Two commercial parcels share one sewer line: who owns it and who repairs it?

Pull these first. They outrank everything else.

1. 1The deeds and plats for both parcels, which show whether a line crosses the boundary.
2. 2A recorded easement for the shared segment. It should say who may use the strip and may also say who maintains the pipe.
3. 3A maintenance or cost-sharing agreement, sometimes inside a reciprocal easement agreement or a declaration of covenants.
4. 4Lease terms, if tenants are responsible for repairs to shared lines.

An unrecorded paper may not protect you. Under A.R.S. 33-411, "No instrument affecting real property gives notice of its contents to subsequent purchasers or encumbrance holders for valuable consideration without notice, unless recorded as provided by law in the office of the county recorder." If you are buying or lending against a property, make sure the shared-line terms are recorded.

Generally no, where a city's code says so. Scottsdale defines a private sewer as "any wastewater collection system other than the POTW" and says "All private sewers shall be maintained by the property owner." Surprise says a private sewer is "a lateral, main or trunk sewer controlled and maintained by a private entity."

The city takes over at the public main. Our page on who repairs a sewer line in an easement behind your building explains how that line is drawn.

Arizona has a rule for shared easements. In Freeman v. Sorchych, the Arizona Court of Appeals considered two neighbors who used the same roadway easement and had no cost-sharing agreement. It concluded that "absent the creation of a duty expressly in the conveyance document or by other contract, the doctrine of equitable contribution should be extended to permit one dominant tenant to require another dominant tenant to contribute to the necessary repair and maintenance of an easement if both tenants are using the easement." The court said "the owners of the easement have the shared duty to repair and maintain the easement."

It quoted the Restatement (Third) of Property for the idea that holders who use the same improvements "have a duty to each other to contribute to the reasonable costs of repair and maintenance." And it noted that "The responsibility of each user should reflect a fair proportion of the costs."

Two cautions. The case involved a shared road, not a sewer, so a court deciding a sewer dispute would apply the principle to its own facts. And it applies when no agreement exists, because an agreement controls. If you have a dispute, an attorney who handles easements should advise you. This page cannot.

Phoenix does not like them. Its Planning & Development packet says "City Code and the building code requires that all building sites tie directly into city services without routing domestic sewer, water and fire lines across interior property lines or parcels." A developer is expected to extend public service to each lot. If that is not possible, "private utility easements, private maintenance agreements, and City of Phoenix approval" through a "Private Utility Crossing Property Line packet" "may be considered as an alternate solution."

Phoenix's amended building code says "No sewer service, water service, or electric wiring methods and equipment shall be built across a lot line, other than a lot line separating the lot being serviced from the adjacent public way." The building official may approve a service "located within a permanent, non-revocable private utility easement duly-recorded in the deed records of Maricopa County for all the properties involved."

That packet asks for specific paper. The applicant must give the plat or a recorded private utility easement and "a copy of a maintenance agreement identifying who or what entity is responsible for maintaining the proposed private sewer, water or fire service lines within the private utility easements for all parcels affected." Water Services approval is also required. If your Phoenix parcels share a line today, the city's own packet shows what the paper trail is supposed to look like.

1. 1Find out where the shared stretch starts and ends. A camera run shows the path, the joints and where each parcel connects.
2. 2Read the recorded documents. Look for the maintenance clause first.
3. 3Notify the other owner in writing with the camera findings and a repair scope.
4. 4Get a written price and propose a split that reflects each parcel's use. The court's comment about "a fair proportion" is the usual yardstick.
5. 5Put the agreement in writing and record it, so the next owner is bound too.
6. 6Check permits. If the work reaches an easement or the street, add the agency permits. See whether a plumber needs permission to work in a utility easement.

For a townhome version of the same cost-sharing question, see who pays when a shared line backs up in a townhome.

HQ Plumbing & Air inspects and repairs sewer lines with camera inspection, free estimates and upfront pricing, and can give both owners the same written findings.

This page explains general rules and is not legal advice. Your recorded documents and a licensed Arizona attorney's reading of them control.