10 ENVIRONMENTAL STANDARDS >> 10.300 Additional Resouce Standards >> 10.380 Water Resource Protection Areas (WRPA)

SECTION 40.10.380     WATER RESOURCE PROTECTION AREA (WRPA)

  1. Water resource protection areas are the Cockeysville Formation, Cockeysville Formation Drainage Area, wellheads, and recharge areas. All such areas are as depicted on the three (3) map series "Water Resource Protections Areas for the City of Newark, City of Wilmington, New Castle County, Delaware," prepared by the Water Resources Agency for New Castle County that is dated 1993, or as amended. These areas shall be protected as required by the following sections to protect the County's water resources from contamination and pollution and to insure adequate water quantity for future needs.
  2. No development shall be permitted to have more than twenty (20) percent impervious surface ratio unless an environmental impact assessment report certified by a State-registered professional geologist or professional engineer with a background in hydrogeology indicates that additional development would not endanger the public or the environment. All environmental impact assessment reports performed pursuant to this Section shall be reviewed in accordance with Section 40.10.385 and the procedures set forth in Article 30 and Article 31 for environmental impact assessment reports. The impervious surface ratio and open space ratio operate independently and are based on the base site area.
  3. The Department may permit the expansion of existing nonconforming sites within Water Resource Protection Areas, which exceed the twenty (20) percent impervious cover standard, provided the proposed expansion of the site will reduce the existing impervious cover by a minimum of five (5) percent for sites of two (2) acres or less, a minimum of ten (10) percent for sites greater than two (2) acres and less than five (5) acres, and a minimum of twenty (20) percent for sites greater than five (5) acres and larger.
  4. The Department may consider the contribution of like land by the applicant to be preserved in other Water Resource Protection Areas. A conservation easement or the outright acquisition of the like land or resource shall occur which will prohibit the disturbance of the like land in perpetuity. Like lands are those lands within a Recharge or Wellhead WRPA that have infiltration rates that are equal to or greater than those found on the subject property. The minimum area of the restricted land shall be the area that would otherwise be required by this Chapter.

(Amended September 22, 1998 by Ordinance 98-080; amended December 14, 1999 by Ordinance 99-075; amended September 26, 2006 by Ordinance 06-060; amended November 10, 2009 by Ordinance 09-068)

SECTION 40.10.381     COCKEYSVILLE FORMATION

Special on-site investigation as required by Section 40.22.110.

  1. The County shall require a subsurface investigation report on the stability of the rock formation and likely contamination risks.
  2. In addition, surface drainage shall be designed to prevent infiltration that could lead to increased erosion of supporting rock. The County may require lined channels or stormwater pipes that decrease the level of infiltration to the groundwater.
  3. In determining whether development may be permitted beyond the twenty (20) percent impervious surface ratio limitation of this Division, the contribution of like land by the applicant to be preserved in the Cockeysville Formation shall be considered as a factor in the environmental study and report.

SECTION 40.10.382     RESERVED.

(Amended December 14, 1999 by Ordinance 99-075)

SECTION 40.10.383     WELLHEAD PROTECTION AREAS (PUBLIC WATER SUPPLY WELLS)

  1. Wellhead protection areas.
    1. Type A wellhead areas shall be one hundred (100) percent open space within three hundred (300) feet of the wellhead. Within that area, impervious surface shall be limited to building and access associated with the well and distribution and treatment facilities and their maintenance. In the case where the three hundred (300) foot required open space cannot be attained on the same lot as the wellhead, a conservation easement on one or more adjacent lots shall be necessary.
    2. Type B and C wellhead areas shall be limited to twenty (20) percent impervious surface ratio within three hundred (300) feet of the wellhead.
  2. The resource protection area around a public water supply well which draws from a confined aquifer as interpreted by the Delaware Geological Survey (DGS), DNREC, or a State-registered professional geologist with approval by DGS and DNREC shall be one hundred and fifty (150) feet. The protection area around a well not interpreted as drawing from a confined aquifer may be reduced below three hundred (300) feet where an environmental impact assessment report is approved demonstrating that a minimum sixty (60) day time of travel from a potential contaminant to the public water supply well is maintained. In no case shall the protection area for unconfined aquifers be less than one hundred fifty (150) feet. The assessment reports shall be based on an on-site hydrogeologic study.

    Notwithstanding any other provisions in Chapter 40 of the New Castle County Code, the minimum lot area required for a public water supply well and related facility drawing from a confined aquifer shall be one (1) acre; and, the minimum lot area required for a public water supply well and related facility drawing from an unconfined aquifer shall be two (2) acres. In the case where the minimum lot area cannot be met, because the public water supply well and related facility is proposed on an existing lot less than the minimum required, and where the total wellhead protection area required is not wholly owned by the public water utility, a conservation easement on one or more adjacent properties shall be necessary to satisfy the appropriate public water supply well minimum wellhead protection areas. The terms of the conservation easement shall prohibit any activity detrimental to the public water supply well. The owner of the public water supply well shall be responsible for monitoring the property pursuant to the terms of the easement.
  3. The natural runoff flowing into wellhead areas shall be allowed and all new stormwater runoff shall be diverted around the wellhead protection areas wherever practical.
  4. A stormwater system's discharge to wellhead WRPA's shall be by sheet flow through a grassland or discharged from a stormwater management facility having a wetland or aquatic bench. Stormwater runoff from all parking areas shall be directed to a stormwater management facility before it is discharged into a wellhead WRPA.
  5. The replacement of any existing public water supply well that was not required to meet this wellhead protection requirement at the date of its original installation and that has failed, shall be exempt from meeting this wellhead protection requirement.

(Amended September 22, 1998 by Ordinance 98-080; amended December 14, 1999 by Ordinance 99-075; amended Novmeber 10, 2009 by Ordinance 09-068)

SECTION 40.10.384     RECHARGE AREAS AND COCKEYSVILLE FORMATION DRAINAGE AREAS

  1. When impervious cover is proposed by the applicant at a rate greater than twenty (20) percent of the site, the applicant shall be required to demonstrate that the quality of storm water runoff is equal to or greater than predevelopment conditions and the quantity of stormwater runoff is equal to or less than predevelopment conditions.
  2. Those areas of open space not currently forested, shall have a minimum of twenty-five (25) percent of their area reforested pursuant to Section 40.10.351 . The Department may reduce this requirement where the applicant prepares an Environmental Impact Assessment Report demonstrating to the satisfaction of the Department that reforestation will result in more than a twenty (20) percent loss in groundwater recharge due to the soils and hydrogeologic conditions of the site. The report shall include an annual water budget compiled on a month by month basis comparing existing and post-development mature forest conditions. Applicants shall submit information regarding the types of trees evaluated, soil conditions (including percolation rates), pH types, assumptions regarding rainfall events, and topography. The report shall also include a water quality analysis comparing the water quality benefits of mature forest cover to the proposed alternative ground cover.

(Amended September 22, 1998 by Ordinance 98-080; amended December 14, 1999 by Ordinance 99-075)