Virginia Administrative Code › Title 12 - HEALTH › Agency 5 - DEPARTMENT OF HEALTH › Chapter 630 - PRIVATE WELL REGULATIONS › Part III - Design and Construction Criteria › Article 1 - General Requirements › Section 12VAC5-630-410 - Construction; general

Current through Register Vol. 40, No. 24, July 15, 2024
A. Casing.
1. Class IIIA wells shall be cased to a depth
					 of at least 100 feet.
2. Class IIIB
					 wells shall be cased to a depth of at least 50 feet.
3. Except as provided in subdivisions a
					 through e below, all Class IIIC and IV wells shall be cased to a minimum depth
					 of 20 feet or terminated not less than one foot in bedrock when bedrock is
					 encountered at a depth less than 20 feet.
a.
					 When in collapsing material, the casing shall terminate in the aquifer but in
					 no instance be less than 20 feet.
b. Where an aquifer is encountered at less
					 than 20 feet, Class IV wells may be cased to within one foot of the water
					 bearing strata. In the instance of Class IV wells the intent of this chapter is
					 to protect ground water quality, and not to ensure a potable water supply.
Exception: Class IV wells placed closer than 50 feet
						from a building foundation treated with a chemical termiticide or other
						pesticide shall comply with the minimum casing depth requirements of
						12VAC5-630-380 F 2.
c. Alternate casing depths may be
					 accepted for bored wells when the only aquifer lies between 11 and 20 feet
					 provided the casing is placed within one foot of the aquifer and must not be
					 less than 10 feet in depth from the ground surface.
d. Class III C driven wells shall be cased to
					 the water bearing strata; however, in no case less than 10 feet. No minimum
					 casing requirements apply to Class IV driven wells except that in order to
					 protect ground water they shall be capable of meeting the minimum grouting
					 requirements as described in subdivision C 5 e of this section.
e. Closed-loop ground-source heat pump wells
					 do not have to be cased.
4. All private well casings shall be extended
					 at least 12 inches above ground or 12 inches above a concrete floor in well
					 house with a gravity flow drain. The following wells are exempted from this
					 requirement; however, their location shall be permanently marked for easy
					 location in the future:
a. Drilled shallow
					 well suction pump systems that will not operate unless a vacuum is maintained.
					 The casings for these wells are also the suction lines through which water is
					 drawn.
b. Deep well ejector pump
					 systems that utilize a casing adaptor and must maintain a vacuum to
					 operate.
c. Closed-loop
					 ground-source heat pump wells.
d.
					 Heat pump return wells that are completely sealed.
5. All steel casings shall meet or exceed the
					 material specifications found in
					 12VAC5-630-480.
6. No plastic well casing shall be installed
					 which will exceed 80% of its RHCP (resistance to hydraulic collapse pressure).
					 When experience has shown, in the division's opinion, that the prevailing
					 geologic conditions are subject to collapse or shifting, or where heavy clay or
					 unstable backfill materials occur, plastic well casings may not exceed 50% of
					 the RHCP rating. It shall be the responsibility of the well driller to submit
					 calculations to the division demonstrating that individual well casings do not
					 exceed these ratings.