Septic permit rules and requirements in Delaware

Who issues a septic permit in Delaware

The state issues the permit itself, through the Groundwater Discharges Section, Division of Water, Delaware Department of Natural Resources and Environmental Control (DNREC).

The Department issues every septic permit. A county must approve zoning first, but it does not issue the permit.

7 DE Admin. Code § 7101, § 3.10 · checked 2026-09-11

The office publishes its own page on this: Delaware Department of Natural Resources and Environmental Control — Division of Water, Groundwater Discharges Section.

The page names this address as its own link.

Delaware Department of Natural Resources and Environmental Control — Division of Water, Groundwater Discharges Section · checked 2026-09-23

Where the rule is written

The rules that govern every septic system in Delaware are 7 DE Admin. Code 7101 — Regulations Governing the Design, Installation and Operation of On-Site Wastewater Treatment and Disposal Systems. The state applies them directly.

This section sets the rule's purpose and scope. It covers septic design, installation and use across the state.

Delaware Administrative Code, Title 7, § 7101 · checked 2026-09-23

What state law requires

Does Delaware require a septic permit?

The state requires a permit to build, repair or change a septic system.

This rule is in § 3.31.1. It allows a narrow exception for an emergency repair.

Delaware Administrative Code, Title 7, § 7101 · checked 2026-09-23

Does Delaware require a percolation test?

The state requires a site evaluation from a licensed soil scientist before it issues a permit.

This rule is in § 5.2.1.1. The scientist may run a percolation test or assign a rate for the soil.

Delaware Administrative Code, Title 7, § 7101 · checked 2026-09-23

The minimum septic tank size Delaware allows.

1,000 gallons.

Applies to a dwelling with four bedrooms or fewer.

This rule is in § 5.3.14.4. The tank must have two compartments. The larger one holds most of the liquid.

Delaware Administrative Code, Title 7, § 7101 · checked 2026-09-23

How far the tank must sit from a well in Delaware.

50 feet.

Applies to a septic tank, a distribution box or a dosing chamber, to a private well.

This rule is in Exhibit C. The drainfield needs more room from a well, and a county may set a wider setback than the state floor.

Delaware Administrative Code, Title 7, § 7101, Exhibit C · checked 2026-09-23

How far a system must sit from the property line in Delaware.

10 feet.

Applies to a septic tank or the drainfield, to the property line.

This rule is in Exhibit C. A county may set a wider setback than the state floor.

Delaware Administrative Code, Title 7, § 7101, Exhibit C · checked 2026-09-23

Does Delaware require an inspection when a home is sold?

The state requires a pump-out and an inspection before a septic system changes owners.

This rule is in § 3.31.13. A sheriff sale, an auction or a cash sale gets more time to finish the work.

Delaware Administrative Code, Title 7, § 7101 · checked 2026-09-23

Must the installer be licensed in Delaware?

DNREC issues the permit to design, install, inspect or pump a septic system.

This program is in § 4.1. A separate permit covers each task.

Delaware Administrative Code, Title 7, § 7101 · checked 2026-09-23

Whether Delaware counts what it permits

Yes. Delaware publishes septic permit counts by county.

The office posts a live file of every septic permit. Each row names a county, so a reader can add up permits by county.

Delaware Department of Natural Resources and Environmental Control, Division of Water — Permitted Septic Systems · checked 2026-09-11

Delaware counties on this site

We have not published a Delaware county page yet. A county earns a page when we hold facts unique to it. Until then this page is the answer for every county in the state.

Telling us your county is how we decide which one to build next.

Get local answers

Sources

State records only. Each figure above has a government source and a checked-on date. County figures live on the county pages.

1. Delaware Department of Natural Resources and Environmental Control — Division of Water, Groundwater Discharges Section · checked 2026-09-23
2. 7 DE Admin. Code § 7101, § 3.10 · checked 2026-09-23
3. Delaware Department of Natural Resources and Environmental Control, Division of Water — Permitted Septic Systems · checked 2026-09-11
4. Delaware Administrative Code, Title 7, § 7101, Exhibit C · checked 2026-09-23