State guide
Delaware
Delaware runs septic permitting as a statewide program within DNREC's Division of Water rather than through county health departments. DNREC's residential septic page describes a three-step process: site evaluation by a licensed Class D soil scientist, system design by a licensed designer, and installation by a licensed Class E contractor.
Checked against official sources on October 4, 2026. Rules and links change; confirm with the office listed before you act.
- Who regulates septic permits
- DNREC's Division of Water, through its Wastewater Disposal Program, oversees the siting, design, installation, permitting, and professional licensing for onsite wastewater systems statewide.
- Who can do the soil or perc test
- DNREC says site evaluations are performed by licensed Class D soil scientists, while Class A licensees are authorized to perform percolation tests.
- Official septic permit page
- Official page →
- Licensed evaluators or designers
- Official page →
- State fee
- $250 for Residential Wastewater Site Evaluation; $250 for Gravity Small System Construction, Upgrade/Replacement, Extension; and $250 for Engineered Small System New Construction, System Upgrade/Replacement.
Official resources in Delaware
Main state page for residential septic approvals, forms, permit lookup links, and the three-step approval process.
Official licensing page explaining Class A through Class I wastewater licenses and linking to current licensee lists.
Official search hub for permitted septic systems, permit status, inspection reports, and licensed onsite wastewater professionals.
Official statewide fee schedule showing septic site-evaluation and small-system permit fees.
Key facts for Delaware
- Delaware onsite wastewater systems are governed by 7 DE Admin. Code 7101.
- A new or replacement system applicant must first obtain a site evaluation report prepared by a Class D soil scientist.
- Class A licenses authorize percolation tests, and Class D licenses authorize site evaluations.
- DNREC says all onsite wastewater licensees are listed on the Delaware Open Data Portal and updated weekly.
- DNREC's fee page lists $250 for a residential site evaluation and $250 for gravity or engineered small-system construction permits.
- DNREC publishes separate wastewater-disposal contacts for New Castle and Kent Counties and for Sussex County.
County septic and soil-evaluation offices in Delaware
| County office | city | phone | Details |
|---|---|---|---|
| Wastewater Disposal — New Castle and Kent Counties New Castle County / Kent County | Not published* | Not published* | DNREC lists this contact for septic-system wastewater disposal work in New Castle and Kent Counties. |
| Wastewater Disposal — Sussex County Sussex County | Not published* | Not published* | DNREC lists this separate Sussex County contact for septic-system wastewater disposal work. |
| Div. of Water Licensing | Not published* | Not published* | Use this DNREC licensing contact for onsite wastewater professional license questions or if you cannot use Digital DNREC ePermitting. |
| Septic System Permits | Not published* | Not published* | DNREC's main contacts page lists this subject-matter phone number specifically for septic system permits. |
* Not published: the official page doesn't list it. Call the office to confirm before you rely on it.
What to do next
- Hire the Class D soil scientist first, because Delaware's approval sequence starts with the site evaluation.
- Before hiring anyone else, use DNREC's license page or Digital Resources page to confirm the professional is on the state's current licensee lists.
- Budget for both the DNREC site-evaluation fee and the construction-permit fee, because both appear on the statewide fee schedule.
Not seeing your county office or county?
Not every county office publishes its rules online. Try these, in order:
- General Start with the statewide information above.
- Closest verified Nearest places where we have verified local data outside this state (distance from Delaware's population center, for comparison only):
- Chester County Health Department Permits for On-Lot Sewage Disposal Systems, Pennsylvania · about 49 miles
- Chester County Sewage and Water Staff Coverage Map, Pennsylvania · about 49 miles
- Burlington County Health Department - Environmental Health, New Jersey · about 63 miles
- Call to confirm Ask the official office.DNREC Septic Systems
Website →Phone not shown: use the contact page on the official website above.Your city or county office: Local governments →Not sure who handles it locally? USAGov's free help line, 1-844-872-4681, or the Delaware page on USA.gov can point you to the right office. - Know the current info? Tell us with a link to the official page.