Minnesota Administrative Rules

4725.5850 COMMUNITY PUBLIC WATER-SUPPLY WELLS.

Subpart 1.

Requirements.

In addition to the requirements of parts 4725.2010 to 4725.5825, a public water-supply well used to provide water for a community water system must comply with the requirements in subparts 1a to 8.

Subp. 1a.

Approval of plans and specifications.

A licensee must not construct or materially alter a well, including adding or removing casing below the frost line for a well providing water to a community water system, until plans and specifications have been approved according to part 4720.0010.

Subp. 2.

Site approval.

A licensee must not construct a well for a community public water system until the site has been approved by the commissioner.

Subp. 3.

Contamination sources.

A well for a community public water system must be located according to the distances specified in parts 4725.2150, 4725.2185, 4725.4350, and 4725.4450, but in no case less than 50 feet from a source of contamination except:

A.

the minimum isolation distance is 20 feet for contamination sources listed in part 4725.4450, subpart 1, item G, subitems (2), (3), (8), (9), (11), and (12);

B.

the minimum isolation distance is 20 feet to an aboveground petroleum storage tank holding less than 1,100 gallons used for emergency pumping of a community public supply well if the petroleum storage tank:

(1)

is located in a room or building separate from the community well; and

(2)

is of double-wall construction with leak detection between the walls; or

(3)

is protected with secondary containment according to part 7151.5400;

C.

the minimum isolation distance is ten feet for contamination sources listed in part 4725.4450, subpart 1, item H, subitem (1); and

D.

there is no minimum distance to a pipe or conduit carrying only clear water from a floor drain in a community well house to a gravel pocket or French drain.

Subp. 4.

Flood protection.

A.

The established ground surface at the well site must be at least two feet above the highest known water elevation of a lake, pond, river, stream, or other body of surface water, the waters of which at the highest level would approach to within 50 feet measured horizontally of the well.

B.

The established ground surface must be sloped to drain away from the well and be graded to prevent the accumulation and retention of surface water within 50 feet of the well. Filling must be protected from erosion by riprap or other suitable means.

Subp. 5.

Casing height.

The casing or casing extension must extend vertically at least 12 inches above the established ground surface, floor, or slab according to part 4725.2250, subpart 11.

Subp. 6.

Casing vent.

Casing vents must be constructed in accordance with parts 4725.4850 and 4725.5450 and terminate a minimum of 18 inches above the established ground surface or floor of a building as specified in part 4725.2175.

Subp. 7.

Property ownership or easement required.

The owner of a community public water-supply well must own or legally control, through a permanent easement, the property within a 50-foot radius of the well.

Subp. 8.

Radial water collectors.

Projection of radial water collectors must be in areas and at depths approved by the commissioner.

A.

The exact location of caisson construction joints and porthole assemblies must be indicated on the submitted plans.

B.

The caisson wall must be reinforced.

C.

Procedures must be used that assure minimum vertical rise of the collectors.

D.

The top of the caisson must be covered with a watertight floor.

E.

Pump or other openings through the floor must have a minimum four-inch high curbing.

F.

Pump discharge piping must not be placed through the caisson walls.

G.

There must be no construction joint within 15 feet of the established ground surface.

Statutory Authority:

MS s 103I.101; 103I.111; 103I.205; 103I.221; 103I.301; 103I.401; 103I.451; 103I.501; 103I.525; 103I.531; 103I.535; 103I.541; 103I.621; 144.05; 144.12; 144.383; 157.04; 157.08; 157.09; 157.13

History:

17 SR 2773; 33 SR 211

Published Electronically:

September 2, 2008