Septic Tank & Field Clearance Distances to Water WellsClearances or isolation distances for septic tank, drainfield, soakaway bed, & wells:
Septic tank or field setbacks & clearances for septic systems to wells, buildings, property lines, & distances to other site features. Well setbacks & clearances to septics, property lines, buildings, etc.
In this article, a detailed septic distances table describes distance requirements between septic components (septic tank, leach field, cesspools, drywells) and other site features such as wells, water supply piping, streams, trees, property boundaries, lakes, etc.
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In general, septic effluent must be disposed of on the property from which it originates.
However stricter clearances and distances than this are required between various onsite wastewater treatment system components and buildings, property boundaries, lakes, streams, wells, and so on, as detailed in the table below. Contact us with corrections or additions to this data.
Photo above: this is what happens when you dig down to install a swimming pool too close to the septic drainfield.
These septic component clearance distance tables below give distance requirements between septic components and wells, streams, trees, property boundaries, lakes, etc.
Common guidelines require at least 50' clearance distance between a well and a septic system tank or 150' between a well and a septic drainfield or leaching bed but you will see that different authorities may recommend different distances.
Local soil and rock conditions can make these "rules of thumb" unreliable. See "One and Two Family Dwelling Code, Section P-2510-Combined Seepage Pits and Disposal Fields," and Table P-2504, "Location of Sewage Disposal System." Other references are cited at the end of this table.
Table 1a Septic System Component Clearance Distances (in feet) from Wells, Buildings, & Other Site Features |
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Site Feature / Component (below) |
Sewer Line Distance |
Septic D-Box | Other Sanitary Code Specifications | General SEPTIC COMPONENT LOCATIONS |
||||
| MASSACHUSETTS TITLE 5 |
||||||||
Authority or Model Code --> |
General / TYPICAL6 |
General | General / TYPICAL |
General / TYPICAL |
FL Florida |
MA Title 5 Massachusetts |
NY New York |
More Information |
| Cistern | 25 | 25 | 25 | - | - | - | CISTERNS, WATER STORAGE | |
| Drainfield, Soakbed, Soil Absorption System above high groundwater (water table) or "depth to groundwater" | 4 - 5 ft. to > 10 ft. | - | - | 4 ft |
Allowable depth from bottom of soakbed trenches to seasonal high groundwater level Distance must be greater in coarse gravelly soil Distance may be as little as 5 ft. in fine soils passing the #200 sieve test. 8-1 Where fill is used, measure clearance distances from the edge or toe of the fill. |
|||
| Drainfield, Soil Absorption Sys. Minimum Area | 150 | - | - | - | - | |||
Drainfield, SAS Other |
20 | - | - | - | - | |||
| Dry gulch | 10 | 256.2 | - | |||||
| Embankment top or Cuts >= 2ft hgt |
20 | - | - | - | - | |||
| Intercept drain up-slope |
10 | - | - | - | - | |||
| Intercept drain down-slope |
26 | - | - | - | - | |||
| Lake, watercourse, stream, wetland [high water line] |
50 | 100 | 75 | 100 6.2 50 OH10 |
75 ft | 50 | - | Use the water-body high-water mark as its boundary. OH - Ohio code |
| Neighboring residence | 5 | 200 | - | - | - | - | ||
| Property Line | 5 - CA, FL, WA 10 - MO |
10 | 10 | 10 50 OH10 |
10 | 5 | CA-California NEIGHBORING SEPTIC SYSTEM PROBLEMS |
|
| Septic Tank cover soil backfill min" - max" |
6"-?" | - | 12"-24" | - | - | |||
| Sinkhole or drainage well | 25 12 | 300 OH10 | Reduced to 100 ft if a permanent vegetative buffer is maintained around the sinkhole or drainage well |
|||||
| Surficial Sinkhole Edges | 500 | - | - | - | - | |||
| Spring | 50 | 50 | 100 2006.1 .2 .4 |
- | - | - | - | |
| Stream or open ditch | 50 | 25 | 25 | For non-classified streams 11 | ||||
| Stream or open ditch | 50 | 50-100 | For classified streams | |||||
| Structures to Septic Tank / Leach field [Occupied] |
5 CA, FL 10 NY |
20 | 5 - general |
20 | 5 ft | 8 ft | - | CA - California, FL - Florida code MO - Missouri, NY - New York code |
| Structures to Sewer Line [Occupied] |
5 | 2 | ||||||
| Subsoil drain line | 10 | 10 | 25 | |||||
| Swimming Pool | 5 - FL | 5-FL 15-MO |
- | - | - | SEPTIC to POOL DISTANCE | ||
| Trees, large | 10 | - | ? | - | PLANTS & TREES OVER SEPTIC SYSTEMS | |||
| Water supply piping [Potable] |
10 | 10 | 25 | 10 | - | - | Closest part of wastewater treatment >= 10 ft. to any water piping | |
| Water Supply Piping under suction |
50 | 50 | 100 2006.1 .2 .4 |
- | - | - | - | |
Water well, Private, or well suction line |
25 (cast iron) or 50 other |
100 | 50 - MO 75 - FL |
10010 2006.1 .2 .4 |
75 | 100 | 50 |
Note that clearance distances from any septic system component such as septic effluent line tank to D-box and particularly including the drainfield, leachfield, soakaway, soakbed, or other synonyms for sewage effluent disposal will vary additionally in some jurisdictions according to 8-1 - The soil type. Rocky or sandy soils require greater setback distances from well to septic - The soil grade or slope and location of a water well that is down-slope from the septic system, Well separation distances from contaminant sources are increased by 50% whenever aquifer water enters the water well at less than 50 ft. below grade or additional measures to prevent contamination must be added. |
| Water well, Public or Drinking water surface water intake |
200 300 - MO |
1500 OH10 | 200 | - | 100 ? | |||
Water well |
50 | 100 OH10 | 50 | - | - | |||
...
Table 1b - Cesspool / Seepage Pit |
|||
| Site Feature / Component (below) | Sewer Line Distance |
NY Code |
More Information |
| Cesspools min. freeboard | 2ft | 6" | CESSPOOLS |
| Minimum volume | 500 | 1/2 day | - |
| Separation from Surface Water Supply | 150 | 100 | - |
| Separation from private well or suction line | 150 | 50 | - |
| Separation from private well, bad sample | 50-100 |
Readers will find more details about septic system clearances and issues
at NEIGHBORING SEPTIC SYSTEM PROBLEMS.
Below we provide additional septic system component clearance distances when advanced septic system designs or other special components are in use.
Table 2a Advanced or Special Septic System Component Clearance Distances (in feet) |
||||||
Site Feature / Component |
Septic Holding Tank / Vault | Lagoon Distance LAGOON SEPTIC |
Lined Evap/Trans or Lined Pond |
Advanced Treatment or Greywater System |
Other Sanitary Code Specifications |
General SEPTIC COMPONENT LOCATIONS |
Authority or Model Code |
General / TYPICAL1 |
MO Missouri |
CO Colorado |
CO Colorado |
UPC Uniform Plumbing Code |
More Information |
| Cistern | 10 | 25 ft | 25 | 25 | - | CISTERNS, WATER STORAGE |
| Drainfield, Soakbed, Soil Absorption System above high groundwater (water table) |
- | - | SEPTIC DRAINFIELD SHAPE | |||
| Drainfield, Soil Absorption Sys. Minimum Area | - | 150 | - | |||
| Drainfield, SAS Other (Except for future repair area) |
20 ft | - | - | |||
| Dry gulch | 10 | 10 | 256.2 | |||
| Embankment top or Cuts >= 2ft hgt |
20 ft | - | - | |||
| Intercept drain up-slope |
10 ft | - | - | |||
| Intercept drain down-slope |
25 ft | - | - | |||
| Lake, watercourse, stream, wetland [high water line] |
50 | 25 ft | 50 | 506.2 | - | |
| Neighboring residence | 200 ft | - | - | |||
| Property Line | 75 | 10 | 10 | NEIGHBORING SEPTIC SYSTEM PROBLEMS | ||
| Septic Tank cover soil backfill min" - max" |
- | - | - | |||
| Sinkhole | - MO | Nowhere in the drainage area of a sinkhole | ||||
| Surficial Sinkhole Edges | 500 | - | - | |||
| Spring | 50 | 100 | - | - | ||
| Structures to Septic Tank / Leach field [Occupied] |
100 ft | 15 | 20 | 10 ft | - | |
| Structures to Sewer Line [Occupied] |
||||||
| Subsoil drain line | 10 | 10 | 25 | |||
| Swimming Pool | 100 | - | SEPTIC to POOL DISTANCE | |||
| Trees, large | - | - | PLANTS & TREES OVER SEPTIC SYSTEMS | |||
| Water supply piping [Potable] |
10 | 10 | 10 | 25 | - | - |
| Water Supply Piping under suction |
50 | 100 | - | - | ||
Water well, Private |
50 | - | 60 | 1006.2 | - | WELL LOCATION, HOW TO FIND |
| Water well, Public | 300 | - | ||||
Water well |
- | - | ||||
Table 2b - Special Cesspool or Seepage Pit Clearances and Specifications |
Feet | Notes |
| Cesspools min. freeboard | 2 | CESSPOOLS |
| Minimum volume | - | |
| Separation from Surface Water Supply | 150 | - |
| Separation from private well | 150 | - |
| Separation from private well, bad sample |
Readers will find more details about septic system clearances and issues at NEIGHBORING SEPTIC SYSTEM PROBLEMS.
Table 3 Septic Component Clearance Distances to a Water Well According to Soil Type & Septic System Type |
|||||
| Soil Conditions 1 | Depth from SAS Bottom to Groundwater Seasonal High Level 2 | Septic Filter Trench Type & Distances to Water Well in Feet |
Comments | ||
| TYPE I Gravity-fed @ Normal Loading 3 |
TYPE II Pressure-Dosed @ Normal Loading 3 |
TYPE III Pressure-Dosed @ Low-Loading 4 | |||
| Very coarse gravelly soil < 5% Fines5 | 4 to 5 ft. | Not Allowed | 200 ft. | 150 ft. | Soil properties in other geographic locations and in other sewage code jurisdictions will differ and may have different allowable septic system clearance distances than our examples given here. |
| > 5 ft to 10 ft | 200 ft. | 150 ft. | 100 ft. | ||
| > 10 ft. | 150 ft. | 100 ft. | 100 ft. | ||
| Coarse sandy soil, 5 to 15% Fines | 4 to 5 ft. | 200 ft. | 150 ft. | 100 ft. | |
| > 5 ft to 10 ft | 150 ft. | 100 ft. | 100 ft. | ||
| > 10 ft. | 100 ft. | 100 ft. | 100 ft. | ||
Table 4 Cesspool or Seepage Pit, Raised / Mound Septic, Sand Filter Septic Special Clearance Distances |
|||||
| Clearance Distances For |
Depth of System Bottom to Groundwater Seasonal High Level (1) |
Well or Suction Line (6)(8) |
Stream Watercourse (3) or Lake |
Dwelling | Property Line |
| Seepage Pit | 3 ft. | 150 ft. | 100 ft. | 20 ft. | 10 ft. |
| Raised or Mound Septic | 100 | 100 | 20 | 10 | |
| Intermittent Sand Filter Septic | 100 | 100 | 20 | 10 | |
| Non-Waterborne System, Offsite Discharge | 50 | 50 | 20 | 10 | |
| Non-Waterborne System, Onsite Discharge | 100 | 50 | 20 | 10 | |
...
Below you will find questions and answers previously posted on this page at its page bottom reader comment box.
How close can you build a garage to a holding tank. And does a holding tank have a septic field in most cases or no ? On 2022-06-06 by Alice A Smith
by InspectApedia-911 (mod)
@Alice A Smith,
Septic tank distance to a structure isn't given uniformly across jurisdictions (you don't specify country, city, province, state &c.) but is typically 10 ft.
A holding tank is just that: it "holds" or "stores" wastewater. It does not let anything out. The holding tank has to be emptied by a septic pumping contractor.
Holding tanks are prohibited (illegal) in nearly all jurisdictions except by special permit, such as perhaps a restaurant built along the edge of a river or stream.
See details
at HOLDING TANK SEPTIC SYSTEMS
I want to build a garage above ground. How far does it need to be from the leech area of septic system? On 2020-06-12 by john Herod
by (mod) -
John
The clearance distance between your garage walls and drive to it need to be (typically) 5 ft to 20 ft. depending on local codes where you live. Most states in the U.S. want 20 ft. but some permit much closer clearances.
Watch out: even if you meet the garage setback to septic drainfield, be sure that your builder, in the course of putting up the garage, doesn't drive equipment over the leachfield or it may be damaged or ruined.
We Are installing an above ground pool. We want to measure the distance from the mound to the pool to make sure we’re in compliance. What are the two points from which we measure On 2022-04-13
by Denise ryan
Just above is our (DF) Photograph of a swimming pool installed too close to a septic drainfield - in failure
by Inspectapedia Com Moderator (mod) - installing an above ground pool
@Denise ryan,
You measure the closest point of pool or any pool equipment to the closest bottom edge of the septic mound.
But there's more to consider. Be sure that the contractor building the pool doesn't drive equipment over the mound as that will damage it.
And be sure that any swimming pool discharge, such as when you are backwashing the filter or emptying the pool, is directed away from the mound.Be sure to read the details at SEPTIC to POOL DISTANCE
Why do they say that a potable water supply line should be 10-25 feet from a septic drain field? Is is because the water pipe may break and flood the drain field? On 2022-02-16 by Raquel B
by Inspectapedia Com Moderator (mod) - potable water supply line should be 10-25 feet from a septic drain field
@Raquel B,
More likely the concern is that a leak in supply piping combined with a temporary loss of pressure or even exposure during its installation risks contamination of the water supply, poisoning or sickening building occupants.
The setback of a mound from a private well is measured from _______ of the mound? Is it the highest point can't seem to find a answer - On 2021-12-22 by Bigzasty@yahoo.com
by Inspectapedia Com Moderator - private well distance to mound: measure from toe of the mound-fill
@Bigzasty,
Clearance distances are typically measured from the site feature (the private well in your case) to the nearest edge of the toe or edge of fill that was used to construct the mound or raised-bed septic drainfield area or trench, soak-pit, soakaway bed, MOUND, or raised bed.
What that clearance distance will need to be are defined in the tables above on this page and depend on various factors such soil type and septic system type.
i found the drain tank or leach field for water what would the distance be to the soils tank On 2020-12-13 by kelly sims
by (mod) - septic drainfield distance to septic tank soils tank
Kelly
There is no fixed dor standard istance involved and the location as well as distance world pretty much always be site dependent. However if you found any component of the septic system your plumber can insert a sewer line camera or other grain locating equipment in order to follow the lines to the septic tank or distribution box
Normal distance from septic to D box in NK RI On 2020-11-28 by Jim
Reply by (mod) -
The distance from the tank to the D boxes site dependent but typically is 10 to 75 feet
Any recommendations on appropriate distance for a leachfield from an already established cemetery on the same property? On 2020-07-19 by Carol
by (mod) -
Carol
Thank you for an interesting question.
I doubt that there is a single "right answer" to separation distance of septic drainfields or leachfields and cemeteries as there are quite a few variables such as terrain shape, soil properties, cemetery activity.
What problem are we avoiding: the obvious one at first glance might simply be avoiding any risk of sewage effluent showing up in an excavation for a grave. To be totally safe you'd use the same setbacks as for a well or water source. Typically that's 100 ft. or more.by Carol
Yikes--not sure we have that much space. But yes, that's the biggest concern. So, thanks.
How far does the well have to be from the septic system for a VA loan qualification. On 2020-05-20 by billieallen
by (mod) -
BillieAllen:
In the U.S. the VA has not specified setbacks between well and septic; but the property certainly should meet your local and state requirements.Those vary a bit depending on the property location, but 100 feet separation between well and septic is reasonable.
How close can an in-ground 250 gal propane tank be buried to a septic drain field? On 2020-03-06 by Mark Berger
by (mod) -
Mark
I don't think we'll find a septic nor propane tank code that addresses the distance relationships between those two systems, but it would make sense to
1. be dead sure that nobody drives heavy equipment over your drainfield
2. keep excavation for the buried propane tank far enough away from the drainfield that you won't disturb the drainfield by the excavation, installation, soil piles, backfilling, trenching for buried gas lines, etc.
How far does a shed have to be from aerobic spray heads ? On 2020-02-02 by Jim
by (mod) -
OPINION:
Jim,
The footprint of the shed ought not be in the spray area at all;
Beyond that it needs to be far enough away so as not to be sprayed.
How far does a 100 foot deep well have to be from my septic tank ? On 2020-01-14 by bob dubois
Bob
you're on the correct web page, and the well clearance distances to septic are given above. The well depth doesn't change that General guideline.
however one could infer an important point from your question. That is one might think that a deeper well is indeed less likely to suffer contamination from a source close to the ground surface, such as a drain field for septic tank. However I think without extremely specific site to tell that's not something you can count on.A lot depends on the Underground soil conditions, Rock, local water tables Etc.
Moved to CALIFORNIA SEPTIC REGULATIONS FAQS
...
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