Aldermen amend St. Louis data‑center zoning; bill sent back to planning for review

The St. Louis Board of Aldermen spent much of its session on a proposed ordinance to create a dedicated data‑center chapter in the zoning code, discussing where data centers could go, what information applicants must provide, limits intended to protect nearby residents and institutions, and how to enforce renewable‑energy and noise controls.

The sponsor, identified in the record as the alderwoman from the 1st, told the board the bill establishes size tiers (micro, standard, major) and application standards — including detailed site plans, maximum power‑demand declarations and attestations from electric service providers — ‘‘because people in our community are concerned about this use and how it will affect them,’’ and to ensure the city has information up front when deciding whether an applicant will be ‘‘a good actor, a good partner’’ under a conditional use permit.

Why it matters: supporters and opponents framed the discussion as a balance between climate and local quality‑of‑life protections on one hand, and economic activity and downtown activation on the other. Supporters pointed to rules on generator testing, noise and setbacks and to phased renewable‑energy requirements meant to limit emissions. Opponents warned amendments could weaken those protections or allow concentrations of high‑density data centers in downtown blocks.

Key floor changes - Amendment 4 (ground‑floor activation/percent cap): adopted after extended debate. The amendment creates a process by which a data‑center applicant may seek to exceed a standard 30% cap on data‑center floor area in certain high‑intensity districts if the owner commits to a higher net leasable ground‑floor activation threshold and negotiates community benefits with the city. Supporters said the tool would let the city negotiate active uses for vacant space; opponents said it risks inconsistent treatment and could encourage clustering of data centers. The roll call for amendment 4 was recorded as 10 ayes and 4 noes.

- Amendment 5 (renewable‑energy waiver process): adopted by roll call (12 ayes, 3 noes). The amendment creates a defined waiver process administered by the Board of Public Service when an electric utility is ‘‘verifiably unable’’ to provide the bundled renewable energy required under the ordinance. The sponsor of the amendment described it as a market‑contingent off‑ramp backed by documentary requirements from utilities; critics said it could undercut the ordinance’s climate protections and warned against a permanent or permissive retreat from the bill’s phased renewable standards.

- Amendment 6 (institutional campus clarification): adopted by roll call (9 ayes, 5 noes). The amendment narrows an exception for data centers that exclusively serve institutional campuses (for example, certain medical or research campuses) to allow micro or standard facilities to be sited on campus under strict conditions intended to preserve protections for parcels outside the campus.

Votes and next steps: after adopting multiple amendments on the floor, the sponsor withdrew perfection and moved to place board bill 49 on the informal calendar so that it can return to the planning commission for additional review; the motion was granted and the clerk noted the bill must be considered by planning before final passage.

What supporters said: the alderwoman from the 1st repeatedly emphasized stakeholder engagement and the need for detailed upfront application requirements, saying the bill protects residents while providing a path for the use. The alderman from the 2nd, defending the renewable waiver amendment, said the bill still requires ‘‘100% renewable energy for 10 years’’ as a standard and described the waiver as a narrowly defined, evidence‑based process when utilities truly cannot supply required renewables.

What opponents said: several members voiced concern that some floor amendments weaken consistent standards (notably the 30% cap) or create discretionary exceptions that could be exploited, and urged clearer enforcement language and definitions before final passage.

Where this goes next: the ordinance as amended on the floor will return to the planning commission for review because the floor amendments were considered substantive. The board left the item on the informal calendar pending that review.

Ending: The Board did not take a final vote on board bill 49; instead it referred the revised bill back to the planning commission for further consideration.