Septic Systems

A septic system or on-site wastewater treatment system (OWTS) is a self-contained, underground wastewater treatment system, most often utilized in rural areas.

The standard septic system involves a septic tank (to hold wastewater from drainpipes until solids settle out in the tank) and a system of pipes that distributes the remaining liquid waste underground over a large area — the leach field. The goal is to make sure that this filtration through the soil is sufficient to clean the wastewater before it reaches drinking water, well sources, or surface waters.

Building in a floodplain? All development within designated flood plains requires a permit from the Delta County Environmental Health Division prior to installing any septic system. The property owner is responsible for ensuring this determination takes place. If you think that you will be building in or near a flood plain, you can easily search for the floodplain status on FEMAs website by clicking here. Floodplain FIRIM (Flood Insurance Rate Maps) are downloadable by clicking hereOr contact Environmental Health at 874-2165 to obtain information regarding flood plain development. A flood plain application is required (Click here for a fillable PDF) and a checklist is available for developers to guide the process. The floodplain application fee is $250.00.

State and county laws require that a septic permit is to be issued by the department prior to installing, constructing, or making repairs to a septic system.

New Systems:

Completed applications (below) should be returned to the Delta County Health Department. Please note that you must apply for and obtain the Access/Address Permit before obtaining the on-site wastewater treatment system (ISDS) permit "Final Approval." For more information, see the Application Checklist (below), Development Application and Development Permit Fact Sheet.

Documents to get you started:

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2021 Engineering Firms

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2021 Septic Permit (OWTS) Checklist

2021 Septic Permit (OWTS) Complete Application


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Installers and Cleaners List

Repairs, Alteration, and Replacement Systems 

All major repairs, replacements, alterations of existing OWTS require a permit. An on-site wastewater treatment system (OWTS) application must be filled out and submitted to the Delta County Health Department prior to construction. For more detailed information, see the OWTS Instructions

Soil icon Opens in new windowSoils and Site Evaluation Application

The Engineer evaluates the soil porosity and permeability for the installation of on-site wastewater treatment system (OWTS). This application is used for vacant undeveloped land and does not serve as permit to install an OWTS

Related Forms and Information 

Return to the Planning and Community Development web page

Return to the Environmental Health Department web page.