United States & Canada

1) United States (US)
Cooling & water usage: the real regulatory levers

In the US, data centers are usually controlled through permits + local utility rules, not a single “data center water law.”

A. Water withdrawal / sourcing

Mostly state-level water rights / withdrawal rules (varies a lot by state and basin).

Your local water utility contract can impose hard caps, drought provisions, and connection constraints.

B. Discharge and blowdown

If you discharge wastewater (including cooling tower blowdown, RO concentrate, etc.) to surface waters, you’re in Clean Water Act / NPDES territory (limits + monitoring + reporting). EPA explains NPDES as the core discharge permitting framework for industrial/commercial sources.
Environmental Protection Agency

Thermal pollution (“heat”) can be regulated in permits; EPA has guidance on thermal discharges in NPDES permits.
Environmental Protection Agency

If you discharge to a sewer, you’re typically under local POTW pretreatment / industrial discharge rules (city/county utility).

C. Stormwater during construction/operations

Construction stormwater permits are common on large builds (again: CWA delegated to state agencies).

Who enforces (typical)

State environmental agency (often delegated EPA authority) for NPDES/stormwater.

Municipal water & sewer utility for supply + sewer discharge acceptance.

Power consumption: permitting is usually “indirect,” but strict

A. Grid / interconnection

Utility + often a state Public Utility Commission (PUC) drives interconnection studies, substation upgrades, curtailment programs, etc.

B. On-site generation (backup/prime power)

Emergency generator fleets often trigger Clean Air Act permitting (state/local air districts). EPA has a dedicated page on Clean Air Act resources for data centers, emphasizing permitting mechanics (e.g., “potential to emit” for generators).
Environmental Protection Agency

Local air districts may add their own engine permit requirements (especially in nonattainment areas).
BAAQMD

1) Canada

Canada is similar to the US in structure: most water + building energy rules are provincial/municipal, with federal involvement for certain major-project pathways and broader environmental obligations.

Cooling & water usage

A. Water withdrawal (“taking water”)

Often a provincial permit when withdrawals exceed a threshold. Example: Ontario’s Permit to Take Water applies when taking more than 50,000 litres/day from the environment.
Ontario

B. Discharge

Typically governed by provincial environment ministries and/or municipal sewer bylaws; requirements depend on whether discharge is to surface water vs. sewer.

C. Public health (cooling towers)

Some cities require operating permits and controls for cooling towers/water systems (Legionella risk management). Example: City of Vancouver’s operating permit program for cooling towers/water systems.
City of Vancouver

Power & energy efficiency

Provincial building codes / energy codes + utility connection requirements are the main drivers.

Canada’s federal energy-efficiency arm publishes operational best practices (not “hard law,” but often used in procurement and performance programs). Natural Resources Canada released a Best Practice Guide for Canadian Data Centres (2024) and promoted it again in 2025.
Natural Resources Canada

Federal “major project” pathway (situational)

The Impact Assessment Agency of Canada runs federal review processes for certain major projects (not “data-center-specific,” but relevant if your overall development triggers federal review).
Canada