Iowa Admin. Code r. 567-49.8 - Well location and separation distances (SDs)

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(1) Wells shall be located with consideration given to the lot size; soil contour, porosity, and absorbency; local groundwater conditions; flooding; publicly available geologic data including but not limited to well logs; and other factors necessary to implement the rules.

a. Frost pits. Wells cannot be located within frost pits. Frost pits that do not contain wells are allowed for the purpose of housing other appurtenances, such as pressure tanks and valves, provided the frost pits are not located closer than ten feet from any well.

b. Relation to buildings. Wells shall be located so that no building interferes with reasonable access for cleaning, treatment, repair, testing, inspection, or other maintenance. Wells cannot be located in basements.

c. Easements. No well shall be located on a property not owned by the well owner unless an easement allowing such placement is reviewed and approved by the administrative authority and the easement is legally recorded.

(2) The following minimum lateral SDs in Table I below from all private wells shall apply for the common structures or sources of contamination listed in the table. The lack of specific distances to other possible sources of contamination, such as refuse disposal sites and high-pressure gas lines, does not minimize their potential hazard. Other possible sources shall be evaluated in each particular situation and a distance arrived at that is based on pertinent facts. The well contractor shall consult the administrative authority for assistance in determining a proper distance in such cases.

TABLE I: Private Well Separation Distances

Structure or Source of Contamination	Required Minimum Lateral Distance, as Measured Horizontally on the Ground Surface, in feet
	Private Wells
	Deep Well¹	Shallow Well¹
WELLS:
Public wells:
Public water supply well - deep or shallow	200	400
Below-ground level finished water storage facility	50
Private wells:
Existing private wells that do not conform to 567-Chapter 49	100
Existing private wells that conform to 567-Chapter 49	10
WASTEWATER DISPOSAL SYSTEMS:
PSDSs and onsite treatment systems - closed portion²	50
PSDSs and onsite treatment systems - open portion²	100
Wastewater treatment works^3,4,5	400
CHEMICALS:
Transmission pipelines (including but not limited to fertilizer, liquid petroleum, or anhydrous ammonia)⁶	100	200
Chemical and mineral storage or preparation areas, including areas for spray materials, commercial fertilizers, or chemicals that may contaminate groundwater, except for liquid propane gas (LPG)	150
Liquid hydrocarbon storage tanks, except for LPG	100
LPG storage tanks	15
ANIMALS:
Animal enclosures (such as confinement buildings or open feedlots)	100	200
Animal Wastes:
Storage basins or lagoons, or runoff control basins	1000⁵
Solids stockpiles, solids settling facilities, or storage tanks	100	200
WATERBODIES:
Flowing streams, ponds, lakes, reservoirs, wetlands, or drainage channels⁷	25
MISCELLANEOUS
Anaerobic lagoons⁵	1000⁸
Solid waste landfills and disposal sites⁸	1000
Roadside ditches and road rights-of-way	15
Cisterns, well pits (containing a well head), yard hydrants, or frost pits	10
Property lines⁹	4
Land application of septage¹⁰	500
Land application of sewage sludge	200
CONVEYANCES:¹¹
Gravity sanitary sewers and sanitary sewer force mains including those carrying water treatment plant wastes:
Water main materials¹²	25¹³
Standard sanitary sewer materials¹²	50¹³
Storm sewers, general minimums	10
Independent clear water drains or pump house floor drains	10
Building sewer service lines and laterals¹⁴	10

¹Deep and shallow wells are defined in rule 567-40.2 (455B).

²PSDS (private sewage disposal system) is defined in 567-subrule 69.1(2). For the purposes of this table, "onsite treatment system" includes any wastewater treatment system not included in the definition of a PSDS (i.e., provides treatment or disposal of domestic sewage from more than four dwelling units or 16 or more individuals on a continuing basis) that is utilizing wastewater treatment technologies described in 567-Chapter 69 to treat domestic waste. Closed portion refers to the part of a treatment system that is fully contained and does not allow effluent or pretreated effluent to enter soil or groundwater (e.g., septic tank or impervious vault toilet). Open portion refers to the part of a treatment system that allows effluent or pretreated effluent to discharge into soil or groundwater for treatment or disposal (e.g., soil absorption system or unlined ISSF system). These SDs also apply to septic systems that are not considered privately owned.

³For the purposes of this table, "wastewater treatment works" includes lagoons and mechanical treatment plants as described in this superscript. The term "lagoons" includes aerated lagoon systems, advanced aerated lagoon systems, and waste stabilization lagoons, as defined in 567-subrule 81.1(1), and holding ponds, equalization basins, and sludge digestion or holding tanks, as described in the Iowa Wastewater Facilities Design Standards (IWFDS). The term does not include lagoons used to dispose of water treatment plant wastes and anaerobic lagoons used for animal wastes (as noted in superscript 5). The SD from lagoons shall be measured from the water surface. The term "mechanical treatment plants" includes activated sludge systems and fixed film biological treatment systems, as defined in 567-subrule 81.1(1), and any other wastewater disposal system that is not a PSDS, an onsite treatment system, or a lagoon.

⁴The SD between an existing, nonpotable, deep or shallow private well and an industrial treatment works may be reduced from 400 feet to 200 feet to accommodate the expansion of an existing industrial treatment works, provided the well and the treatment works share the same ownership.

⁵The 400-foot SD between a private well and an anaerobic lagoon, earthen manure storage basin, earthen manure slurry storage basin, or runoff control basin shall be 1,000 feet. If an applicant for a private well construction permit demonstrates through percolation testing that the seepage loss through the lagoon or basin does not exceed 1/16 inch per day (0.0625 inch/day), the SD shall be 400 feet. The percolation test shall meet the requirements of ASTM D1587/D1587M-15 and 567-subrule 65.15(11).

⁶These private well SDs apply only if a more restrictive setback is not set by the pipeline owner.

⁷Includes drainage channels that may have a direct connection to the groundwater table or a surface water.

⁸Solid waste, when referring to landfills and disposal sites, means garbage, refuse, rubbish, and other similar discarded solid or semisolid materials, including but not limited to such materials resulting from industrial, commercial, agricultural, and domestic activities.

⁹This distance applies unless a mutual easement is signed and recorded by both parties.

¹⁰Septage shall be land applied in accordance with 567-Chapter 68.

¹¹The SDs are dependent upon two factors: the type of piping that is in the existing sewer or drain, as noted in the table, and that the piping was properly installed in accordance with the standards.

¹²These are the type of materials or pipe used to construct the type of sewer, main, or drain as specified, in accordance with 567-subrule 43.3(2) and Section 2.4 of the IWFDS.

¹³The 25- and 50-foot SDs do not apply to private closed-loop geothermal wells. The SD between closed-loop geothermal systems and both gravity sanitary sewers and sanitary sewer force mains shall be 10 feet.

¹⁴The SD for building sewer service lines and laterals shall be considered the minimum distance when constructing sewer lines and shall be increased where possible to provide better protection.

Notes

Iowa Admin. Code r. 567-49.8

Adopted by IAB May 14, 2025/Volume XLVII, Number 23, effective 6/18/2025

State regulations are updated quarterly; we currently have two versions available. Below is a comparison between our most recent version and the prior quarterly release. More comparison features will be added as we have more versions to compare.

(1) Drilled wells.

a. Drilled wells in unconsolidated materials.

(1) Depth. In no case shall less than 20 feet of permanent casing be installed in wells drilled in unconsolidated materials. If the alluvial aquifer where the water is to be drawn from is covered by less than 40 feet of low permeability materials, the well screen shall be set at the bottom of the water-bearing aquifer or at least 60 feet from the surface. (Deeper depths may be required if nitrate contamination is excessive.) If more than 40 feet of low permeability materials are present above the aquifer, the casing shall extend down at least to the top of the aquifer.

(2) Grouting. Grout shall be placed to a minimum depth of 40 feet or along the full length of the casing where less than 40 feet of casing is set. Grouting the full length of the casing below 40 feet may be necessary to isolate any contaminated water lenses or aquifers. If a layer of low permeability material at least 5 feet thick is encountered less than 40 feet from the surface, the grout may be terminated no less than 5 feet below the top of this low permeability material, but in no case less than 20 feet from the ground surface. Grout must be placed in accordance with 49.9(3), except when driving casing. When driving casing a #8 mesh bentonite or bentonite grout must be maintained around the outside of the casing. The bottom of driven casing must be equipped with a drive shoe.

(3) Annular space. The diameter of the borehole shall be at least 3 inches greater than the outside diameter of the well casing to the minimum grouting depth. When steel well casing pipe is installed using percussion methods, the annular space shall be at least 5 inches greater than the outside diameter of the well casing to a minimum depth of 25 feet.

(4) If the depth of casing is greater than 40 feet, the annular space below 40 feet may be filled with heavy drilling fluid taken from the borehole as long as the top 40 feet of annular space is properly grouted. In this case, the annular space below 40 feet shall be kept as small as possible to avoid settling.

b. Drilled wells in consolidated material.

(1) Minimum casing depth. Casing shall extend to a depth of at least 40 feet and be seated in firm rock. When the uppermost bedrock consists of creviced limestone or dolomite that does not produce water, the casing shall extend through the creviced formation, be seated in firm rock and be properly grouted.

(2) Grouting. For bedrock wells, full-length grouting of the casing is strongly recommended. Grout shall be placed to a minimum depth of 40 feet in accordance with 49.9(3), except when driving casing using percussion or casing-hammer/rotary drilling. When driving casing, #8 mesh bentonite or bentonite grout must be maintained around the outside of the casing. The bottom of driven casing must be equipped with a drive shoe. If a layer of low permeability material at least 5 feet thick is encountered less than 40 feet from the surface, the grout may be terminated no less than 5 feet below the top of this low permeability material, but in no case less than 20 feet from the ground surface. Where local conditions warrant, the administrative authority may require more extensive grouting to protect any aquifer(s) that are penetrated.

(3) Annular space. The borehole shall be at least 3 inches greater than the outside diameter of the well casing for the upper 40 feet or the minimum grouting depth. When steel casing pipe is installed using percussion, or casing-hammer/rotary methods, the annular space shall be at least 5 inches greater than the outside diameter of the well casing to a minimum depth of 25 feet. When bedrock wells are full-length pressure-grouted through the casing, the borehole diameter shall be 3 inches larger than the outside diameter of the casing for the minimum depth of at least 25 feet.

(5) In fractured rock, where circulation of slurry cannot be maintained, grouting may be done with bentonite chips. The chips shall be hydrated with one gallon of water per bag of bentonite.

(2) Bored and augered wells in unconsolidated materials. For bored or augered wells with concrete or clay tile casings at least 18 inches in diameter, buried-slab construction is required.

a. Casing. The concrete or vitrified clay pipe casing shall be terminated not less than 10 feet below ground surface and extend to a minimum depth of 20 feet. The casing shall be fitted with a reinforced concrete or steel plate into which a watertight steel or thermoplastic casing is firmly imbedded in or connected to a pipe cast or welded into the plate. This casing shall be at least 5 inches in diameter and shall extend from the plate to not less than 12 inches above established grade or the 100-year flood level, whichever is higher. A pitless adapter shall be installed below frost depth on the newly installed plastic or steel casing.

b. Backfilling annular space. A 12-inch grout seal shall be poured over and around the plate. The annular space between the steel or thermoplastic casing and the borehole shall be backfilled with clean compacted soil free of debris or large organic material. During the backfilling process, the earth shall be thoroughly tamped to minimize settling. Grading around the well shall then be accomplished in accordance with subrule 49.7(2).

(3) Driven and direct push wells. Sandpoint wells are typically constructed in sandy areas with a high water table. Groundwater in these areas is often susceptible to contamination. This type of construction is not recommended for potable water supply. Sandpoint wells shall meet the requirements of this chapter except for casing depth and grouting requirements.

(4) Flowing artesian wells. Drilling operations shall extend into but not through the formation confining the water. The casing shall then be installed and the annular space full-length pressure-grouted and allowed to set. After the grout is set, the drill hole shall be extended into the confined water-bearing formation. Flow control from the well shall be provided by valved pipe connections or a receiving tank set at an altitude corresponding to that of the artesian head. Under no circumstances shall the water flow uncontrolled to waste. A direct connection between the discharge pipe and a receiving tank, sewer, or other source of contamination is prohibited.

Notes

Iowa Admin. Code r. 567-49.8