7 Del. Admin. Code § 7301-6.0

Current through Register Vol. 28, No. 4, October 1, 2024

Section 7301-6.0 - Special Construction Requirements

6.1 Monitor and Observation Wells

6.1.1 Well construction materials and methods must be compatible with the monitoring program objectives.

6.1.2 Wells must be constructed to allow for characterization of geologic materials and sampling. The Department may place additional requirements on wells that are used as part of a specific environmental program.

6.1.3 Wells located within a Delaware Department of Transportation (DelDOT) right-of- way must be enclosed in a curb box, flush mounted with the ground surface with a six-inch wide cement apron around the perimeter of the curb box. No well shall be placed on highway travel lanes, on auxiliary travel lanes or on roadway shoulders. The well owner is responsible for having these wells sealed upon notification from either the Department or DelDOT.

6.1.4 Applications for wells in areas described in this Section must have the words "Zone of Interest" clearly marked on the application.

6.1.4.1 Ditches:

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6.1.4.2 Telephone poles and DelDOT fence lines.

6.1.4.3 Two feet between the sidewalk and road from the roadside edge of the sidewalk.

6.1.4.4 Highway signs.

6.1.5 PVC screens for monitoring petroleum hydrocarbons must have a slot width no less than 0.020 inches. Screens for all other applications must have a slot width no less than 0.010 inches.

6.1.6 Monitor wells must not be disinfected without prior written approval from the Department, except for monitor wells used for bacterial sampling.

6.1.7 In the event that contaminants are encountered during the drilling process, the water well contractor shall decontaminate the drilling rig and related apparatus to prevent the transfer of contaminants from the site.

6.1.8 Contaminated fluids and drill cuttings derived from drilling, developing, or sampling of monitor wells shall be properly containerized and disposed of by the water well contractor or other designated party.

6.1.9 The Department may require the elevations of the tops of monitoring and observation wells, excluding the caps, be established with reference to mean sea level datum or a common datum, as appropriate, to determine the direction of groundwater flow and related groundwater elevations to other available points. The surface used for this measurement must be permanently marked.

6.2 Flood Zone Wells

6.2.1 Standards set forth in this section are for wells in areas prone to wave action or flooding. These coastal areas are shown on Flood Insurance Rate Maps published by the Federal Emergency Management Agency and are designated as "A" or "V" zones.

6.2.2 Wells constructed in flood-prone or coastal areas shall be completed pursuant to subsection 5.11 .1.

6.2.3 Wells constructed on waterfront properties shall be constructed on the landward side of the property, unless otherwise approved by the Department.

6.2.4 Well construction beyond the Department's coastal building restriction line as defined in the Delaware Regulations Governing Beach Protection and the Use of Beaches is prohibited.

6.3 Public and Industrial Wells

6.3.1 The well owner shall be responsible for posting the Department well identification number on the exterior of the well enclosure.

6.3.2 All public wells for community water systems and all industrial wells must be logged by a qualified geophysical logging operator. The suite of logs shall include natural gamma, spontaneous potential, and resistivity. Other logs may be required by the Department.

6.3.3 Public wells shall be equipped with a backflow preventer, raw water sample tap, and a pump-to-waste valve on the discharge line of each well prior to the pre-storage isolation valve.

6.4 Heat Pump Recharge Wells

6.4.1 All water obtained from wells supplying a heat pump system shall be injected into the source aquifer.Where the requirements of subsections 6.4 .4 and 6.4.5 have been met, and the aquifer will not accept the water from the supply well, the Department may approve an alternate method at its discretion.

6.4.2 No heat pump recharge well may be constructed within 50 feet of any identifiable potential or existing source of contamination. Decommissioned septic systems are not a potential or existing source of contamination for heat pump recharge wells.

6.4.3 Other than thermal alteration, groundwater recharged to the aquifer shall be in its natural condition.

6.4.4 The diameter and screen length of all heat pump recharge wells shall be equal to or greater than the diameter and screen length of the heat pump supply well, unless otherwise approved by the Department.

6.4.5 Where a heat pump recharge well meets the requirements of subsection 6.4 .4 and the receiving aquifer will not readily accept the return flow, another well will be required.

6.5 Heat Pump Closed Loop and Direct Exchange (DX) Wells

6.5.1 No heat pump closed loop or direct exchange wells shall be constructed within 50 feet of any identifiable potential or existing source of contamination. Decommissioned septic systems are not a potential or existing source of a contamination for heat pump closed loop or direct exchange wells.

6.5.2 The solution contained in the heat pump closed loop well piping system shall be free of characteristic hazardous substances with the exception of ethanol-base antifreeze solutions designed for such systems. The use of non-toxic propylene-glycol-based antifreeze solutions is recommended.

6.5.3 Refrigerant prohibited by the Environmental Protection Agency shall not be used in direct exchange wells.

6.5.4 Prior to being connected to a manifold, the ends of the loop shall be temporarily sealed by fusion or capping. The use of tape is prohibited.

6.5.5 All buried pipe shall be marked with underground warning tape at a depth of 24 inches.

6.5.6 Pressure testing of the closed loop heat pump system network shall be conducted prior to putting the system into operation.

6.6 Miscellaneous Wells

6.6.1 Miscellaneous wells shall be subject to construction conditions as determined by the Department.

6.7 Agricultural Wells

6.7.1 Agricultural wells in an area for which a CPCN has been issued shall adhere to the following requirements:

6.7.1.1 The well is not permitted to be used for human consumption;

6.7.1.2 The well is not permitted at any time to be interconnected with any portion of any building's plumbing or any water utility's service connection. The well must be available at any reasonable time for inspection by personnel of the Department pursuant to subsection 1.2 .8 and the water utility serving the certificated area to ensure there are no interconnections.

6.7.2 The well permit shall be subject to revocation upon any violation of the above requirements and, upon revocation, the Secretary shall order that the well be sealed.

7 Del. Admin. Code § 7301-6.0

20 DE Reg. 180 (9/1/2016)<linebreak/> 20 DE Reg. 374 (11/1/2016) (Final)