Del. Code tit. 16 § 1506
All plans for the construction or alteration of a water supply system shall be submitted to the Division of Public Health of the Department of Health and Social Services for approval before the construction or alteration of said water supply system begins. Notwithstanding the exclusions in § 1501(b) of this title, the Division of Public Health may review and inspect the construction of wells, dams, reservoirs, surface water intakes and waterway obstructions for health aspects, including but not limited to such features as venting, grouting, integrity of well seals and protection from contamination. Any negative health aspects observed by the Division of Public Health during such review or inspection shall be referred to the Department of Natural Resources and Environmental Control for investigation, resolution or enforcement action. In addition, and pursuant to § 7931 of Title 16, a dug well or any type of private water supply that is located where there is access to a public water supply shall not be permitted unless the private water supply is approved in writing by the Department of Health and Social Services.
16 Del. C. § 1506