Laserfiche WebLink
( <br />( <br />- 12-2/*" layer of sand placed over the natural roughened topsoil <br />is fed efHuent from a pressure distribution system in an <br />overlying rock bed, <br />- Biomat "valve" forms at the rock/sand interface which is 12-2/» <br />above the natural soil. <br />r Because of the pressure distribution, an unsaturated air/effluent <br />contact is maintained as treatment occurs in the sand bed. <br />- Treated effluent dispenses into the topsoil, moving vertically <br />and laterally underground until it seeps away or evaporates, <br />c. Public Acceptance <br />- Pressure distribution requires use of a pump, hence owner main­ <br />tenance required} however, with well—designed and installed <br />pump stations, vei^ few problems occur. <br />- The concept of a "mound" or a hill in the back yard creates some <br />homeowner resistance, but mounds are actually easy to disguise, <br />- To the uninitiated, seepage out the toe of the mound would seem <br />likely; this has not occurred in the 13 mounds in Orono, and <br />shouldn't occur in a properly designed and constructed mound. <br />- Five vears ago, sewer contractors "pshawed" the idea of using <br />mcunds in this area. Today, most contractors consider them <br />as a fairly standard practice, <br />d. Quality Control <br />- Standardizedr'design <br />- System design and site planning geared to each specific site <br />- Installer training and licensing <br />- Standardized site evaluation is a problem since each site evaluator <br />or engineer has his ovm ideas on test methods and interpretations, <br />- Perc rate upper boundary for mounds is somewhat speculative. <br />e. Miscellaneous points <br />- Cost to homeowner; standard system Ctrenches) $25CC-3500 <br />mound system w/pump,etc, $/*CCC—fCCO <br />- Because of higher cost, repairs using mound systems i.re rare, <br />even where they probably have a better chance of working. <br />f