Calvert planning commissioners ask for public and staff comments on draft data center rules after residents raise water, noise and environmental concerns

Planning commissioners on March 18 reviewed draft text amendment 26‑23, which would add conditions for data centers in the Calvert County Zoning Ordinance, and directed staff to collect written feedback from commissioners and the public by April 2.

Deputy Director of Zoning Rachel O'Shea outlined the draft conditions, including a 400‑foot separation from any lot or parcel with a residential building or an active residential building permit, facade treatments to avoid an unbroken plane, strict compliance with chapter 80 (the county Noise Control Ordinance), and a requirement that no groundwater well be drilled or used for cooling or humidification. The draft would require a water services plan prepared by a Maryland‑licensed professional engineer estimating average and peak cooling water demand, identifying nonpotable sources where practical, and requiring updates before any material expansion that increases projected average daily cooling water demand by more than 10 percent.

"Prior to any applicable Planning Commission meeting, the applicant shall conduct at least one public meeting in the election district in which the use is proposed," O'Shea said, summarizing the citizen‑engagement step slated in the amendment.

Jason Brinkley, the county's Director of Planning and Zoning, told commissioners no project had been formally submitted to Calvert County as of the meeting date and clarified the applicant‑hosted AWS open house would not substitute for the county's required informational meeting. "Nothing has been submitted to Calvert County for review," Brinkley said, noting that state‑level filings (for wetlands or steep‑slope reviews) may precede a county application but do not replace county procedures.

Commissioners pressed staff on technical points. One commissioner asked whether a change in the county stormwater standard — including a revised definition of a "100‑year" storm to account for climate change — would be applied prospectively or to projects already in the pipeline; staff said that was under discussion. Commissioners also asked how wastewater upgrades would be treated if a data center proposed to use treated effluent for cooling; staff said any wastewater improvements required to serve a data center would be the applicant's responsibility under the county Adequate Public Facilities Ordinance, and APFO sewer‑performance thresholds would still apply.

Concerns from commissioners and members of the public centered on low‑frequency noise propagation and long‑term environmental impacts. A commissioner urged staff to review best practices and scientific literature on whether the county's 75‑decibel standard adequately captures low‑frequency, continuous hums sometimes associated with large data centers. A member of the public identified an MDE application for a "Calvert County Data Center Project," citing "three campuses with a total of seven buildings, totaling 225,000 square feet and 500 megawatts of data capacity," and called for stronger, enforceable protections for water, air and noise.

Public commenters called for requirements the county said staff would consider, including preferential liquid cooling, limits on light pollution, decommissioning bonds, on‑site air and water monitoring, and strict enforcement (including stop‑work orders for violations).

After discussion about process and timing, Commissioner (speaker 3) moved that the Planning Commission review the proposed text amendment, submit written comments to staff by April 2, and direct staff to compile those comments (including the evening's discussion) for presentation at the April meeting. The motion was seconded, taken by voice vote and carried.

Next steps: staff requested commissioners and members of the public email comments by April 2; staff will compile comments into a memorandum and return with a summary at the Planning Commission's April meeting before forwarding recommendations to the Board of County Commissioners.