7 Del. Admin. Code § 7103-76.0

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

Section 7103-76.0 - Subsurface Drainage

76.1 General

76.1.1 Sites with a seasonal high water table less than 5 feet in depth, including groundwater mounding as a result of wastewater irrigation, may require drainage improvements to assure a desired zone of aeration for optimum wastewater treatment and plant growth. A minimum 2-foot depth for this zone shall be maintained at all times.

76.1.2 The Department recommends Section 16 of the USDA Soil Conservation Service National Engineering Handbook" and the 1983 publication Land Drainage" by Smedema and Rycroft as references for the design of drainage systems. In addition, the Soil Conservation Service in Dover, Delaware has available the DRAINMOD" computer program (Skaggs,)

76.1.3 ¹Name and address for domestic wells, all available information for all other wells. Well types are as defined in State of Delaware Regulations Governing the Construction of Water Wells. Information may be obtained (for a fee(c)) from Delaware Water User Data System (DWUDS) through the Department.

76.1.4 1980; Skaggs and Nassehzadeh-Tabrizi,1982). This is a comprehensive drainage design model for agricultural and wastewater irrigation systems.

76.2 Effluent Limits and Monitoring

76.2.1 Discharges from drainage systems for wastewater irrigation facilities fall under point source discharge rules and regulations that require a National Pollutant Discharge Elimination System (NPDES) Permit. The required quality of the discharge from the drainage system is dependent upon the receiving stream and will be determined on a case-by-case basis. Water quality monitoring of the drainage system discharges will be in accordance with NPDES permit requirements.

7 Del. Admin. Code § 7103-76.0