# COMAR Title 26 — Department of the Environment

## Subtitle 04 — Regulation of Water Supply, Sewage Disposal, Solid Waste, and Recyclable Materials

### Chapter 04 — Well Construction

#### Regulation .15 Construction Standards — Hydrogeologic Areas.

*COMAR 26.04.04.15*

A. Geologic and hydrologic conditions in Maryland require varying well construction standards. For the purposes of this chapter, the State has been divided into five hydrogeologic areas. A map of the approximate hydrogeologic area boundaries is in Regulation .39 of this chapter.

B. The Five Hydrogeologic  Areas.

  (1) Hydrogeologic Area 1. The area where the unconfined Quaternary aquifer of the Maryland Coastal Plain is of major importance; the area described in “United States Geological Survey (USGS) Professional Paper 822, Water Resources of the Delmarva Peninsula, 1973” and “Maryland Geological Survey (MGS), Report of Investigation No. 40, The Columbia Aquifer of the Eastern Shore of Maryland, Part 1 Hydrogeology, 1984”, which is incorporated by reference.

  (2) Hydrogeologic Area 2. The area where the confined aquifers of the Maryland Coastal Plain are of major importance as described in “MGS, Open File Report 72-02-1, A User's Guide for the Artesian Aquifers of the Maryland Coastal Plain, 1972”.

  (3) Hydrogeologic Area 3. The rocks of the Maryland Piedmont and Blue Ridge as described in “MGS, Report of Investigation 10, Ground Water Occurrence in the Maryland Piedmont, 1969”, and “MGS, Open File Report 69-02-1, Ground Water Aquifers and Mineral Commodities of Maryland, 1969”, exclusive of the carbonate rocks.

  (4) Hydrogeologic Area 4. The sedimentary rocks of the Maryland Appalachian Highlands and Valley and Ridge Provinces, exclusive of carbonate rocks, as described in the references listed in Hydrogeologic Area 3.

  (5) Hydrogeologic Area 5. The carbonate rocks as defined by the “Maryland Geological Survey, Geologic Map of Maryland”, Scale: 1:250,000 dated 1968.