Mayor Cara Spencer Signs Board Bill 49

Mayor Cara Spencer today signed Board Bill 49 (BB 49) into law, codifying a nation-leading municipal regulatory framework for data center development in the City of St. Louis. Sponsored by 1st Ward Alderwoman Anne Schweitzer and passed unanimously by the Board of Aldermen (BoA), the landmark legislation updates the municipal Zoning Code to establish clear land-use rules, strict environmental and noise controls, and enforceable community protections.

"This bill is the result of an intensive, lengthy, and collaborative effort to tackle a complex issue head-on," said Mayor Cara Spencer. "By bringing together city departments, aldermanic partners, neighborhood advocates, labor, and environmental leaders, we have established a nation-leading benchmark. We are proving that St. Louis can attract high-tech economic opportunity while prioritizing sustainability, protecting neighborhood health, and guaranteeing public accountability."

The signing marks the culmination of a year-long collaborative process initiated under Mayor Spencer's Executive Order 92 and BoA Resolution 111. The order replaced outdated zoning classifications regulating data centers under generic "office" or "warehouse" categories with an interim regulatory framework, while directing city departments to construct a permanent legislative framework. Over the past year, city leaders from the Planning & Urban Design Agency, Zoning Office, Water Division, and Sustainability Office worked closely with members of the BoA, community residents, labor leaders, environmental advocates, and industry stakeholders to craft a comprehensive policy.

"By putting the city's first comprehensive regulations in place, we've made it clear that St. Louis not only expects new data centers to run on renewable energy, but also that developers invest their resources to expand clean energy infrastructure and to innovate in ways that protect the air we breathe and the water we drink," said BoA President Megan Green. "I want to thank the many, many residents who shared their views and stayed engaged throughout this process; it's because of them that our city now has some of the strongest data center regulations in the country."

As data center infrastructure expands nationally, St. Louis residents have voiced crucial questions and concerns regarding potential impacts on neighborhood quality of life, public health, energy and water resource demands, heat generation, and local electrical grid stability. BB 49 directly addresses these concerns through best-in-class, legally binding safeguards:

• Strict Buffers and Neighborhood Protections: Data centers are strictly prohibited in all residential districts and local neighborhood commercial zones. Where permitted with conditions in industrial and commercial zones, mandatory buffer setbacks safeguard sensitive uses:
  • Micro Data Centers (<10,000 sq. ft., <5 MW): Minimum 150-foot setback.
  • Standard Data Centers (10,000-250,000 sq. ft., 5-30 MW): Minimum 300-foot setback.
  • Major Data Centers (>250,000 sq. ft. or ≥30 MW): Minimum 600-foot setback from residential homes, schools, public parks, light rail stations, and transit centers.
• Comprehensive Noise Mitigation: Operational noise levels cannot exceed 5 decibels (dBA & dBC) above pre-application baseline studies at property lines. All noisy equipment, including cooling units and backup generators, must be fully enclosed within sound-dampening structures.
• Resource & Grid Safeguards: Water-intensive evaporative cooling systems are prohibited. Developers must enter into binding agreements with the St. Louis Water Division, fund hydraulic model studies, and pay any system impact fees. Operations cannot begin without explicit, written grid capacity verification from the electric utility provider.
• Leading Renewable Energy Mandates: Standard and Major facilities are required to start operations at a minimum of 25% renewable energy, scaling to 50% by Year 5, and achieving 100% renewable energy by Year 10. Noncompliance triggers steep financial penalties (up to 300% of the market rate for regional bundled Renewable Energy Credits), preventing grid strain and mitigating thermal heat impacts through mandatory Cool Roofs, Green Roofs, or solar installations.

The bill's protections set a best-in-class model for cities nationwide by pairing rigorous environmental standards with transparent public governance and enforceable community benefits. St. Louis is among the first major U.S. municipalities to pass a comprehensive, dedicated data center zoning code that proactively regulates energy sourcing, noise impact, and land-use compatibility for data center developments.

While enforcing rigorous protections, Board Bill 49 establishes a predictable, transparent development path that generates meaningful economic value for the city:

• Guaranteed Community Engagement and Public Impact Agreements: Developers of Major Data Centers are required to advertise and host public community meetings with advance notice sent via mail and email to neighboring property owners and neighborhood organizations. Furthermore, developers must sign binding Public Impact Agreements with the City to fund neighborhood infrastructure upgrades, public safety resources, and local welfare improvements.
• Local Job Creation and Economic Growth: Major applications must document anticipated construction and permanent operational workforce numbers, supporting union labor and strengthening the city's tax base through local earnings tax and property tax revenue.
• Urban Architectural Integration: Buildings along downtown commercial frontages must dedicate at least 50% of ground-floor space to active uses (such as office, retail, or amenities), meet architectural window transparency standards, and screen all loading docks and utility infrastructure from public view.

Board Bill 49 also responsibly keeps major commercial investments and construction jobs viable in the city. Provisions call for mandatory economic impact reporting, where developers seeking a conditional use permit must submit a third-party report detailing construction and permanent jobs to assess local labor opportunities. The bill also provides that project details and economic considerations from community meetings must be made publicly available, enabling labor and residents to verify hiring numbers for accountability.

While many jurisdictions rely on reactive, piecemeal restrictions or retrofitting existing general industrial codes, Board Bill 49 establishes a proactive, nation-leading template. Key elements that position St. Louis at the forefront of municipal data center policy include:

• First-in-Nation Renewable Scaling Framework: Unlike typical land-use codes that ignore utility demand, BB 49 legally binds facilities to a 10-year transition toward 100% renewable power, setting a new national benchmark for municipal grid protection.
• Tiered Buffer and Noise Thresholds: By categorizing facilities into Micro, Standard, and Major data center tiers, the ordinance establishes precise, distance-based setbacks (up to 600 feet) and low-frequency noise caps (5 dBA & dBC over baseline) to safeguard urban neighborhoods.
• Comprehensive Water Safeguards: Banning water-intensive evaporative cooling prevents local water depletion, addressing an environmental vulnerability seen in data center hubs across the U.S.

The City extends sincere gratitude to all partner agencies, aldermanic sponsors and partners, regional stakeholders, and resident advocates whose extensive feedback, technical expertise, and dedication were instrumental in shaping this legislation. BB 49 takes effect immediately.

Partner Statements and Quotes

Alderwoman Anne Schwietzer (Bill Sponsor)

"Data centers cause harm to people and the environment. They must be strongly regulated While not perfect, this bill will limit data center development in St. Louis to the most appropriate locations for their size and impact, ensure projects are thoroughly scrutinized through a comprehensive and public application process, and require data centers over five megawatts to operate with 100% renewable energy by year ten. This bill is a big step forward for our city."

Alderwoman Sonnier (Bill Co-Sponsor)

"Data centers are coming to cities across the country, and as our city decides our approach, our strongest considerations should center public health, public safety, affordability, environmentalism and the needs of our residents; these are the values that both myself and Alderwoman Schweitzer prioritized as we worked in Board Bill 49.

While this bill isn't perfect and doesn't prevent all harms. It does mean that any approved data center will have clear rules, expectations and standards that won't be up to the decision or feelings of any one individual or entity. I give my deepest gratitude to the many residents, advocates, planning and sustainability staff that have shared their thoughts, expertise, and time with me over the past year, and who showed up continually despite their frustrations."

James Owen (Executive Director, Renew Missouri)

"Ensuring data centers are responsible and sustainable corporate neighbors in St. Louis is of paramount concern for civic leaders and citizens alike. The renewable energy requirements put forward by the leadership of sponsors Alds. Schweitzer and Sonnier as well as the support of Mayor Spencer - some of the strongest in the nation - will strike a balance between economic development and the City's own clean energy goals. Renew Missouri is proud of its staff's involvement with assisting these leaders on forging a path forward that will serve as a model for all cities."

Jake Hummel (President, Missouri AFL-CIO)

"This bill strikes a vital balance by bringing high-tech economic investment to St. Louis while ensuring our city's working families aren't left behind. This landmark legislation will create good-paying local union construction and operational jobs while centering the community. We applaud the leadership of Mayor Spencer's administration and President Green, Ald. Schweitzer, Ald. Sonnier, and Ald. Oldenburg for their collaboration to get this bill across the finish line."

John Stiffler (Executive Secretary-Treasurer, St. Louis Building & Construction Trades Council)

"The City of St. Louis is leading our region, and possibly our nation, in providing a path for local governments and school districts to benefit from data center development while addressing resident concerns. Going down this road will create thousands of good paying, union jobs, for skilled tradesmen and tradeswomen."

Ron Kitchens (Managing Partner, Greater St. Louis, Inc.)

"We commend Mayor Spencer and the BoA for their work passing this legislation, which gives St. Louis the opportunity to secure new, transformational economic opportunities that will generate hundreds of millions of dollars in new investment for our city. St. Louis is already set to see $3 billion in investment through the Midtown data center project, and our team at Greater St. Louis, Inc. is excited by the prospect of billions more on the horizon."