How do I know if I have septic or city sewer in Phoenix?

Your bill is the single clearest clue. If you see a separate monthly sewer or wastewater charge, you are connected to city sewer. That line item is how the City of Phoenix Water Services Department bills you for treating the wastewater that leaves your house. Many Phoenix accounts combine water and sewer on one statement, so look for a sewer subtotal even if the total is one number.

If the sewer or wastewater charge reads $0.00, or there is no sewer line on the bill at all, you very likely have septic. A septic system treats wastewater on your own property. The city has nothing to bill you for, so the charge is zero. Some rural properties get no water bill either, because they pull from a private well.

One caution: a missing charge alone is not proof. Billing errors happen. Some areas are also served by a separate sanitary district rather than the City of Phoenix. Use the bill as your starting point. Then confirm with the yard check and public records below before you act on it.

If you cannot find a paper bill, log in to your online utility account or call the billing office and ask one question: is there a sewer or wastewater charge on this address? The answer takes about a minute and points you in the right direction.

Wastewater systems leave physical signs above ground, and they are easy to spot once you know what you are looking at.

For a septic system, look for these features:

• A septic access riser or lid, often a black or green plastic disc roughly 10 feet from the house, sometimes flush with the soil or rising a few inches above it.
• An older system may have a square or round concrete lid instead of a plastic riser.
• A drainfield (also called a leach field), which can show up as a flat or slightly mounded area of yard with evenly spaced lines, often where the grass grows differently than the rest of the lawn.

For city sewer, the giveaway is a sewer cleanout: a capped pipe, usually white PVC, sticking a few inches out of the ground between the house and the street or near the property line. That cleanout marks the lateral line running to the public sewer main under the road. A home on septic has no such pipe heading toward the street.

The EPA describes the basic difference plainly. A septic system is a buried, on-site treatment setup. As the agency puts it, "Septic systems are underground wastewater treatment structures, commonly used in rural areas without centralized sewer systems." City sewer works the other way. It carries waste through public pipes to a regional treatment plant that the city runs.

If you find a riser lid but cannot tell whether it is live, do not pry it open or dig around it. The contents are under pressure and can hold sewer gas. A quick look from the surface is enough for now, and a plumber can open it safely if you need a closer check.

Where your home sits is a strong hint. Properties inside the City of Phoenix and other incorporated cities are usually on municipal sewer, because the city extends sewer mains as it develops an area. Homes in rural or unincorporated parts of Maricopa County are far more likely to be on septic, since running sewer lines to scattered lots is costly and often impractical.

A private well is another tell. Wells and septic systems usually go together, because a property without city water service typically has no city sewer service either. If you draw your own water from a well, you almost certainly treat your own wastewater with septic.

Your neighbors can confirm the pattern. Sewer and septic service tend to be uniform within a subdivision or street, so if the houses around you are on septic, yours probably is too. Ask a long-time neighbor, or look for the same yard riser lids on nearby lots. These clues stack up: a rural address plus a well plus visible riser lids is a clear septic picture, while a city address with a curbside cleanout and a monthly sewer charge points to sewer.

The clues above usually agree, but for a definite answer, go to the source. Septic systems in Arizona are permitted and tracked, so a public record almost always exists.

• Maricopa County Environmental Services keeps onsite wastewater (septic) permit and inspection records. The county runs the transfer-of-ownership inspection program, so if a property has a septic system, the county likely has a file on it.
• Arizona DEQ (ADEQ) oversees onsite wastewater treatment facilities statewide and maintains the Notice of Transfer records for septic properties.
• The City of Phoenix Water Services Department can confirm whether your address has an active sewer account and connection.

A quick call to the local permitting office settles it. Ask whether your parcel has an onsite wastewater (septic) permit on file or an active city sewer connection. Have your address and parcel number ready so the staff can pull the right file.

Title paperwork from when you bought the home is another good record. In Arizona, a septic system must be inspected before a property transfer. If your home has septic, your closing documents probably include a Report of Inspection. That report names the system type, its condition, and the date the tank was last pumped. A real estate disclosure form from the sale may also state the wastewater type outright.

The answer is not trivia. It changes your responsibilities and your costs.

If you are on septic, the whole system is yours to maintain. The EPA recommends having a typical system inspected at least every three years. Most tanks need pumping every three to five years. The exact gap depends on household size and tank capacity. Skipping this is how a tank fills with solids and a drainfield fails.

You also have to watch what goes down the drain. The EPA's guidance is blunt: "your septic system is not a trash can." Wipes, grease, and harsh chemicals can clog the drainfield. They can also kill the bacteria that make the system work. A failing septic system is far more expensive to fix than routine pumping, so the upkeep pays for itself. (See our guide on how often to pump a septic tank.)

If you are on city sewer, you pay a monthly fee and the city treats the wastewater, but you still own and maintain the lateral line running from your house toward the main. In Phoenix, the homeowner is generally responsible for that connection, with a limited exception for breaks in the public right-of-way for single-family and duplex properties. (See who is responsible for the sewer line in Phoenix and septic vs. sewer: what is the difference.)

Once you confirm which system you have, write it down with the location of your cleanout or septic lids. That single note saves time and money the day a drain backs up, because the plumber knows exactly where to start. If you are still unsure after checking your bill, your yard, and county records, HQ Plumbing & Air can identify your setup, locate the lines, and inspect the system. Call us at (602) 675-1555.