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III. NITRATE LOADING STUDY FINDINGS <br /> A. WASTEWATER FLOW VOLUME PROJECTIONS AND <br /> CHARACTERISTICS <br /> Wastewater Flow Volume Projections <br /> To determine nitrate-nitrogen loading from any project, wastewater flow volumes must be <br /> determined as accurately as possible. Flow volume projections will be approximated from the <br /> potential number of on-site truck drivers/employees/customers, as illustrated in Table 3. It is my <br /> understanding that the proposed restroom this will be the only domestic wastewater fixture units <br /> for this project. According to EHD standards, people who are associated with a facility, whether <br /> they are employees are not, must have'access to available restroom facilities. <br /> The following chart illustrates the Employees/Customers/Deliveries, etc. per work shift used to <br /> calculate the anticipated wastewater flow volumes. <br /> TABLE 3 <br /> Number of Employees Customers per Shift Vehicles per Shift <br /> 4 8 31 <br /> Taking a reasonable usage factor of five gallons per day(2.5 gals AM, 2.5 gals PM) for each class <br /> of on-site people, including drivers even though they are long-haul and will not be on-site daily, we <br /> find the following: <br /> Total usage=43 on-site people x 5 gpd/person=215 gpd x 6 days per week= <br /> 1,290 gpw x 50 wks/yr=64,500 gpy. <br /> Wastewater Characteristics <br /> Blackwater will originate from toilets and graywater from hand washing. Additional wastewater <br /> constituents may consist of other liquids to the system, such as coffee,juices, etc. Industrial or <br /> commercial chemicals, solvents, etc. must not be introduced into the wastewater treatment system. <br /> The scientific literature cites nitrogen concentrations in domestic septic effluent typically ranging <br /> from 17 mg N/L for graywater basins, sinks, etc. to 140 mg N/L for blackwater toilet wastes. <br /> Therefore, considering a 38/52 percent usage for toilet and hand wash water volume, respectively, <br /> a value of 62 mg N/L (38%of 140 mg N/L plus 52%of 17 mg N/L) from the septic effluent will be <br /> used to calculate nitrate-nitrogen loading for this project(see Kaplan-septic Systems Handbook,Pg. 147). <br /> B. CALCULATED NITRATE-NITROGEN LOADING <br /> NLS§3.4,3.5,3.6. The calculated nitrate-nitrogen impact to the soil and ultimately to the <br /> groundwater is difficult to determine due to the large number of variables involved and variables <br /> unknown at this time. These include: 1.) Impact from upgradient nitrate sources, <br /> 5 <br /> Chesney Consulting <br />