SU0002274 - Laserfiche WebLink

Home Browse Search

AUG- 9-99 MON 8: 16 AM 7-H TEI�IHNICAL SVC GRP FAX N0, 53027322190 P. 4 area in San Jouquin County. Rightly so, the San Joaquin County Department of Environmental Health is greatly concerned with any elevation of that number. A previous report on this development back in 1990, by others, determined that waste discharge via septic tank effluent would not elevate the NO3 levels in the ground water beyond 45 mg/l. We disagree with that finding. It appears that the finding was based on unit flows of only 150 gallons per day per connection rather than the correct assignment of 3 50 gallons per day per connection. In addition there are some other elements of the equation that were not previously considered such as the co-efficient number for storm run off when applying the rainfall values. When applying the Hantzche-Finnemore Equation to the numbers presented in this proposal, the resulting predicted elevation of nitrate nitrogen in groundwater is 21 mg/l or 90 mg/l as NO3. With the nitrate nitrogen limitation of 10 mg/l or 45 mg/1 as NO3 it is apparent that some form of nitrogen reduction is required of any effluent prior to discharge. Further the method of nitrogen reduction should be a"controlled" method regulated by proper continued operation of the facility process. Wastewater Treatment Plants: The selection of a treatment plant and process for this project must, at a minimum, described above, meet certain criteria. 7-H has selected a Variable Depth Reactor tm, Secondary Wastewater Treatment Plant for this project. The Variable Depth Reactor tm, meets all the minimum criteria listed below. 1. The process must, at a minimum, meet the Secondary Treatment requirements as set forth by the United States Environmental Protection Agency. Which means that the plant effluent quality must have a thirty(30)day average BOD concentration of 30mgA and a total suspended solids concentration of 30 mg/l. Concentrations may be required to be more strict depending on the point of discharge and/or the application of water reuse, (reclaimed water). 2. Most importantly, the process must have the capability of reducing"total nitrogen"down to a level that will preclude the elevation of nitrate nitrogen in the local groundwater to 10 mg/l or NO3 of 45 mg/l, inclusive of the present 30 mg/1 of NO3 presently in the groundwater_ 3. In addition to the reduction of BOD and total suspended solids listed above, the total process must be capable of treating and stabilizing the raw sewage solids and the biological solids produced in the treatment process. The solids stabilization system must be offensive odor free. 4. The secondary biological process shall be efficient to meet the requirements, have day to day operational dependability and simple to operate. 5. The treatment plants shall be skid mounted and ninety(90)per cent assembled when shipped. The plants shall be upright, out of the ground installations_ The plants shall have the capability of being set permanently on a concrete pad. 6. The plants shall each be equipped with a computerized control panel that automates the basic functions of the facility such as valve opening and closing, 3