Ogle County, Illinois Rockvale & Marion Townships Independent · unaffiliated Revised 29 July 2026

Byron's schools run on one taxpayer. A data center would make it two.

The 524 acres beside the plant are the best economic opportunity Ogle County has had since the reactors came online. Here is what it would be worth — and the terms Byron should write.

About 74% of Byron CUSD 226's revenue comes from Byron Station, under a settlement that fixes the plant's assessed value only through tax year 2027. In August 2024 the county rezoned 524 acres next door to industrial so Constellation could market the site. Nobody has applied yet. This page makes the case that Ogle County should want them to — and sets out, with sources, what the community should require in return.

What it would be worth The concerns, answered
$31.1 M
One year's property tax
What Meta's DeKalb campus was billed for 2025 — in a county next door to ours.
74%
Of school revenue
The share of Byron CUSD 226's money that comes from a single taxpayer.
2027
When that agreement ends
The settled valuation covers tax years 2022–2027. One year remains.
2,300
Megawatts next door
Firm, carbon-free, licensed to 2044 and 2046 — and being uprated now.
Schematic plan of the Byron Generating Station and the 524 rezoned acres A simplified north-up plan drawing. The Rock River runs down the west side, about two miles west of the plant. The Byron Generating Station is drawn as two circular cooling towers, a turbine hall and two containment buildings, with transmission lines running east. East of the plant, a block of 524 acres rezoned from agricultural to industrial in August 2024 is outlined in a dashed orange line and left empty, because nothing has been proposed on it. The City of Byron lies to the northeast. STATE & COUNTY ROADS ROCK RIVER PLANT MAKEUP WATER ≈ 2 MI BYRON GENERATING STATION 2 PWR UNITS · ≈2,300 MW ≈727 STAFF · LIC. 2044 / 2046 TRANSMISSION — ALREADY BUILT 524 ACRES ZONED I-1 INDUSTRIAL · READY SINCE 20 AUG 2024 ONE PERMIT FROM A SHOVEL SPECIAL USE PERMIT · PUBLIC HEARING · BOARD VOTE CITY OF BYRON POP. 3,784 · ≈4 MI NNE WATER: 3 CITY WELLS N 0 ≈1 MI
Fig. 01 — Site context, north up Drag the drawing to pan Relative positions only · schematic, not a survey
Where this page stands

We think Ogle County should welcome a data center on the 524 acres — on terms the county writes itself. This page is an argument, not a neutral survey, and you should read it that way.

It is also sourced. Every figure links back to a public record, a filing or a news report you can check, and where the evidence cuts against our conclusion — the effect of data center demand on regional power prices, the noise complaints in Aurora, the modest permanent headcount — we put the number on the page and answer it rather than leaving it out. An argument that hides its weakest point does not survive a public hearing.

Not affiliated with Constellation Energy, Ogle County, the City of Byron, or any prospective developer. No one has paid for this page.

The case, in brief

Six reasons, each of which the rest of this page works through in detail.

01

The money is real, local, and already proven next door

Meta's DeKalb campus was billed $31.1 million in property tax for 2025. Sixty-one percent of its earlier payments went to the school district, which built a new elementary school. No state incentive exempts property tax.
02

Byron is dangerously concentrated on one taxpayer

About 74% of the school district's revenue comes from Byron Station, on a settlement that expires after tax year 2027 and was preceded by a decade of appeals.
03

Almost nowhere else has all of Byron's advantages at once

2,300 MW of firm carbon-free power on the fence line, transmission already built, 524 acres already zoned, an enterprise zone already extended, and a trained industrial workforce.
04

It is years of union construction work

DeKalb's build ran five years with more than 1,000 union workers. A Byron campus means two to four years for regional electricians, pipefitters, ironworkers and operators.
05

The water fear is a design choice, and the design has changed

Air-cooled campuses use no cooling water. Closed-loop uses about what 141 homes do. Only legacy evaporative designs use millions of gallons, and Illinois stopped building those.
06

Writing the terms first is how Byron wins

Clear conditions adopted in advance protect residents and shorten a developer's timeline. On a site competing on speed-to-power, that is a selling point, not an obstacle.
Sheet01Opportunity

What is on the table, and what is still open

Everything below is on the public record. No project has been filed and no company has been named — which means the community still gets to shape the terms.

  1. Sep 2021

    Byron Station comes within weeks of shutting down

    Exelon had filed to retire the plant. Passage of the Climate and Equitable Jobs Act and its zero-emission credits kept both reactors running — and kept roughly 700 jobs and the largest line on the county's tax rolls in place. It was that close.

  2. Jun 2023

    The plant's assessed value is fixed by settlement — through 2027

    Constellation and twelve taxing bodies settled the station's equalized assessed value at $500 million for tax years 2022 through 2027, at a fixed $33,666,667 a year. The agreement also resolved appeals reaching back to 2012. It has one year left to run.

    Shaw Local, 27 Jun 2023 →
  3. 20 Aug 2024

    Ogle County rezones 524 acres and puts the site on the market

    The county board voted 18–4–1 to rezone ten parcels in Rockvale and Marion townships from AG‑1 Agricultural to I‑1 Industrial at Constellation's petition. The stated purpose was to let Constellation market its carbon-free generation and suitable land "to attract major companies capable of bringing additional jobs and tax money to Ogle County." Constellation's spokesman called it a win for taxpayers.

    Shaw Local, 21 Aug 2024 →
  4. Jan 2025

    The county board chairman confirms a data center is under consideration

    Board chairman Bruce Larson said an AI data center was being considered for the rezoned property and that "the area looks good for such a project." Byron's mayor noted that any development would raise the value of the property and the tax revenue with it. Any project still needs a special use permit and a county board vote.

    WIFR, 3 Jan 2025 →
  5. Feb 2025

    The Lee-Ogle Enterprise Zone is extended to cover the plant

    Local councils approved expanding the enterprise zone boundaries to take in the Byron plant's capacity work along with two other rural projects. The incentive framework around this site is already in place.

    Shaw Local, 5 Feb 2025 →
  6. Mar 2026

    Constellation begins an $800 million uprate at Byron and Braidwood

    New low-pressure turbines went into Byron Unit 1 during the spring outage; Unit 2 follows in autumn 2026, with high-pressure turbines in 2027 and 2028. The two plants gain 158 megawatts between them by 2028. The owner is putting capital into this plant, not winding it down — and the extra output makes the neighbouring site more attractive, not less.

    WIFR, 17 Apr 2026 →
  7. 14 Apr 2026

    Residents raise concerns; the board starts writing findings of fact

    Water and land use dominated the meeting at the old courthouse. District 6 board member Ryan Reeverts said the board would "build the findings of fact, of what these concerns are in our local community and report back to our planning and zoning committee," with a subcommittee to draft data center policy before any petition arrives. That is exactly the right sequence, and it is the single most useful thing the county can be doing now.

    WIFR, 14 Apr 2026 →
  8. 1 Jul 2026

    Illinois pauses new state data center tax incentives for two years

    Governor Pritzker directed the Department of Commerce and Economic Opportunity to stop processing new Data Center Investment Program agreements. Worth being clear about what that does and does not touch: the program exempted sales and use tax, never property tax. The local money is unaffected. Labor groups, including the Illinois AFL-CIO, called the pause shortsighted.

    Capitol News Illinois, 5 Jun 2026 →
  9. 24 Jul 2026

    Ogle County tells the state it is open to more nuclear

    Ogle County is one of nine Illinois communities that responded to the governor's call for expressions of interest in new nuclear generation, after the state lifted its long-standing moratorium on large reactors. State agencies report findings in August 2026. Long-term power demand from data centers is a large part of what makes new nuclear financeable — the two questions are linked.

    Capitol News Illinois, 24 Jul 2026 →
Sheet02Why Byron

Byron already has what the whole country is competing for

Site selection for a project like this comes down to power, transmission, land and time. Very few places in America have all four. Byron has them in one place.

Firm, carbon-free power on the fence line. Two Westinghouse four-loop reactors, about 2,300 megawatts between them, licensed to 2044 and 2046, running at high capacity factors for four decades. Constellation is spending $800 million to add 158 megawatts across Byron and Braidwood by 2028. Nothing else on the grid delivers that much power that reliably with no carbon attached.

Transmission that already exists. This is the one most people underrate. Interconnection is the single biggest source of delay in American power development right now. ComEd is holding roughly 100 data center requests totalling more than 30,000 megawatts — against an all-time system peak, after 120 years of build-out, of about 24,000 megawatts. A site that can connect to lines already in the ground is worth years, and years are the currency of this industry.

Land already zoned. 524 contiguous acres went from AG‑1 to I‑1 in August 2024. Most competing sites are still arguing about that step. Here, one special use permit stands between an applicant and a shovel.

A workforce that already does this work. 727 people run a nuclear plant here, most of them living in Ogle and Winnebago counties. IBEW locals, plumbers and pipefitters, ironworkers and operating engineers have built and maintained industrial plant in this county for forty years. Every spring refuelling outage brings hundreds more skilled trades through. The labour is not hypothetical.

Incentive machinery already extended here. The Lee-Ogle Enterprise Zone was expanded in early 2025 to cover work at the plant.

And a county that has already said yes once. The rezoning passed 18–4–1. The groundwork is done. What is left is the terms.

Site record
Location
Rockvale & Marion Twps., Ogle County
Parcels
10 (9 contiguous + 1 at 1.3 ac)
Area rezoned
524 acres
Zoning
I‑1 Industrial since 20 Aug 2024
Owner of record
Constellation Energy (~659 ac in area)
Adjacent generation
≈ 2,300 MW, 2 PWR units
Uprate underway
+158 MW by 2028
Plant staff
≈ 727
Licences expire
2044 · 2046
Enterprise zone
Lee-Ogle, extended 2025
Approval remaining
One special use permit
Fig. 02 — Why a site with existing transmission is worth yearsMegawatts
Data center requests in ComEd's queueRoughly 100 pending requests, 2026
30,000+
ComEd's all-time peak demandAfter 120 years of system build-out
24,000
Byron Station's output, on siteAlready generated, already connected
2,300
A typical new data center request, 2026Up from 150–200 MW a few years ago
700–750
New supply from the Byron & Braidwood uprateComplete 2028
158

The queue is more than the entire system's historic peak. Most of those requests will wait years for transmission that has not been built. That is the scarcity Byron is sitting on — and it is why the site has value to a developer that a cornfield with a substation ten miles away does not.

Sheet03The money

What it would actually be worth

Not projections from a developer's brochure. Tax bills that Illinois counties have already collected, from campuses already built.

Start with DeKalb, because it is forty minutes away. Meta's campus there has been operating since 2023. It was billed $31.1 million in property tax for 2025, and paid $48.5 million over 2021 to 2024. Of those earlier payments, 60.9% went to School District 428 — which used it to build Mitchell Elementary School, opened in 2025. DeKalb's mayor calls the facility "our largest economic impact in our small community." More than 1,000 union workers built it over five years.

That is the number to hold onto, because Byron Station's own settled payment is $33.67 million a year. A campus of DeKalb's scale here would very nearly double the county's largest industrial tax source.

No state incentive touches property tax. The Illinois Data Center Investment Program exempted state and local sales and use tax on equipment — never the property tax that funds schools, fire protection, the library and the roads. And since 1 July 2026 the state has paused new agreements under that program entirely, so a project starting from here would most likely be paying full freight on both.

Utility tax comes on top. Joliet expects roughly $40 million in utility taxes over thirty years alongside $310 million in property tax. DeKalb collects about $250,000 to $300,000 a year in utility taxes from its campus.

The proof, in one line

Meta's DeKalb campus paid $48.5 million in property tax across 2021–2024.

Sixty-one percent of it went to the school district.

That district opened a new elementary school in 2025.

Capitol News Illinois, May 2026

Fig. 03 — Annual property tax from Illinois data centersMillions of dollars per year
Byron Station, settled annual paymentWhat one taxpayer already provides in Ogle County
$33.7 M
Meta, DeKalb — billed for 2025Operating since 2023
$31.1 M
Joliet Technology Center$310 M over 30 years, plus $40 M utility tax
$10.3 M
CyrusOne, Sangamon CountyProjected — ≈$98 M over 20 years
$5–6 M
Aurora facilityA smaller build — scale matters, and Byron's site is not small
$1.6 M

The range is wide and we are not going to pretend otherwise — Aurora's facility yields about a twentieth of DeKalb's. Scale and assessed value drive everything. What Byron has is the power, land and transmission to attract the upper end of that range rather than the lower.

Table 01 — Where $31.1 million a year would go in Ogle County · illustrative
Taxing bodyShareIllustrative annual amountWhat it funds
Byron CUSD 22654.8%$17,040,000Schools — the district that currently draws about 74% of its revenue from one taxpayer
Ogle County10.5%$3,270,000Sheriff, courts, public health, county roads
Byron Fire Protection District7.9%$2,460,000Apparatus, staffing, EMS
Byron Forest Preserve District6.7%$2,080,000Preserves, programming
Oregon Park District6.5%$2,020,000Parks and recreation
Rock Valley College6.3%$1,960,000Community college — the pipeline for the operating jobs
All remaining districts7.2%$2,240,000Township, road district, library, extension and others

How to read this. The shares are the actual proportions in which Byron Station's settled $33,666,667 payment is divided among its taxing bodies; the six largest districts are as reported and the remainder is the balance of the settled total. Applying those shares to DeKalb's $31.1 million bill shows the order of magnitude a comparable campus would move, not a forecast. Actual shares would depend on the exact district overlaps for the specific parcels, and the actual bill would depend on assessed value. Check both against the Ogle County Clerk before quoting them.

Construction · years 0–4

More than 1,000 union workers built Meta's DeKalb campus over five years. A Byron campus means two to four years of work for regional electricians, pipefitters, ironworkers, operating engineers and concrete crews — plus hotel nights, restaurant covers, fuel, equipment rental and rentals across the region.

Operations · permanent

Large campuses run at roughly 0.2–0.3 staff per megawatt. At the 175–500 MW a site this size supports, that is on the order of 35–150 direct positions, plus contract security, facilities and maintenance. Google's 500 MW Kansas City campus projects 200 permanent jobs. In a city of 3,784, that is a significant employer.

And the 727 already here

A long-term offtake agreement is what has extended the economic life of comparable plants elsewhere — twenty years at Clinton, twenty at Three Mile Island. Byron Station's workforce is the largest single payroll in this part of the county, and demand next door makes it more durable, not less.

Sheet04Standing still

The risk Byron already carries

Doing nothing is not the safe option. It is a decision to stay concentrated on one taxpayer, on an agreement with one year left.

Table 02 — Byron Station's property tax, as settled for tax years 2022–2027
Taxing bodyAnnual paymentShareWhat it funds
Byron CUSD 226$18,442,74154.8%Schools. About 74% of the district's revenue comes from the plant.
Ogle County$3,550,37810.5%Sheriff, courts, public health, county roads
Byron Fire Protection District$2,656,6577.9%Apparatus, staffing, EMS
Byron Forest Preserve District$2,247,9896.7%Preserves, programming
Oregon Park District$2,196,7426.5%Parks and recreation
Rock Valley College$2,132,9756.3%Community college
All remaining districts$2,439,1857.2%Township, road district, library, extension and others
Total, every year 2022–2027$33,666,667100%On a settled equalized assessed value of $500,000,000

The six largest districts are as reported in the 2023 settlement coverage; the remaining line is the balance of the settled total. The 2021 equalized assessed value was $503,088,717 — the settlement was a 2.9% reduction, and it resolved appeals reaching back to 2012.

One taxpayer, one agreement, one year left. Read the table above and then read this: after tax year 2027 the plant's assessed value goes back on the table. Before the settlement it was contested nearly every year. A 2.9% adjustment on this valuation moves about a million dollars. A larger one moves a great deal more, and the district that absorbs most of it is the one that educates Byron's children.

That is not an argument against Constellation, which has been a good corporate neighbour and is currently putting $800 million into the plant. It is an argument about arithmetic. Any community that draws three-quarters of its school funding from a single assessment is exposed, and the only durable fix is a second taxpayer of comparable size.

And the plant itself was nearly lost once. In September 2021 Byron Station was weeks from retirement. State policy saved it. The pattern since has been that nuclear plants with long-term data center offtake agreements get a multi-decade revenue floor: Clinton, in DeWitt County, signed a twenty-year, 1,121 MW agreement with Meta in June 2025 that extends the plant into the 2040s and sustains its 500-plus jobs. Three Mile Island is being restarted under a twenty-year Microsoft contract. This is what security looks like for a plant like ours.

Meanwhile the neighbours are moving. Illinois has around 115 operating data centers and at least 67 more campuses planned. DeKalb, Joliet, Yorkville and Sangamon County have all landed projects and are collecting the revenue. Lockport declined. The load is coming to this state either way; the only open question is which counties end up with the tax base.

What "standing still" actually means

The 524 acres stay zoned industrial and stay empty.

The school district stays at ~74% dependence on one taxpayer.

The valuation settlement ends after tax year 2027 and the appeals resume.

The regional demand goes to DeKalb, to Joliet, to Sangamon County — and their schools get the money.

Nothing about that is neutral.

Sheet05Concerns

The concerns, answered

Every one of these has been raised in Ogle County or in an Illinois town that has already done this. None of them is silly, and none of them is unanswerable. Colours below follow the utility locate code — the paint sprayed on the ground before anyone digs.

First, what the thing actually is. One to several long, low, windowless halls — individually 400,000 to 950,000 square feet with a roofline around 40 to 60 feet. A substation and transformer yard connecting to the switchyard that already exists. A cooling plant, which is either air-cooled chillers, a closed-loop system with dry coolers, or evaporative towers. Rows of enclosed backup generators, each about the size of a shipping container, idle except during outages and scheduled tests. Fuel and fire-water storage, a security perimeter, stormwater detention, an access road built for construction traffic, and a car park smaller than the building would suggest.

Against two 495-foot cooling towers, the halls are not the tallest thing on this horizon. They are, however, wider than anything else in the township, and the honest list of what neighbours notice is: the cooling equipment, the generator enclosures, the security lighting, and — for two to four years — the construction traffic.

Each of those is a condition the county can write. That is the whole argument of this page: the impacts are known, they are bounded, and the instrument for bounding them is a special use permit that has not been granted yet.

The one question that answers five others

What cooling technology, named in the permit?

Air-cooled means essentially no cooling water, more electricity, more fan noise. Closed-loop means modest water and moderate noise. Open-loop evaporative means the large water figures people have read about.

Ask it first. Water, most of the noise question, and part of the power figure all follow from the answer — and the answer is a design decision the county can require.

Fig. 04 — Water use is a design choice, not a sizeGallons per day
Legacy open-loop evaporative cooling1 to 5 million gal/day — the design Illinois has stopped building. This bar runs off the scale.
1–5 M
The entire City of Byron, all usesEstimated by scaling Yorkville's published 800 M gal/yr for ~26,000 residents
≈ 320 k
Meta's DeKalb campus — the cap DeKalb enforcesA 2020-era evaporative design
200 k
Project Cardinal, Yorkville — closed-loop, permitted15.5 M gal/yr at full build-out — about 141 homes, or 13% of Byron's daily use
42,500
Edged campus, DeKalb — air-cooled by design560 acres, no water used for cooling at all
≈ 0

Every one of these is a real Illinois facility. They differ by more than a hundredfold — and the difference is one engineering decision, not a difference in size or company. Both large projects proposed in the DeKalb area since Meta's opened are air-cooled and closed-loop, because water is now the thing that stops a project at a county board. Byron can simply require it.

"A data center will drain our aquifer."

Raised at the April county meeting · the most common concern
Solved in the design

It is a fair question and it has a clean answer: the chart above. A modern campus here would be air-cooled or closed-loop, and at Yorkville's permitted closed-loop rate a campus would use roughly 13% of what the City of Byron already uses in a day. An air-cooled design uses none at all.

What makes this worth conditioning rather than assuming is the regulatory gap: Byron's water comes from three municipal wells, and Illinois does not require a permit to withdraw groundwater. So do not take an assurance — take a number, in the permit, with a meter behind it. Any serious developer will accept that, because they are building to that standard anyway.

Put this in the permit
  • The cooling technology, named and binding, with substitutions requiring re-approval
  • A hard daily and annual withdrawal cap with financial penalties — Yorkville's ordinance is the working Illinois model
  • Metering with quarterly public reporting, regardless of what the state does
  • A baseline survey of nearby private wells before construction, plus monitoring wells and drawdown triggers, at the applicant's expense
  • A make-whole obligation if a neighbouring well fails within a defined radius and period

"It's 550,000 gallons a day, like the one in DeKalb."

A figure circulating locally since spring
Wrong number, wrong generation

The number the City of DeKalb actually enforces on the Meta campus is 200,000 gallons a day. Higher figures circulate; the enforceable one is the cap.

More to the point, DeKalb's cooling decision was locked in around 2020, and the industry has moved since. The two large campuses proposed in the DeKalb area afterwards are air-cooled and closed-loop. Byron would be choosing from the 2026 menu, not the 2020 one.

What this rests on
  • Shaw Local, 10 Jul 2026 — DeKalb's 200,000 gal/day cap and open-loop design
  • WIFR, 14 Apr 2026 — the figure as raised at the Ogle County meeting
  • Shaw Local, 26 Nov 2025 — the air-cooled DeKalb proposal

"The state doesn't regulate data center water at all."

True — so Ogle County should

Correct, and we are not going to pretend otherwise. The POWER Act — which would have required quarterly water reporting to the Illinois State Water Survey, 200-foot setbacks from drinking water supplies and homes, and cooling at least as efficient as closed-loop — died without a floor vote on 31 May 2026. Illinois still requires no permit to withdraw groundwater.

That is an argument for local conditions, not for refusal. Ogle County's special use permit can adopt the POWER Act's own standards word for word. A county that does that gets stronger protection than the failed bill would have delivered — and gets it now.

What this rests on
  • Circle of Blue, 2026 — POWER Act provisions and its failure
  • Capitol News Illinois, 5 Jun 2026 — the governor's seven reform principles
  • Illinois DNR — no permit required for withdrawal alone

"It'll drive up my electric bill."

Real regionally · different here

Here is the strongest version of the objection, stated plainly. PJM capacity prices — the market that pays generators to be available — went from $28.92 per megawatt-day for 2024/25 to $269.92, $329.17, $333.44 and $325 for the four delivery years since. PJM's own Independent Market Monitor attributed about 70% of one year's increase, roughly $9.3 billion, to data center demand. Capacity is around a fifth of a ComEd bill.

Now the part that matters for Byron. That price signal is driven by data centers joining the queue and adding load to a grid that has to build for them. A co-located project here does not do that: it does not sit in ComEd's 30,000-megawatt interconnection queue, and it does not force new distribution build. New supply is being added on this site — 158 megawatts of uprate by 2028, and long-term demand is precisely what finances the next one.

And the alternative on offer is not "less demand." Illinois has 67 or more campuses planned. That load arrives in PJM whether or not Ogle County participates. Byron saying no does not lower anyone's bill; it moves the tax base to another county.

The larger price risk runs the other way. If Byron Station ever came off the system, removing about 2,300 megawatts of baseload from the ComEd zone would move wholesale prices far more than reallocating a slice of it ever could. In 2021 that was four weeks away.

Put this in the permit
  • The applicant pays its own interconnection and transmission upgrade costs
  • New generation or storage brought with the load, not taken from the existing pool
  • A curtailment or interruptibility commitment during grid stress
  • Annual public reporting of actual peak and average demand

"Is 'behind the meter' just a way around the rules?"

Being defined, in public

No — it is being regulated in the open right now. On 18 December 2025 FERC found PJM's existing behind-the-meter rules "no longer just and reasonable" and directed PJM to create new Firm and Non-Firm Contract Demand transmission services for co-located load, with a compliance filing due 16 February 2026.

The premise of that order is that co-located load does use the grid and should pay for what it uses. That is the right outcome and it is good for Byron: it means any project here arrives with a defined, federally-supervised cost allocation rather than an argument. Ogle County should simply require the applicant to disclose its interconnection structure as a condition of the permit.

What this rests on
  • FERC order on co-located load in PJM, 18 Dec 2025
  • PJM compliance filing, due 16 Feb 2026
  • Citizens Utility Board, 15 Jul 2026 — capacity prices by delivery year

"Will this put the plant's power out of reach for the rest of us?"

The plant grows with the demand

Byron's output is already sold into PJM — that is true and worth understanding. What changes it is new supply, and new supply is what long-term demand pays for. Constellation is adding 158 megawatts across Byron and Braidwood by 2028 in an $800 million programme. At Clinton, the Meta agreement came with a 30 MW uprate and a licence renewal.

And look one step further out: in July 2026 Ogle County told the state it is interested in hosting new nuclear generation, after Illinois lifted its moratorium on large reactors. Committed, creditworthy, multi-decade demand is the thing that makes new nuclear financeable. A data center here is not a competitor for the plant's power — it is the customer that pays for more of it.

What this rests on
  • WIFR, 17 Apr 2026 — the $800 M uprate, +158 MW by 2028
  • Meta / Clinton, Jun 2025 — 1,121 MW, 20 years, plus a 30 MW uprate
  • Capitol News Illinois, 24 Jul 2026 — Ogle County's new-nuclear letter of interest

"It'll be loud, and we'll be stuck with it."

Write the limit first

Aurora is the cautionary tale, and it is worth telling accurately. Residents there measured up to 80 dB near facilities that came online in 2025, described the sound as "white noise on steroids," and the city adopted 56 dB daytime and 46 dB overnight property-line limits in March 2026 — after the buildings were running.

Two things make Byron's position different. First, the rezoned parcels sit roughly four miles from town on farmland, not against a subdivision. Second, and more important, Ogle County has the chance to set the limit before anything is built, which is the difference between a design requirement and a retrofit.

One technical point worth insisting on: much of the sound is low-frequency, which travels farther and is poorly captured by a standard A-weighted meter. A dBA-only ordinance is the mistake to avoid.

Put this in the permit
  • Separate day and night limits at the property line, not an average
  • A low-frequency standard — dBC or one-third-octave bands — alongside dBA
  • An independent ambient baseline measured before construction, so "no change" can be proved
  • Continuous monitoring at the applicant's expense, published
  • A complaint-and-cure process with a deadline and a consequence

"It'll change how the place looks."

Scale it, screen it, condition it

Some of that is true and there is no point denying it: a hall of 400,000 to 950,000 square feet is a large building. It is also, at 40 to 60 feet, a fraction of the height of the cooling towers that have defined this skyline since 1985 — and it sits on ground already zoned heavy industrial, next to the largest industrial neighbour in the county, rather than scattered across the township grid.

What neighbours actually notice is rarely the roofline. It is roof equipment, generator enclosures, the substation and the security lighting at night. All four are conditionable, and screening and lighting standards are routine in Illinois industrial siting.

Put this in the permit
  • Maximum height, maximum lot coverage, and minimum setbacks from every property line and public road
  • Full cut-off, dark-sky compliant exterior lighting with a night curfew on non-security fixtures
  • Berming and a landscape buffer with a survival and replacement guarantee, not a planting plan alone
  • Roof and yard equipment screened, with screening specified in the permit

"Construction will tear up our roads."

Bond it before the first truck

This is the impact residents most reliably underestimate beforehand and most reliably resent afterwards, and it is real: two to four years of heavy haul traffic on township and county roads that were not designed for it, plus dust, plus a workforce arriving faster than local housing absorbs it.

It is also the impact with the most established remedy. Haul route agreements with road damage bonds are standard practice for Illinois industrial siting and they work — provided they are signed before the first permit is issued rather than negotiated after the first road fails. The same workforce surge that strains hotels also fills them, for years.

Put this in the permit
  • A designated haul route agreement with the township and county road districts
  • A road damage bond sized to full reconstruction, posted before mobilisation
  • Pre- and post-construction road condition surveys by a third party
  • Restricted construction hours and mandatory dust suppression
  • A named site contact and a published complaint line that a human answers

"All those diesel generators will foul the air."

Tier 4 from 1 December

Backup power for a campus this size means dozens of generators. They are idle most of the year and tested on a schedule; the emissions question is about runtime, not nameplate.

Illinois has just tightened this. Under the Clean and Reliable Grid Affordability Act, from 1 December 2026 most Illinois data center air permit applications must propose emergency diesel engines meeting US EPA Tier 4 — the strictest tier — where Tier 2 or Tier 3 previously sufficed. Gas-fired units face a comparable standard. A project permitted here would be cleaner than anything built in this state before it.

The one thing genuinely worth prohibiting is a facility running generators for economic reasons during grid stress, which turns a backup system into a part-time power plant. Say so explicitly in the permit.

Put this in the permit
  • Total generator count and aggregate nameplate stated, with expansion requiring re-approval
  • Tier 4 or better in writing, independent of the state deadline
  • Testing restricted to weekday daytime hours, with a published annual schedule
  • An annual runtime cap, reported
  • An explicit prohibition on running generators for grid-economic reasons — outages only

"It takes good farmland out of production for good."

0.1% of the county · already rezoned

The parcels were AG‑1 before 20 August 2024 and are I‑1 now. That change is done, and rezoning is permanent in a way people should be clear-eyed about.

The scale is worth holding in view: 524 acres is about eight-tenths of a square mile — roughly one-tenth of one percent of Ogle County, or a bit over three quarter-sections. And it is concentrated on one contiguous block already adjacent to the county's largest industrial neighbour, rather than dispersed across the township grid. Concentrating industrial use next to industrial use is how good county zoning is supposed to work.

What this rests on
  • Shaw Local, 21 Aug 2024 — AG-1 to I-1, ten parcels, 524 acres
  • U.S. Census — Ogle County land area, for the percentage

"It'll wreck my property value."

The studies don't support the fear

The research that exists does not find the effect people fear. A University of Rochester analysis found little measurable effect on nearby home prices. A George Mason study in Northern Virginia found homes closer to data centers sold for more. An Integra Realty Resources study using Zillow data across four Indiana counties from 2021 to 2026 found no significant difference in value or appreciation within a mile and a half.

Being straight about the limits: none of those is Ogle County, the George Mason work also found new data centers slowed local price growth, and none of them isolates the handful of homes closest to a noisy facility. Those specific homes are protected by the noise, lighting and buffer conditions in B‑1 and B‑2 — not by a study.

What this rests on
  • University of Rochester — effect on nearby home prices
  • George Mason University, 2025 — Northern Virginia sale prices and growth
  • Integra Realty Resources — four Indiana counties, 2021–2026

"All that pavement will flood the neighbours and the river."

Standard engineering

Several hundred acres of roof and pavement changes how fast rainfall leaves a site. Standard Illinois practice is detention sized so post-development runoff does not exceed pre-development rates, and that standard works when it is designed and inspected properly.

The failure mode in practice is almost never the finished design — it is the construction phase: bare soil, a heavy storm, and silt in the ditches and eventually the Rock River. Erosion control is the thing to bond and inspect.

Put this in the permit
  • Detention designed to pre-development release rates for the full range of design storms
  • A bonded erosion and sediment control plan covering every construction phase
  • Third-party inspection during construction, paid by the applicant
  • Post-construction monitoring of receiving ditches and tributaries
Sheet06The terms

The terms of a good deal

Everything the last sheet concluded, in one place. Print it, bring it, and ask which items an applicant will accept in writing. Every one of these has been imposed by an Illinois local government in the last two years.

Why writing these first is the pro-development move, not the obstructive one. A developer choosing between sites is buying certainty and speed. A county with a clear, adopted, published set of conditions tells them exactly what the project must be and how long approval will take. A county with nothing written tells them to budget for eighteen months of discovery and a contested hearing.

Ogle County began compiling findings of fact in April 2026 and discussed a subcommittee to draft policy before any petition arrives. That is the right sequence and it deserves support. A project that will accept these terms is a project worth having. A developer who will not is one Byron should let walk.

Water

  • Cooling technology named in the permit; substitution requires re-approval
  • Hard daily and annual withdrawal caps, with financial penalties
  • Metering plus quarterly public reporting
  • Baseline survey of private wells within a defined radius, before construction
  • Monitoring wells and drawdown triggers, applicant-funded
  • Make-whole obligation for any well that fails within radius and period
  • Setback from municipal wellhead protection areas

Power & the grid

  • Disclosure of the interconnection structure — co-located, grid-served, or both
  • Applicant pays its own interconnection and transmission upgrade costs
  • Curtailment or interruptibility commitment during grid stress
  • New generation or storage brought with the load, not taken from it
  • Annual public reporting of actual peak and average demand

Noise, light & siting

  • Separate day and night limits at the property line
  • Low-frequency standard (dBC or one-third-octave) alongside dBA
  • Independent pre-construction ambient baseline
  • Continuous monitoring, published, applicant-funded
  • Complaint-and-cure process with a deadline and a consequence
  • Maximum height, lot coverage and setbacks
  • Dark-sky compliant lighting with a night curfew
  • Berming and buffer planting with a survival guarantee

Air & generators

  • Generator count and aggregate nameplate fixed in the permit
  • Tier 4 or better in writing, independent of the state deadline
  • Testing limited to weekday daytime, schedule published
  • Annual runtime cap, reported
  • No generator operation for grid-economic reasons

Land, roads & runoff

  • Detention to pre-development release rates
  • Bonded erosion and sediment control, all phases
  • Third-party construction inspection, applicant-funded
  • Designated haul route agreement with the road districts
  • Road damage bond sized to full reconstruction, posted before mobilisation
  • Pre- and post-construction road condition surveys
  • Restricted construction hours and dust suppression
  • Decommissioning plan and removal bond for end of life

Jobs & community

  • Committed permanent headcount and wage floor, in the permit
  • Local and regional hiring commitments, with reporting
  • A project labor agreement or equivalent for the construction phase
  • A community benefit agreement with the host districts
  • A workforce pipeline with Rock Valley College
  • No local property tax abatement without an offsetting commitment
  • Named site contact, published complaint line, annual compliance report
Sheet07Elsewhere

What the towns that already did this got

Illinois has around 115 operating data centers and at least 67 more campuses planned. Several are close enough to drive to. Their results — good and bad — are the best evidence Byron has.

Table 03 — Illinois data centers, as reported
PlaceLocal moneyWaterWhat Byron should take from it
DeKalb — Meta
Operating since 2023		 $31.1 M billed for 2025
$48.5 M, 2021–24		 Open-loop evaporative; city cap 200,000 gal/day The model outcome. 60.9% of the tax went to School District 428, which built and opened Mitchell Elementary in 2025. 1,000+ union workers over a five-year build. The mayor calls it the city's largest economic impact. The lesson on water: the city set an enforceable cap, and it holds.
DeKalb — Edged
Proposed, 560 ac		 — Air-cooled — no water used for cooling Proof that the water question is a design choice, settled on the same soil as the county's evaporative campus. This is the 2026 standard Byron should specify.
Yorkville — Project Cardinal — Closed-loop; 42,500 gal/day at full build, penalties above 71,400 Copy this ordinance. A cap, a penalty and a number in the text — the cleanest working model of an enforceable Illinois water condition.
Joliet — Technology Center
795 ac, approved		 $310 M over 30 yrs
+ $40 M utility tax		 ≈ 54.75 M gal/yr; litigation alleges 100–150 k gal/day Large revenue, and an active lawsuit over water. Both belong in the same sentence — and the lawsuit is what happens when the number is not settled in the permit up front.
Sangamon County — CyrusOne $5–6 M / yr
≈ $98 M over 20 yrs		 — Recently approved. The revenue figures are projections, not receipts — ask for the assessment method, not the headline.
Aurora ≈ $1.6 M / yr — The cautionary tale. Sustained noise complaints — residents measured up to 80 dB — and the council adopted 56 dB day / 46 dB night property-line limits in March 2026, after the fact. A smaller build, in a built-up area, with the rules written last. Byron can invert all three.
Table 04 — Nuclear plants that signed long-term data center agreements
DealAnnouncedCapacityWhat it did for the plant
Amazon × Susquehanna
Talen Energy · Pennsylvania		 Mar 2024 up to 960 MW Campus purchased outright for about $650 million. Became the test case that produced FERC's December 2025 order clarifying the rules for everyone since.
Microsoft × Three Mile Island
Constellation · Pennsylvania		 Sep 2024 ≈ 835 MW A twenty-year agreement bringing a retired reactor back as the Crane Clean Energy Center, backed by a $1 billion federal loan.
Meta × Clinton
Constellation · DeWitt County, Illinois		 Jun 2025 ≈ 1,121 MW Twenty years, plus a 30 MW uprate and licence renewal, at an Illinois plant that faced closure pressure much like Byron's in 2021 — extending it into the 2040s and sustaining 500-plus jobs. DeWitt County's board chair on the plant: "They've been a great economic partner."

One honest distinction: Clinton signed a power purchase agreement. A plant can sell power to a data center 300 miles away without a single truck arriving in Ogle County — and Byron would get none of the property tax. The 524 acres are about a building here, with the tax base here. That is the version worth wanting.

What to do about it

The rezoning is finished. The terms are not — and that is the part still worth showing up for.

Ogle County began compiling findings of fact on community concerns in April 2026 and discussed forming a subcommittee to draft data center policy before any petition arrives. Support that. A county that adopts clear conditions in advance protects its residents and shortens a developer's timeline at the same time.

Agendas, minutes and meeting times for the county board, the Planning & Zoning Committee and the Zoning Board of Appeals are posted by Ogle County Planning & Zoning. Verify times before you go — one complaint raised in April was that weekday-morning meetings are hard for working residents to attend, and that is itself something a board can change.

Sheet08Q&A

Questions people ask

Short answers, with the uncertainty left where it belongs.

Is a data center actually coming to Byron?

Unknown. The land is zoned for it, Constellation rezoned the parcels explicitly to market the site, and the county board chairman said in January 2025 that an AI data center was under consideration. But no application has been filed and no company has been named. That is not a reason to wait — it is the window in which the community gets to set the terms.

What would it actually be worth to my school district?

Meta's DeKalb campus was billed $31.1 million in property tax for 2025, and 60.9% of its 2021–2024 payments went to School District 428 — which built and opened a new elementary school in 2025. Applying Byron Station's own district shares to a bill of that size would put roughly $17 million a year into Byron CUSD 226. Treat that as an order of magnitude rather than a forecast, and check it with the county clerk.

Doesn't the state give data centers a tax break that cuts us out?

No. The Illinois Data Center Investment Program exempted state and local sales and use tax on equipment. It never exempted property tax, which is where essentially all the local money is. And since 1 July 2026 the state has paused new agreements under the program for two years, so a project starting now would most likely have neither exemption.

Why is the 2027 date such a big deal?

Because Byron CUSD 226 draws about 74% of its revenue from one taxpayer, and the settlement fixing that taxpayer's assessed value at $500 million — and its payment at $33,666,667 a year — covers tax years 2022 through 2027. After that the valuation is renegotiable. Before the settlement it was appealed nearly every year, and the 2023 agreement resolved appeals reaching back to 2012. A second large industrial taxpayer is the most direct way to reduce that exposure.

How many permanent jobs, honestly?

Fewer than the construction number, and we are not going to blur them. Large campuses run at roughly 0.2 to 0.3 permanent staff per megawatt, so a 175–500 MW project implies on the order of 35 to 150 direct positions plus contract security, facilities and maintenance. Google's 500 MW Kansas City campus projects 1,000 construction jobs and 200 permanent. The construction phase is the bigger employment story — 1,000-plus union workers over five years at DeKalb — and it is temporary. Both numbers are worth having in a city of 3,784.

Would my well go dry?

Not with an air-cooled or closed-loop design, which is what current projects use. A closed-loop campus at Yorkville's permitted rate would use about 13% of what the City of Byron already uses in a day; an air-cooled one uses none for cooling. Because Illinois requires no groundwater withdrawal permit, the protection has to come from the county's permit — a named cooling technology, a metered cap, baseline surveys of nearby private wells, drawdown monitoring, and a make-whole obligation. Ask for all five.

Would this raise my electric bill?

Data center demand has pushed PJM capacity prices up across the region, and that is a real effect we are not going to argue with. But it is driven by projects joining the interconnection queue and forcing new build. A co-located project here does not join ComEd's 30,000 MW queue, and new supply is being added on this site — 158 MW of uprate by 2028. The load is coming to Illinois regardless; 67 or more campuses are planned. Byron declining moves the tax base, not the demand. And the far larger price risk would be losing 2,300 MW of baseload from the ComEd zone altogether, which was four weeks away in 2021.

How loud would it be at my house?

That depends entirely on what the county writes down. Aurora's residents measured up to 80 dB — and Aurora set 56 dB day / 46 dB night property-line limits after the buildings were running, in a built-up area. Byron's parcels are roughly four miles from town, and Ogle County can set the limit first. Insist on separate day and night limits, a low-frequency standard alongside dBA, a pre-construction baseline, and applicant-funded monitoring.

Is the plant at risk if nothing is built?

Not immediately — Constellation is spending $800 million on uprates and the licences run to 2044 and 2046. But it was weeks from closing in September 2021, and the plants that have secured their next two decades did it with long-term data center agreements: Clinton, Three Mile Island, Susquehanna. Demand next door is what makes a plant like Byron's durable, and it is also what makes the new nuclear Ogle County told the state it wants financeable.

Who wrote this, and what do they want?

This is an independent civic page, not affiliated with Constellation Energy, Ogle County, the City of Byron, or any prospective developer, and nobody has paid for it. It takes a position: Ogle County should welcome a data center on the 524 acres, on terms the county writes itself. Everything on the page is sourced, including the facts that cut against that position. Corrections are welcome and will be logged as revisions.

Sheet09Sources

Sources & method

Where every number came from, what we estimated ourselves, and what we would change our minds about.

No Byron-specific figures for megawatts, water, acreage or jobs exist, because no application exists. Where this page gives a range for Byron it is inferred from named comparable projects and stated as an inference. Three figures are our own arithmetic and are marked as such: the City of Byron's daily water use, scaled from Yorkville's published annual figure and population; the megawatt range a 524-acre site plausibly supports, derived from published campus land-to-power ratios; and the illustrative tax distribution in Table 01, which applies Byron Station's actual district shares to DeKalb's actual tax bill. Check all three.

What would change our conclusion. An applicant that refuses to name its cooling technology, will not accept a metered water cap, will not post a road bond, or will not commit to a night-time noise limit at the property line. On this page's argument, a project that will not accept the terms in Sheet 06 is not the project Byron should take.

Local facts — the vote, the acreage, the tax settlement, the uprate — come from Ogle County reporting and public records. State and market facts come from Illinois agencies, Capitol News Illinois, PJM auction results and the Citizens Utility Board. Where a figure is contested, both versions appear.

  1. Shaw Local / Ogle County News. Ogle County Board OKs rezoning 524 acres near Byron nuclear plant. 21 August 2024. Vote tally, parcels, townships, zoning classes, Constellation's stated purpose.
  2. Shaw Local / Ogle County News. Byron nuclear station, 12 taxing bodies reach settlement on EAV. 27 June 2023. Settlement terms, per-district distributions, 2021 EAV, appeals resolved back to 2012.
  3. WIFR. Community prepares for possible AI data center at Byron nuclear plant. 3 January 2025. Board chairman and mayor statements; special use permit requirement.
  4. WIFR. Ogle County community gathers to share concerns on data centers. 14 April 2026. Resident concerns, findings-of-fact process, subcommittee proposal, meeting times.
  5. WIFR. Byron Nuclear Plant completes first phase of multi-million dollar upgrade project. 17 April 2026. Uprate scope and schedule, 158 MW, $800 M.
  6. Shaw Local / Sauk Valley. Dixon council OKs enterprise zone expansion. 5 February 2025. Lee-Ogle Enterprise Zone boundary extension covering the Byron plant.
  7. Capitol News Illinois. How do data centers benefit the places where they're built? Local mayors give mixed reviews. May 2026. DeKalb, Aurora, Joliet and Sangamon County figures; Meta's $48.5 M and Mitchell Elementary.
  8. Capitol News Illinois. Gov. JB Pritzker to suspend tax breaks for data centers. 5 June 2026. DCIP pause, ComEd queue figures, stakeholder positions including the Illinois AFL-CIO.
  9. Capitol News Illinois. These 9 Illinois communities say they're interested in new nuclear facilities. 24 July 2026. Ogle County's letter of interest; state timeline.
  10. Shaw Local. Questions arise over data centers' water use; Illinois considers mandating water-efficient cooling systems. 10 July 2026. Yorkville, Joliet and DeKalb water figures; cooling technology comparison.
  11. Circle of Blue. Illinois fails to pass landmark act requiring responsible data center energy and water use. 2026. POWER Act provisions and failure; Illinois campus counts.
  12. Citizens Utility Board. Sustained high PJM capacity prices ramp up urgency for data center reform. 15 July 2026. Capacity prices by delivery year; share of the ComEd bill.
  13. Federal Energy Regulatory Commission. Order on co-located load in PJM, 18 December 2025, and PJM compliance filings, 2026. Behind-the-meter rules; Firm and Non-Firm Contract Demand service.
  14. Illinois Department of Commerce & Economic Opportunity. Data Center Investment Program guidelines and annual reports. Investment threshold, job and wage floors, exemption scope and term.
  15. Illinois Environmental Protection Agency / Clean and Reliable Grid Affordability Act. Backup generator emissions standards for data center air permit applications, effective 1 December 2026.
  16. Illinois Department of Natural Resources; Illinois State Water Survey. Water supply regulation — no permit required for withdrawal alone; Byron-area aquifer units.
  17. U.S. Nuclear Regulatory Commission, dockets 50-454 and 50-455; Byron Station licensing record. Reactor type, capacity, licence expiry, cooling and Rock River withdrawal, employment.
  18. American Nuclear Society, Nuclear Newswire. Constellation rezoning petition coverage, 2024. Total Constellation acreage in the area.
  19. The Hill; WAND-TV; Citizen Portal. Aurora data center noise ordinance and resident measurements, March 2026.
  20. Bisnow; Integra Realty Resources; George Mason University; University of Rochester. Property value studies near data centers, 2025–2026.
  21. Data center land and staffing benchmarks: published campus acreage-to-capacity ratios and operations staffing ratios per megawatt, 2025–2026 industry reporting.
  22. U.S. Census Bureau. 2020 Decennial Census. Byron, Illinois population 3,784; Ogle County 51,788 and land area.