SU0004912_SSNL - Laserfiche WebLink

Home Browse Search

III. NITRATE LOADING STUDY RESULTS A. WASTEWATER FLOW CALCULATIONS AND CHARACTERISTICS To adequately determine nitrate-nitrogen loading from the proposed project, wastewater flows must be defined as accurately as possible. Flow determinations are based on information supplied by Mr. Mike Kniss, and the number of parking stalls on the site plans: EMPLOYEE OFF-SEASON PEAK-SEASON (November-January) (February- October) Office I Employee: 8:00 A.M.to 5:00 P.M. Possible 2 Office Employees 8:00 A.M.to Monday through Friday 5:00 P.M. Monday through Saturday Mechanics 1 Mechanic: 8 hrs per day-5 days/wk Possible 2 Mechanics: 8 hrs per day-5 days/wk Other Employees/ 4 Employees,for a total of 6. Total Total parking stalls= 12 for total number of Customers parking stalls= 12 potential people on-site. There will be no cooking within a kitchen or office area and therefore, no need for a garbage disposal. Consequently,there should be no highly concentrated organic loading. The characteristics of the wastewater flow will be predominately blackwater from toilets, with a comparatively small volume of graywater from sinks and no showers. Other wastewater constituents may consist of coffee,juices or other similar type liquids to the system. B. CALCULATED IMPACT FROM NITRATE-NITROGEN LOADING From the anticipated wastewater characteristics described, the nitrogen emanating from the project may be at a higher concentration than what would normally be found in a typical domestic or household system. This can be attributed to the lack of the dilution effect that graywater from showers, laundry, etc. would provide. The scientific literature cites nitrogen concentrations in residential septic effluent typically ranging from 17 mg N/L for basins, sinks, etc. to 140 mg N/L for toilet wastes. Therefore, considering a 70/30 percent usage for toilet water volume and sink water volume, respectively, a value of 103 mg N/L of septic effluent will be used to calculate nitrate-nitrogen loading for this project. The loading projection is based on the maximum number of employees who may potentially use the toilet/sink, etc. on a daily basis, which incorporates an acceptable safety factor as illustrated below: 6 people anticipated, 8 hrs/day, 5 days/wk. Parking for 12 people, incorporates safety factor of 2. Each person is assigned 15 gallons per day (San Joaquin County Sewage Standards for Industrial Buildings with no cafeteria): 12 people X 15 gals/person/day= 180 gals/day X 3.79 L/gal=682 L/day X 103 mg N/L= 70 grams N/day X 260 days/yr(5 days/wk-52 wks/yr)= 18 kg N/yr X 2.2 Ib/kg= 40 lbs N/yr 5 Naffey Ag Research