7 Del. Admin. Code § 7103-75.0

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

Section 7103-75.0 - Surface Drainage and Runoff Control

75.1 Drainage of storm runoff shall be considered in design. Spray fields must be protected against flooding, ponding and erosion. Runoff shall be channelized through or around the wastewater irrigation site. However, the collection and channelization of irrigated wastewater must be avoided. Direct application of wastewater to drainage ditches and seasonal watercourses is prohibited.

75.2 A properly designed and operated slow rate land treatment system will not produce direct runoff; i.e., all water applied will infiltrate into the soil profile. Thus, irrigation on frozen soils must not be practiced. Sites that experience direct runoff as a result of wastewater irrigation will be required to reduce hydraulic loading rates. Tailwater return systems may be required as a remedial action. Indirect runoff as a result of interflow, changes in slope, and shallow restrictive soil layers can be expected at some slow rate land treatment sites. Indirect runoff is acceptable when it is dispersed over a wide area. However, monitoring of streams affected by such indirect runoff shall be addressed in the Plan for Operations and Management.