SU0011908 SSNL - Laserfiche WebLink

Home Browse Search

IV, SEPTIC SYSTEM DESIGN, OPERATIONAL CRITERIA, AND NITRATE-NITROGEN IMPACT MITIGATION A. Septic System Operation The new septic system for the proposed restroom facility has been designed for 150 gpd. This Average Daily Flow (ADF) is based on an unlikely,but possible, maximum of five employees I (owner, secretary, salesman and two mechanic), and five customers per day. Typically, EHD uses a number of criteria to project wastewater flow volumes based upon 1.) Published data (e.g., IS gals/employee-eustomer/day), 2.) The number of bathroom fixtures or bedrooms, andfor 3.) The number of parking stalls. it is our understanding that tere At be clic bathroom in the office and gne.sink. Considering that if the toilet (1.5 gallon/flush) was flushed every one-quarter hours over the an eight hour work day, we have: 4 flushes/hr x 8 hrs x 1.5 1 gals/flush x 1 toilet= 48 gallons, which leaves approximately 100 gallons for additional use. Therefore, this is a plausible ADF water usage. The primary filter bed, and ultimately the 100%replacement area tiller bed will consist of Standard Infiltrator Chambers(Ks SC (Shallow Cover). Six inch spacers between chambers with the effluent trickling into the"front" of the chambers from_a seven port distribution box. l cover er soil hover the car the chs must consistpfu.sancl} Igctrn mu!<;righy)i[h [QUC as'ix inchce�oi ambers. A grass-type plant should be planted over the disposal area 11 so that the plant roots can evapotranspire effluent during favorable times of the year. B. Wastewater Disposal System Design Specifications Septic Tanks Influent from the office will gravity Ilow into a 1,200 gallon,septic tank that does not need to be traffic rated since it will be inside a gated area, and therefore cannot be drivsn cr. A filter, (c.g.. ZAibel or Orenco) must be installed in the second compartment. Effluent from this tank will level } gravity to a seven-outlet distribtttjoahax.(Zabel PartNo: G- DS DB 7L). Effluent from this distribution box NN ill clow equally into six Infiltrator Chambers. This primary tank will provide preliminary treatment and trap paper, etc. The tank must be pumped on a prescribed interval basis J t observations of paper and scum accumulation; e.g., every six months to every depending on direc three years, depending on sludge/scum accumulation. Los ors for users on septic tanks vary withusage during the hour ofthe day, and Jay ol'thc hourly rates are associated with normal working hotus. The ratio of the peak day to ay can vary from 1.5 to >5, depending upon the usage. However, peaking factors arc nt since the effluent pump will dose on demand. A peaking factor of 2.5 (average d 5) will be used in the calculation below: Page -6- _ — CGesney Cnnsnitiir�,