Identify the water’s source, quality and proposed destination before discharging trench-dewatering or hydrostatic-test water. Arizona’s De Minimis General Permit covers certain eligible discharges to protected surface waters under conditions; sanitary-sewer disposal requires the receiving utility’s authorization and applicable limits. A street, storm drain, drywell or cleanout is not automatic permission to discharge unknown water.
What does the Arizona de minimis permit cover?
ADEQ's De Minimis General Permit includes eligible potable-water-system discharges, hydrostatic testing and specified subterranean dewatering, among other categories. Coverage is subject to water-quality, best-management-practice and other permit conditions. The current permit became effective September 1, 2026; its requirements should be checked against the particular discharge rather than relying on an older authorization.
The program addresses eligible discharges to protected surface waters. Being listed as a type of potentially eligible activity does not authorize any volume, duration, contamination level or receiving location. Ask ADEQ which coverage or exception applies, what information and monitoring are required and whether an NOI through myDEQ is needed before discharge.
Is the sanitary sewer another option?
A sanitary-sewer destination requires a separate receiving-utility decision. Federal pretreatment rules prohibit discharges that cause pass-through or interference and include specific prohibited-discharge conditions. A cleanout provides physical access; it does not grant permission to dispose of groundwater, chemicals or trucked waste there.
Give the utility the source, estimated amount and flow, known additives, available water-quality information and proposed connection. Obtain its instructions before relying on sewer disposal. Vacuum-truck waste disposal has its own designated-receiving requirements.
What should the work plan document?
Identify the responsible party, applicable authorization, receiving point and restrictions. Ask the qualified team to assess sampling, treatment such as required dechlorination, erosion protection and any necessary containment or offsite disposal. Do not prescribe a treatment from appearance or odor alone, and do not improvise discharge of potentially contaminated water into a street or drywell.
Retain the approval, required readings or laboratory records, discharge dates and disposal documentation. Keep unexpected contamination or changed conditions connected to the approval process. The construction-stormwater assessment answers a related project-coverage question; it does not itself approve every pumped liquid produced during the repair.
The water source is a separate planning question. For a project proposing utility hydrant water, see temporary construction-water authorization alongside the discharge plan.