Data centers are limited by type and zoning district: medium centers are allowed with conditions in C-2, I-1, I-2, I-3, and specified MXD commercial-use groups; micro centers in C-2, HID, I-1, I-2, I-3, and specified MXD groups; and hyperscale centers in I-1, I-2, I-3, and MXD commercial-use group 3. The measure also requires Board special-exception approval for hyperscale centers in I-1 and MXD commercial-use group 3. Hyperscale Data Center

Accessory data centers are limited to 10% of the lot's gross floor area, must serve only the on-site tenant or property owner, cannot be leased to third parties, and cannot occupy a separate stand-alone structure. no more than ten percent

Medium data centers must be at least 250 feet from residential or urban neighborhood districts, measured from buildings and ancillary equipment to the nearest district property line. two hundred fifty (250) feet

Hyperscale centers in I-1, I-3, and MXD commercial-use group 3 must maintain a 500-foot separation from residential or urban neighborhood districts; in I-2, they must meet the setbacks of any residential or urban neighborhood district they abut. Hyperscale centers are also barred within 1,000 feet of a City-designated high-capacity transit facility. five hundred (500) feet

A hyperscale center must be on a lot of at least five acres. Non-contiguous parcels cannot be aggregated to meet the minimum, and the lot cannot be subdivided below five acres while the center remains in operation. minimum of five (5) acres

Applicants for medium and hyperscale centers must demonstrate adequate water and wastewater capacity. Hyperscale applications must also report water use, cooling systems, sources, and efficiency measures, and submit a water-conservation plan. Public-water users need supply certification; applicants using nonpublic water must provide a feasibility study assessing supply and effects on nearby wells, groundwater, and surface waters. water conservation and efficiency plan

Hyperscale applicants must provide electrical-demand and phasing estimates, identify utility providers and required on- and off-site infrastructure, disclose new or expanded utility facilities and off-site work, and obtain written confirmation from the serving electric utility that capacity will be available. written confirmation from the serving electric utility

Hyperscale applicants must submit a site development plan showing buildings, ancillary infrastructure, setbacks, screening, access, and utility connections. site plan that includes

Medium and hyperscale centers may not create, maintain, or permit illicit connections or discharges to the municipal stormwater system; violations are declared a public nuisance subject to correction or abatement. No hyperscale data center shall create

Hyperscale applicants must provide generator type and fuel, capacity, testing and maintenance schedules, and noise-mitigation measures, and submit pre- and post-construction noise studies demonstrating compliance. pre-construction noise study

Hyperscale backup generators may be used only for outages, emergencies, testing, or maintenance; routine testing is limited to daytime hours. Generators must meet applicable emissions standards and be enclosed or acoustically screened, and backup systems cannot be used for routine grid support, economic dispatch, or other non-emergency generation. used only during power outages

Routine or primary on-site power generation is prohibited for hyperscale centers and medium centers, subject to the measure's stated solar and/or fuel-cell exceptions in the conditional-use provisions. Fossil-fuel systems are limited to emergency backup, testing, and maintenance; on-site battery storage charged by grid power or solar is allowed. The hyperscale special-exception provisions specify solar, rather than solar and/or fuel cells, as the exception. strictly prohibited

Hyperscale centers must use closed-loop cooling designed to recirculate water and minimize potable-water use. Potable water cannot be relied on for routine cooling, and cooling-water discharge must be pretreated for contaminants and cooled to applicable discharge standards. shall utilize closed loop cooling systems

Medium and hyperscale centers must screen roof- and ground-mounted mechanical equipment and ancillary infrastructure from public view. Hyperscale facilities with battery storage must submit an emergency-response coordination plan for Fire Department review. screened from public view

Hyperscale centers must meet specified outdoor-lighting limits, including limits on uplight, light trespass onto protected areas, waters, residential property, and public rights-of-way, and a maximum 3000 K color temperature. maximum allowable correlated color temperature

Owners or developers of new or expanded hyperscale centers must notify all property owners within 500 feet by certified mail and provide copies of the notices and delivery tracking numbers with the building-permit application. within a radius of five hundred

An increase in a center's floor area, electrical demand, water use, cooling capacity, backup-generation capacity, or fuel-storage capacity beyond the approved plan is a material change requiring review and approval; for hyperscale centers, such increases require a new compliance review. Phased projects must disclose ultimate build-out, and classification is based on that ultimate capacity. material change in use

Micro data-center backup generators are limited to emergencies, testing, and maintenance; routine testing must occur during daytime hours, and other on-site power generation is prohibited. A micro center abutting a residential or urban neighborhood district must use that district's required setbacks. solely for emergency use

Medium data centers are allowed with conditions in C-2, I-1, I-2, I-3, and MXD Commercial Use Groups 2 and 3. “a medium data center shall be permitted”

Micro data centers are allowed with conditions in C-2, HID, I-1, I-2, I-3, and MXD Commercial Use Groups 2 and 3. “a micro data center shall be permitted”

Hyperscale data centers are allowed with conditions in I-1, I-2, I-3, and MXD Commercial Use Group C-3. “a hyperscale data center shall be permitted”

A separate special-exception route allows hyperscale data centers in I-1 and MXD Commercial Use Group 3, subject to Board approval and the listed conditions. “Hyperscale Data Center”

Accessory data centers are allowed in MU-L, MU-M, MU-H, MU-D, C-1, C-2, HID, I-1, I-2, I-3, and MXD Commercial Use Groups 1, 2, and 3. Limits: they may occupy no more than 10% of gross floor area, must serve the on-site enterprise, cannot be leased to third parties, and cannot be in a separate standalone structure. “no more than ten percent (10%)”

The conditions for medium and hyperscale data centers allow on-site solar and/or fuel cells as a primary, parallel, or routine power source. Fossil-fuel generation is limited to emergency backup, testing, and maintenance; grid-charged or solar-charged batteries may supplement power during outages or peak-demand hours. “except solar and/or fuel cells”