A data center with cooling towers can pay for its water twice: once to buy it, and again in sewer charges. How large the second bill is depends on how the local utility measures sewer use, and the utilities below measure it in different ways.
This page collects published rates and sewer billing rules in major data center markets. Every figure links to the utility’s own schedule. Rates change every year, so check the current schedule before using any of them in a budget.
How utilities measure sewer use
- On the water meter. The sewer charge follows the water meter, so every gallon bought is billed again as sewer, including water that evaporates. Fairfax County bills commercial sewer “based on their actual water consumption” (Fairfax County), and Chandler, Arizona bills its non-residential sewer volume charge “on each thousand gallons of metered water use” (City of Chandler).
- On the water meter, minus separately metered water that never reaches the sewer. Loudoun Water assumes sewage equals the water metered to the premises, “less those branches carrying flows separately metered by Loudoun Water, and serving only appliances and/or facilities that are not connected to the public sewer in any manner”, and its Rule 10(b) covers appliances or processes that discharge significantly less than they draw (Loudoun Water rates, rules and regulations, Rule 10).
- On water delivered. Mesa, Arizona bills general commercial wastewater per 1,000 gallons of water delivered (Mesa utility rate book).
- On what is actually discharged. The same Mesa rate book bills industrial wastewater customers by “quantity and strength of wastewater discharged”.
The method decides what reducing blowdown is worth. Under methods 1 and 3, every gallon of makeup water avoided also lowers the sewer bill. Under method 4, and for a site that already meters its tower separately under method 2, evaporated water carries little or no sewer charge, so the sewer saving is smaller. Four of the eight schedules below do not state the method, so ask your utility.
Published rates in data center markets
Volumetric charges per 1,000 gallons at the first commercial tier, excluding fixed and meter charges. Larger customers may fall in a different class or tier.
| Utility | Water | Sewer | Sewer measured on | Effective | Source |
|---|---|---|---|---|---|
| Loudoun Water, VA | $4.42 | $6.59 | Water meter, minus separately metered non-sewer branches | Jan 2026 | Loudoun Water |
| Fairfax Water and Fairfax County, VA | $4.35 | $9.88 | Actual water consumption | Apr 2026 (water); sewer from Oct 2026 meter readings | Fairfax Water, Fairfax County |
| Charlotte Water, NC | $4.88 | $9.20 | Not stated on the rate page | Jul 2026 | Charlotte Water (published per 100 cubic feet, converted) |
| Houston Public Works, TX | $9.34 | $11.80 | Not stated on the rate sheet | Apr 2026 | Houston Public Works |
| Austin Water, TX | $5.57 | $11.62 | Not stated on the rate sheet | 2026 | Austin Water |
| Metro Water Services, Nashville, TN | $4.42 | $9.38 | Not stated on the rate page | 2026 | Metro Water Services (published per 100 cubic feet, converted) |
| Chandler, AZ | $2.73 | $5.03 | Metered water use | Mar 2026 | City of Chandler |
| Mesa, AZ (general commercial) | $5.39 above 3,000 gal, plus surcharges in the rate book | $4.16 above 5,000 gal | Water delivered | Jan 2026 | Mesa rate book |
On these schedules, water plus sewer runs from $7.76 per 1,000 gallons in Chandler to $21.14 in Houston, and sewer is the larger of the two charges in seven of the eight markets listed.
State rules are starting to apply
Water and sewer rates are set locally, but Florida now sets a state condition for large data centers. Florida’s 2026 law requires the water management district or state to require reclaimed water for a large-scale data center’s allocation when certain requirements are met (Florida SB 484).
How to check your own site
- Find your utility’s current rate schedule and the section that defines how sewer volume is measured.
- Check whether the site already has a cooling tower submeter, deduct meter or evaporation credit.
- Price blowdown at the rate that actually applies: water plus sewer under methods 1 and 3, mostly water alone under method 4 or with a separately metered tower.
Where Nona fits
Nona RECOVER treats cooling tower blowdown on site and returns it to the tower, which lowers makeup water purchases and, where sewer is billed on metered or delivered water, sewer charges too. The savings calculator uses published utility rates like these for a specific site, and our guide to choosing a recovery system covers what to ask any vendor.
Sources
- Loudoun Water, Rates, Rules and Regulations, Rule 10, rates effective January 2026
- Fairfax Water, Rate Schedule, effective April 2026
- Fairfax County Department of Public Works, Sewer charges FAQs, rates for service from July 1, 2026, billed to metered accounts from readings beginning October 2026
- Charlotte Water, Rates and fees, commercial, per 100 cubic feet ($3.65 water, $6.88 sewer), effective July 2026
- Houston Public Works, Water and wastewater rates, effective April 2026
- Austin Water, Commercial and public rates 2026
- Metro Water Services, Rates, non-residential, per 100 cubic feet ($3.31 water, $7.02 sewer)
- City of Chandler, Utility rates, effective March 2026
- City of Mesa, Utility rate book, effective January 2026
- Florida Senate, SB 484 (2026), enrolled bill text