
Onsite design application
Instructions on how to submit online
- Go to Environmental Health's online services portal.
- If you are a new user, click on "First-time users register here."
- If you previously created an account, click on "Registered users log in here."
- Once you are logged in, from the left side menu, click on "OSS plan review."
- Click on "Add OSS Plan Review" and complete the application process and attach your application document.
- After you have completed the application and paid your fee, you will be able to print the application for your records, you will receive a confirmation email, and you can check the status of your application at www.kingcounty.gov/oss/status.
Application document checklist
No. | Type of document | Additional instructions | Conditions that initiate requirement |
---|---|---|---|
1 | Vicinity Map | Must include gate code, presence of dogs, and details needed for the inspector to locate the proposed/existing well & OSS site | Required for all applications |
2 | Detailed Site Plans and specifications | Maximum paper size is 11” x 17” (Detailed site plan: 1” to 20’ or the largest scale that will allow; Overall site plan may be scaled as needed for example, 1” to 50’ or 100’; Sewage Tank Invert & Plumbing Stub Elevations; and Details of proposal per Title 13 Code requirements – remember to check neighboring properties for wells, OSS, and storm water systems | Required for all applications |
3 | Hydraulic Calculations | Should include clear calculations, preferably on a single page | Required for all applications |
4 | Soil Log Data | Minimum of 5 soil logs - 2 each drain field & reserve area + 1 for tank(s) (Remember to document the soil log for the septic tank). If a treatment device, such as a sand filter or ATU unit, is greater than thirty feet from the wastewater tanks, then one soil log shall be located in the area of the treatment device. |
Required for all applications |
5 | Treatment Product Specifications | Document ONLY what is needed for design and installation – documentation that is available in the design manual does not need to be included | Required for all applications |
6 | Critical Area Designation | Required for new On-site sewage design | |
7 | Sewer Letter | Sewer letter should state what the distance from property line to nearest sewer is greater or less than 200 feet | Required for On-site sewage system in urban area |
8 | Valid (one year) water Availability Letter | Required if property is in public water system area | |
9 | Current Bacteria test | If Applicable | |
10 | Nitrate test and Arsenic Result | If Applicable | |
11 | DRAFT well covenant(s) | Required if water source is “Proposed Private Individual Well” | |
12 | Copies of covenants | Required if water source is “Existing Private Individual Well” | |
13 | Proof of lot segregation date | Required if water source is “Proposed Private Individual Well” and property is less than 5 acres. If Drainfield Easement Or if applicable |
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14 | Well construction log | Required if water source is “Existing Private Individual Well” | |
15 | Easement survey | If Applicable | |
16 | Draft Drainfield easement language | Required If Drainfield Easement |
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17 | Draft easement language | If Applicable | |
18 | Other_1 | Optional for any type of applications | |
19 | Other_2 | Optional for any type of applications |