Installing or repairing a drywell for pay takes an Arizona contractor class that lists dry wells, such as A-12 or A-4 Drilling. An engineer designs it, and in Phoenix a city inspector approves the bore before backfill. The owner registers it with ADEQ and must keep it cleaned; Phoenix sets at least every three years.
Which contractor license covers drywell installation
Arizona's commercial license rule, R4-9-102, mentions dry wells in two classes. Under R4-9-102, the A-12 scope "Includes connecting sewer collector lines to building drains and the installation of septic tanks, leach lines, dry wells, all necessary connections, liners and related excavating and backfilling." The same rule, R4-9-102, gives A-4 Drilling the drilling of wells and "constructing dry wells, and monitor wells."
So a new drywell can involve a drilling contractor for the bore and an A-12 contractor for the inlet, pipe and connections. One firm with both classes, or with the A General Engineering class (which includes the A-4 through A-19 scopes), can do the whole thing. What each class covers in detail is on our page about what an A-12 license covers.
Can an owner do it without a license?
Rarely, for a drywell. A.R.S. 32-1121(A)(5) exempts owners doing their own work only when the property is "intended for occupancy solely by the owner" and "not intended for occupancy by members of the public as the owner's employees or business visitors," and isn't for sale or rent. Most drywells drain commercial lots, HOA common areas and subdivisions. Those sites have business visitors, tenants or buyers, so the owner exemption doesn't fit and the work needs a licensed contractor.
Who designs it and signs off
An engineer designs it, and the city inspects it. In Phoenix, the Stormwater Policies and Standards Manual says "Dry wells shall be designed in conformance with ADEQ guidelines." Drywells have to go at least ten feet into permeable porous strata, or percolation tests are required after construction. And "The City inspector must inspect and approve the well before backfill or well pipes are placed within any dry well bore holes."
Phoenix's grading and drainage checklist adds the plan side. Drywell detail and specifications go on the grading and drainage plans, and the checklist refers to a Professional Engineer of Record for those plans. Its required plan notes also put registration and any underground injection well permitting on the owner or developer. Other Valley cities and the county have their own drainage standards, so ask the city where the site sits. For what a drywell is built from, see what a drywell is and how commercial sites use one.
Who registers it with ADEQ
The owner or operator does. A drywell is a Class V injection well. Rule R18-9-I652 says "The owner or operator of an injection well authorized by rule under R18-9-I650 shall submit inventory information to the Director." Under R18-9-I650, transferring ownership of a well takes an inventory and a transfer fee, and an owner who fails to submit inventory information on time is prohibited from injecting into the well. The full process is on whether drywells still need to be registered.
Who cleans it, and how often
The owner is responsible, and Phoenix puts a clock on it. The manual says "it shall be the owner's responsibility to clean and maintain each structure to assure that each remains in proper working order. Under no condition shall the regular maintenance schedule be greater than every three years." It also says dry wells that stop draining a facility within the 36 hour period "shall be replaced/refurbished by the owner with new ones."
None of the rules we read ties routine sediment cleaning to a specific license class. Repair is different. The A-12 and A-4 scopes cover installing, constructing and repairing, so a refurbish or replacement goes back to a licensed contractor. Whether a drywell can be cleaned or has to be replaced is covered in can a plugged drywell be cleaned or replaced.
Who closes an old one
The owner or operator, under rule. R18-9-I650 says "Prior to abandoning a Class V well, the owner or operator shall meet the plugging requirements in R18-9-B614 (C)." That section requires closing the well in a way that keeps fluid with a contaminant from moving into an underground source of drinking water, where that contaminant could violate a primary drinking water regulation or otherwise harm people's health. It also says the owner must handle "any soil, gravel, sludge, liquids, or other materials removed from or adjacent to the well" under all applicable federal, state and local rules.
| Task | Who | Rule or source |
|---|---|---|
| Bore the well | A-4 Drilling (or A General Engineering) | R4-9-102 |
| Install pipe, connections, chamber | A-12 (or A General Engineering) | R4-9-102 |
| Design and plans | Engineer, per ADEQ guidelines | Phoenix manual 6.8.13, TRT 00047 |
| Inspect bore before backfill | City inspector (Phoenix) | Phoenix manual 6.8.13 |
| Register in the Class V inventory | Owner or operator | R18-9-I652 |
| Clean and maintain, at least every 3 years | Owner (Phoenix) | Phoenix manual 6.8.13 |
| Close and plug | Owner or operator | R18-9-I650, R18-9-B614(C) |
What to do if your drywell is due
- 1Pull the site's grading and drainage plan. It shows how many drywells you have and where.
- 2Check the last cleaning date. In Phoenix, three years is the limit.
- 3Confirm the inventory in myDEQ, especially after a sale.
- 4Hire for the job you have. Cleaning, refurbishing and replacing aren't the same job, and a replacement needs a licensed contractor and an engineer.
HQ holds an Arizona A-12 license. On a drywell we clean the sludge off the leach rock so water can soak in again. On a catch basin we jet the line all the way to the retention area. Pumping the standing water out isn't a fix, because the cause is still there. See commercial drywell cleaning for the service.