SU0006677 SSNL - Laserfiche WebLink

Home Browse Search

rr4. . Published Data in the San Joaquin County Sewage Standards and scientific literature. . Number of bathroom fixtures correlated with bathroom use per capita for a facility. . Number of parking spaces for a facility. Maximum number of people(e.g., employees, customers,etc.)for a facility. . Historical wastewater flow data from an existing facility. 1. The San Joaquin County Sewage Standards assigns l5lag lons per person for Industrial Buildings with no food cafeteria, or 30 ga11Qgs mer person for day wRrkcrs at offices. __. 2. The Sewage Standards assign 150 gallons per toilet fixture for employee/public use. Since it cannot be adequately determined how many people will use the Office Trailer restroom on a daily basis, the Sewage Standard of assigning 150 gallons per day is applicable. However, this Standard was based on old style toilets using 3 to 5 gallons per flush. Contemporary toilets use 1.5 gallons per flush. Wastewater flows projected from the Office Trailer is equivalent to 100 flushes per day(150 gals/day 1.5 gals/flush/day= 100 flushes)which incorporates an enormous safety factor. Wastewater Flow Characteristics It is assumed there will be no cooking, or food production in the Office Trailer. Therefore, there should be no concentrated organic loading. The characteristics of the wastewater flow will be predominately blackwater from toilets, with a comparatively small volume of graywater from sinks, or other sources of graywater. Additional wastewater constituents may consist of coffee,juices or other similar type liquids to the system. No industrial or commercial chemicals, solvents, etc. are to be introduced into the septic system. From the anticipated wastewater characteristics described above, 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 a dilution effect that graywater from showers, laundry, and dishwashing would provide from a household. 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 ind sinkOvate yr olume,respectively, a value of 103 mg N/L of septic effluent will be used to calculate nitrate-nitrogen loading for this project. A value of 66 mg N/L is typically used for residential calculations, as indicated in the scientific literature. B. CALCULATED NITRATE-NITROGEN LOADING The calculated nitrate-nitrogen impact to the soil and ultimately to the groundwater is difficult to determine due to the large number of variables involved, and variables unknown at this time. These include: 1.) Impact from upgradient nitrate sources, 2.) Variability in wastewater flows, nitrogen concentrations and dilution effects from effluent and stormwater recharge, 3.) Changes in groundwater directional flow and elevation, 4.) Denitrification potential within the soil environment and within the confined and unconfined aquifers and 5.)Potential landscape uptake of nitrogen. 7 Chesney Consulting