The Economic Development Objectives Committee met Dec. 17 to discuss possible regulations regarding data center developments, including air quality standards, and wastewater and stormwater restrictions.
The committee again invited engineers from Olsson, an engineering and design firm based in Chesterfield, to provide insight into new data center developments at the meeting. The engineers last spoke at a Dec. 3 committee meeting about possible light, noise and water supply ordinances.
The committee, which discusses a variety of topics related to economic growth in the county, is made up of Jefferson County Council members, as well as volunteer members Chris Howard, a Cedar Hill resident seeking the Republican nomination for Jefferson County executive in 2026; Clinton McBride, government affairs director for LiUNA Local 110; and Bobby Kaye, a Festus resident and president of the Lorenzen Candle Corp. Councilmen Brian Haskins (District 1, High Ridge) and Scott Seek (District 5, Festus) were absent from the Dec. 17 meeting.
The meeting was the third the committee held to talk about formulating regulations for data centers that eventually could be developed in unincorporated Jefferson County.
A data center is a building or group of buildings that houses equipment necessary for computing, like routers, servers, switches, firewalls and storage systems.
The committee is expected to meet again at 3 p.m. Jan. 7 at the Ken Waller Memorial Building, formerly called the Jefferson County Administration Center, 729 Maple St., in Hillsboro.
At that next meeting, committee members will discuss drafting a community benefit agreement (CBA) and workforce development clause for data center developers, along with reviewing all possible regulations discussed up to that point, County Services Director Mitch Bair said.
According to the Urban Institute, a community benefits agreement promotes equitable development practices between a large developer and nearby residents. A CBA can include legally binding requirements, like hiring locally, setting wages or making contributions to certain community services. Similarly, a workforce development clause could require a developer to prioritize hiring and training nearby residents for future jobs, according to Law Insider.
After the Jan. 7 meeting, Bair said his staff will work to draft recommended language for the next few months and likely will present the draft proposal at the March 12 Planning and Zoning Commission meeting, set for 6:30 p.m. at the Ken Waller Memorial Building. The meeting will include a public hearing.
Councilman Billy Crow (District 2, Arnold) said the county has added a new section to its website with information about data centers. The section, which can be accessed by going to jeffcomo.gov and clicking on the “Data Center Information Updates” link under the county news tab, includes video recordings of past Economic Development Objectives Committee meetings regarding data centers, along with copies of Bair’s presentations on the subject. Crow said the new section will continue to grow as the conversation continues.
Councilman Bob Tullock (District 7, House Springs) said there are no current proposals from data center developers for unincorporated Jefferson County.
“This administration and County Council are simply studying the impacts of developments so that we do not have to make a rush decision,” he said. “This is, and should be, a transparent process.”
Wastewater
A large data center can use thousands of servers and advanced networking to process enormous amounts of data. The system relies on a powerful cooling system to manage heat output, which has been a cause for concern for some people living near data center complexes.
Crow said one of his constituents reached out to him concerned that data centers would use forever chemicals called PFAS in their cooling systems, which could leach into the groundwater and cause health problems for nearby residents.
If a data center uses a closed-loop water cooling system to manage excess heat, operators may treat the water with chemicals like antifreeze, corrosion inhibitors or anti-salients to protect their equipment, said Lauren Stanton, an Olsson assistant engineer who works with data centers on wastewater treatment.
She said there could be excess buildups of minerals like calcium or iron in the closed-loop cooling systems because the water is continuously running and becoming more concentrated. The wastewater from data centers would either be treated by local sewer districts, if they have the capacity for it, or by the center itself at a local treatment plant, she said.
Stanton said, in her experience, PFAS have never been seen in data center wastewater.
“(The chemicals used) are variable on the cooling technology, and typically it is trade secrets,” Stanton said. “All of these systems meet water quality standards, (and) there is a lot of sampling and water quality analysis. Before anything is discharged, there’s monitoring going on.”
Bair said wastewater treatment can be nuanced, depending on what sewer district serves the area where the data center is located. The county would need to work closely with the sewer district when a development plan is proposed to ensure the district can handle the data center’s wastewater output.
In terms of regulatory approaches, Bair said the county can mandate a data center developer submit a wastewater impact assessment prepared by a qualified engineer in the development proposal. The assessment should have information on daily and peak wastewater flows, chemical composition, including chloride and additives, temperature of water discharge and the impacts on the receiving sewer system.
If approved, the data center would be required to submit semiannual reports that include wastewater discharge volume and chemical analysis, he said.
“We want to be as cutting-edge and as progressive on these regulations as possible to ensure that we get the best product that is of no disruption to any of our adjoining neighbors, whether they’re residential or commercial,” Bair said.
Stormwater
Bair said large developments, like data centers, have lots of impervious surfaces, like rooftops and parking lots, where excess stormwater has nowhere to go, and the runoff can inadvertently flood nearby properties, causing damage.
Under proposed regulations, a data center applicant would be required to submit a stormwater management plan, along with its development plan, Bair said. The plan should show peak stormwater runoff rates at the one-year, two-year, 10-year, 25-year and 100-year storm events. Bair said the post-development rates should be less than pre-development rates, which would be a new requirement for developers in the county.
“Right now, we say (the developer) can’t generate more (than pre-development rates),” Bair said. “What we’re doing here is requiring it to come in a little bit below equal so that we’re getting less than pre-development conditions.”
Air quality
Crow said many data centers rely on backup diesel generators during power outages to remain in service.
Will Calderon, an environmental engineer with Olsson, said the Environmental Protection Agency heavily regulates generator emissions, requiring periodic reports before granting operational permits. The major pollutants from data centers are usually carbon monoxide and nitrous oxides, he said.
Bair said the county should adopt regulations requiring data centers to comply with EPA Tier 4 standards or better. Tier 4 is the strictest U.S. emissions regulations on diesel engines, the agency’s website states.
Generator testing should be coordinated with the county, Bair said, and routine testing should only occur between 10 a.m. and 4 p.m. on weekdays.
The data centers should submit a semiannual air compliance report to the county, including generator test logs, emissions data, refrigerant leak reports and any notices of violations issued by the Missouri Department of Natural Resources or the EPA, Bair said.
The county’s fine or penalty for violating air quality standards is still being determined, he said.
“We’re still working on how hard the wrist-slap is going to be,” he said. “But we’ll have something at the next meeting.”