Design of Elevated Sand Mound Disposal System

Design of Elevated Sand Mound Disposal System. 1. These guidelines present requisite site characteristics, design criteria, and construction techniques for on-site mound sewage systems. These guidelines provide a systematic approach to mound system design for typical domestic household wastewater. For systems serving other than single family dwellings the designer is cautioned that simple extrapolation of this information may not be appropriate. 2. When addressing wastewater flows that differ from a septic tank, such as those characterized by high biological oxygen demand (BOD5), total suspended solids (TSS), or oil and grease, the elevated sand-mound has inherent limitations. Wastewater from non-domestic sources should be evaluated on a case-by-case basis, to determine the amount of pretreatment necessary to apply to an elevated sand mound. The wastewater applied to an elevated sand mound should not exceed 220 mg/l BOD5 or 145 mg/l TSS (no TSS particles should be retained on a 1/8th inch screen). 3. Mounds are an excellent treatment and disposal choice on appropriate sites, but they are not very forgiving. Special attention must be given to siting, design, pre-construction planning, site preparation, filter media selection, construction and maintenance of these systems. Quality control throughout the process cannot be overemphasized.