Water and Sewer Main Extensions: Who Pays and Who Builds, by City

Phoenix's Chapter 28, Article III is blunt: "The developer must pay for all the costs to design, permit, and construct the sewer main extension, including any costs of acquiring rights-of-way and easements." The same section adds the as-built plans and the city's own inspection to the developer's bill. The Director decides the layout and pipe size for peak flow, and if gravity won't work, the developer builds the lift station too.

Once the city accepts the work, the main is public. You paid for it, but you don't own it, and the article says no owner keeps "a legal or equitable right or interest" in it.

Common requirements in these extension provisions include:

• You pay: design, permits, right of way or easements, construction, inspection, and the street repair afterward.
• You build to their standard: city details and specifications, with the pipe size set by the city.
• You hand it over: title transfers on acceptance.
• Some cities pay back: Phoenix, Chandler, Glendale, Scottsdale and Surprise have agreements to recover part of the cost from later connectors. Phoenix's sewer repayment program wants at least three sealed bids before the city accepts the project and pays no interest.

• Main extension. New public water or sewer main laid to reach a property the system doesn't serve yet. Different from a service line or lateral, which runs from the main to one building.
• Frontage rule. Mesa and Scottsdale make you run the main along the entire street frontage of your parcel, not just to your tap, so the next lot can connect.
• Oversizing. When the city wants a bigger pipe than your project needs. Chandler and Scottsdale have code sections for the city sharing that extra cost.
• Payback, reimbursement or repayment agreement. A contract where the city collects a share from later users of your main and passes it to you.
• Approval to Construct. The state (ADEQ) sign-off to build or extend a public water system, under A.A.C. R18-5-505.

Anyone extending a public water or sewer main: developers, commercial owners building on an unserved pad, and owners converting from septic or a private well where the main is down the road. It also covers the engineers who design the line.

It does not apply to a single building's own service line or lateral from an existing main. ADEQ's sewage collection general permit specifically excludes "a gravity sewer line conveying sewage from a single building drain directly to" a sewer.

A medical office on a Gilbert half-section line. The water main has to be at least 8 inches, but the town can require bigger "if deemed advisable by good engineering practices." The developer also pays for the curb and sidewalk repairs the trench causes.

A Scottsdale owner who wants to be their own contractor. For a payback agreement on a line serving single-family property, Scottsdale requires three independent bids and says the developer or owner "cannot act as the Contractor." Skip the agreement and that restriction doesn't bite, but neither does the payback.

A Glendale developer whose neighbor connects first. The city collects the neighbor's allocated share before issuing their connection permit, then reimburses the developer from a trust account. The developer's own share of the pipe is never paid back.

The same project outside Glendale's limits. No agreement is possible: the code bars reimbursement agreements for extensions outside the city.

Settle the extension before the building plans, since it drives both schedule and cost.

1. 1Ask the water and sewer utility where the nearest main is, what size it is, and whether it has capacity for your flows.
2. 2Hire an Arizona-registered civil engineer. Phoenix requires one for sewer extensions, and the state rule normally requires a sealed design for water, with limited small-project provisions in R18-5-505(B)(2)-(4).
3. 3Get the ADEQ approvals in line: an Approval to Construct for water, and a 4.01 general permit when R18-9-E301 covers the sewer system. Its triggers include a manhole, a shared force main/lift station, and the specified 3,000-gpd design-flow threshold, subject to the single-building gravity-line exclusion.
4. 4File the extension permit with the city, and in Glendale or Chandler the reimbursement request at the same time.
5. 5Bid the work the way the city requires. Chandler and Glendale call for public-works style competitive bidding when the city shares cost or reimburses.
6. 6Build, pass inspection, and convey the main free of encumbrances, then pull the tap and connection permits.

• "The city extends mains when new customers ask." Not in these codes. Surprise reserves the right to build one, but the developer who causes it still pays in full.
• "We only need pipe to our tap." Mesa and Scottsdale require it along your entire frontage unless the city waives it.
• "Payback is automatic." Phoenix wants three sealed bids before acceptance, Chandler's window closes one year after acceptance, and Glendale needs the request filed with the extension permit.
• "A plumbing permit covers it." Main extensions are civil work with separate city permits and state approvals; the plumbing permit covers the building side.

ADEQ's rule says a person "shall not start to construct" an extension to a public water system before receiving an Approval to Construct. Mesa won't provide service through a main built by others until title is tendered and the city accepts it, and Gilbert's council must accept the extension before it can be used.

When the main is in and you need the building's taps, service lines and laterals built, HQ can help with building water and sewer lines. Public-main extensions require a separate civil design, utility approval and a contractor authorized for that work.