SR0084773_SSNL - Laserfiche WebLink

Home Browse Search

V. CONCLUSIONS Although the depth to groundwater is approximately 70 ft b.g.s., the filter bed should be as high in elevation as possible. The influent line should come through, or at the bottom of the building footing, if possible. The additional two seepage pits connected to the filter bed will provide an additional 420 sf of infiltration area in combination with the 928 sf filter bed. Under worst-case scenario saturated soil conditions, these OWTS structures (filter bed and two seepage pits) can manage: 928 + 210 + 210 = 1,348 sf x 0.570 gals/sfday (Average Acceptance Rate) = 768 gpd of effluent. Anticipated daily effluent flow volumes calculated for design purposes is 175 gpd. As the primary disposal area matures with biomat formation, the seepage pits will ultimately manage a smaller percentage of the effluent flows, while the filter bed manages the remaining percentage, thus keeping the majority of the effluent volume as high in elevation as possible within the soil environment. It is imperative that the septic tank and filter bed/seepage pits are barricaded so that they cannot be driven over, parked upon, or anything stored on these structures. Barricades can be curbs, railroad ties, bollards or any other restrictive method. The septic tanks should be pumped every three to four years to increase disposal area longevity and mitigate nitrogen loading. No food byproducts should not be flushed down the break room sinks. Additionally, there should be regular effluent filter maintenance by a pumper service at the time of pump-out, if not sooner. Chemical cleaners must be used sparingly since these cleaners may disrupt septic tank biology. Nitrate loading from this project may be considered inconsequential due to the Parcel size of 40.36 acres, and was determined to be 0.61 mg/L nitrate-nitrogen. The soil types encountered during the drilling procedures, primarily silts and clays, will provide attenuation of nitrate loading from the proposed OWTS design of taking advantage of the shallow soil mitigation of nitrification and denitrification properties. It is important to recognize that all septic systems and disposal areas have a lifespan. A definitive lifespan is unpredictable due to the numerous operational and environmental factors involved. However, due to the design considerations (i.e., the two seepage pits), lifespan is anticipated to be very long. - Page - Chesney Consulting