Setback Requirements
18 A.A.C. 9 Arizona Administrative Code Title 18, Ch. 9
Department of Environmental Quality – Water Pollution Control
C. Setbacks
The following setbacks apply unless the Department:
- Specifies alternative setbacks under Article 3, Part E of this Chapter;
- Approves a different setback under the procedure specified in subsection (G);
- Establishes a more stringent setback on a site or area specific basis to ensure compliance with water quality standards.
| Features Requiring Setbacks | Setback For An On-Site Wastewater Treatment Facility, Including Reserve Area (In Feet) | Special Provisions |
|---|---|---|
| 1. Building | 10 | Includes porches, decks, and steps (covered or uncovered), breezeways, roofed patios, carports, covered walks, and similar structures and appurtenances. |
| 2. Property line shared with any adjoining lot or parcel not served by a common drinking water system* or an existing water well | 50 |
A person may reduce the setback to a minimum of 5 feet from the property line if: a. The owners of any affected undeveloped adjacent properties agree, as evidenced by an appropriately recorded document, to limit the location of any new well on their property to at least 100 feet from the proposed treatment works and primary and reserve disposal works; and b. The arrangements and documentation are approved by the Department. |
| 3. All other property lines | 5 | None |
| 4. Public or private water supply well | 100 | None |
| 5. Perennial or intermittent stream | 100 | Measured horizontally from the high water line of the peak streamflow from a 10-year, 24-hour rainfall event. |
| 6. Lake, reservoir, or canal | 100 | Measured horizontally from the high water line from a 10-year, 24-hour rainfall event at the lake or reservoir. |
| 7. Drinking water intake from a surface water source (includes an open water body, downslope spring or a well tapping streamside saturated alluvium) | 200 | Measured horizontally from the on-site wastewater treatment facility to the structure or mechanism for withdrawing raw water such as a pipe inlet, grate, pump, intake or diversion box, spring box, well, or similar structure. |
| 8. Wash or drainage easement with a drainage area of more than 20 acres | 50 | Measured horizontally from the nearest edge of the defined natural channel bank or drainage easement boundary. A person may reduce the setback to 25 feet if natural or constructed erosion protection is approved by the appropriate flood plain administrator. |
| 9. Water main or branch water line | 10 | None |
| 10. Domestic service water line | 5 |
Measured horizontally between the water line and the wastewater pipe, except that the following are allowed: a. A water line may cross above a wastewater pipe if the crossing angle is between 45 and 90 degrees and the vertical separation distance is 1 foot or more. b. A water line may parallel a wastewater pipe with a horizontal separation distance of 1 foot to 5 feet if the bottom of the water line is 1 foot or more above the top of the wastewater pipe and is in a separate trench or on a bench in the same trench. |
|
11. Downslopes or cut banks greater than 15 percent, culverts, and ditches from: a. Treatment works components |
10 |
Measured horizontally from the bottom of the treatment works component to the closest point of daylighting on the surface. |
|
b. Trench, bed, chamber technology, or gravel less trench with: i. No limiting subsurface condition specified in R18-9-A310(D)(2) |
20 | Measured horizontally from the bottom of the lowest point of the disposal pipe or drip lines, as applicable, to the closest point of daylighting on the surface. |
| ii. A limiting subsurface condition. | 50 | |
| c. Subsurface drip lines. | 3 | Measured horizontally from the bottom of the lowest point of the disposal pipe or drip lines, as applicable, to the closest point of daylighting on the surface. |
| 12. Driveway | 5 | Measured horizontally to the nearest edge of an onsite wastewater treatment facility excavation. A person may place a properly reinforced and protected wastewater treatment facility, except for disposal works, at any location relative to a driveway if access openings, risers, and covers carry the design load and are protected from inflow. |
| 13. Swimming pool excavation | 5 | Except if soil loading or stability concerns indicate the need for a greater separation distance. |
| 14. Easement (except drainage easement) | 5 | None |
| 15. Earth fissures | 100 | None |
* A “common drinking water system” means a system that currently serves or is under legal obligation to serve the property and may include a drinking water utility, a well-sharing agreement, or other viable water supply agreement.