest internet exchange facility is Netrality St. Louis - 900 Walnut at 18.3 miles. 10 fiber providers report service at the location in FCC broadband data. The closest operating datacenter on record is TierPoint, 18.5 miles away.
What are the flood, water and hazard risks at Greenfield (TAP139489 - TURKEY HILL)?
At the county level, FEMA's National Risk Index rates St. Clair County "Relatively High".
Full DC Readiness breakdown
All 13 weighted sub-scores (0–100) behind the composite DC Readiness score.
Nearby comparable sites
Other scored datacenter candidate sites in St. Clair County, ranked by DC Readiness.
| Site | Type | Voltage | Capacity | Queue wait | Score |
|---|---|---|---|---|---|
| OZ St. Clair | Greenfield | — | — | 4.8 yrs | 64.4 |
| TURKEY HILL | Substation-Adjacent | 345 kV | 600 MW | 4.8 yrs | 63.8 |
| Belleville Landfill Project | Brownfield | 138 kV | 13 MW | 4.8 yrs | 63.7 |
| TAP156135 | Substation-Adjacent | 138 kV | 100 MW | 4.8 yrs | 59.1 |
| UNKNOWN157809 | Substation-Adjacent | 138 kV | 100 MW | 4.8 yrs | 59.1 |
| PORTER RD | Substation-Adjacent | 138 kV | 100 MW | 4.8 yrs | 59.0 |
| S BELLEVILLE | Substation-Adjacent | 138 kV | 100 MW | 4.8 yrs | 58.8 |
| E BELLEVILLE | Substation-Adjacent | 138 kV | 100 MW | 4.8 yrs | 58.8 |
Greenfield (TAP139489 - TURKEY HILL): common questions
What is the DC Readiness score of Greenfield (TAP139489 - TURKEY HILL)?
Greenfield (TAP139489 - TURKEY HILL) scores 51.4/100 on the GridCensus DC Readiness scale, rated fair. It ranks 87th of 100 scored sites in St. Clair County. The St. Clair County average is 54.4 and the Illinois average is 54.3.
What is the nearest substation to Greenfield (TAP139489 - TURKEY HILL)?
The nearest mapped substation is TAP139489, at 138 kV. GridCensus catalogs 100 MW of candidate capacity for the site.
Which electric utility serves Greenfield (TAP139489 - TURKEY HILL)?
SOUTHWESTERN ELECTRIC COOP INC - (IL) (cooperative) holds the retail service territory that contains the site.
What grid region is Greenfield (TAP139489 - TURKEY HILL) in?
Greenfield (TAP139489 - TURKEY HILL) is in the MISO region. Projects interconnecting there have averaged a 4.8-year wait from queue request to operation.
How far is Greenfield (TAP139489 - TURKEY HILL) from an internet exchange?
The nearest internet exchange facility is Netrality St. Louis - 900 Walnut, about 18.3 miles away; 10 fiber providers report service at the location.
Related pages
About this data
Source: GridCensus composite of HIFLD transmission and substation data, EIA, FEMA National Risk Index, FCC broadband data, PeeringDB and ISO interconnection queues, as published October 10, 2026 — GridCensus refreshes it monthly. See the methodology for how records are matched, cleaned and scored.
Cite as: GridCensus, “Greenfield (TAP139489 - TURKEY HILL), St. Clair County, IL”, https://gridcensus.com/datacenter-sites/illinois/st-clair-county/greenfield-tap139489-turkey-hill-199f268a (data as of October 10, 2026).
Dataset updated . Screening estimates derived from public data sources.
Figures are screening estimates derived from public infrastructure data. Catalogued capacity reflects theoretical candidate capacity, not deliverable or committed interconnection. Confirm all values with the utility, ISO, and on-the-ground due diligence.
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Every site and score for Greenfield (TAP139489 - TURKEY HILL), St. Clair County is free to browse. Pro adds Watchtower on 25 sites, alerts when new candidate sites, datacenters or interconnection-queue requests appear in your markets, score and capacity history, and CSV export. Enterprise adds team seats, weekly data files for all 147,272 sites, the REST API and an MCP server for AI tools.