Agenda - 05-21-1985 - Laserfiche WebLink

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D. Need for Proposed Facilities and Actions (The purpose of this project Is to provide the most cost effective site/ method of sludge disposal for the Mason Farm wastewater treatment plant. Sludge from the plant is presently being disposed by spreading on nine privately owned agricultural sites totalling 443 acres in southwestern Orange and northern Chatham County. 11rivately owned application sites are not always available because of inclement weather, crop harvesting, crop growing, and grazing schedules. Because of these limitations, OWASA needs to develop the capability to manage and dispose -of sludge during periods when it is not desirable or 'there are conflicts with the land- owner's use of the site. The purchase of the proposed 59.95 acre site would give OWASA the capability to dispose of sludge in an orderly manner. At present plant .loading conditions, there have been periods extending for 30 to 45 days when the privately-owned sites have been unavailable for sludge disposal-) Plant sludge has been managed on-site for the most part by temporary storage in the Mason Farm wastewater treatment plant digesters. During the more extended periods when the digesters have been filled to capacity, sludge has been held in the aeration process-by increasing the mixed liquor solids concentration. This temporary sludge holding arrangement has the potential to cause plant process upsets and needs to be avoided whenever postible. If no action is taken to correct this situation, it is anticipated that plant process upsets will result from the shortage of adequate facilities to provide for ultimate sludge dispos*al.• These process upsets could result in the discharge of inadequately treated wastewater to Morgan Creek. The existing severed population for the OUIASA service area is 44,500 and the projected sewered population for the 20 year planning period is 63,750. Current sludge production is 1 160,000 pounds of dry solids per for the planning period year, and the projected level of sludge production is 1,690,000 pounds per year. ge capacity for the• proposed site at a flow of 5.5 mgd The current storage is approximately 57 days and the* storage capacit y at the design of 8.0 mgd is 40 days. E. Alternatives Analysis - The 201 facilities plan and amendment considered several alternativese The evaluation of these alternatives* can be grouped into two categories: (1) alternatives considered but not selected for detailed evaluation, and (2) alternatives selected- for a more detailed evaluation. Alternatives considered but not selected for detailed evaluation. ae Sludge incineration - This approach was considerid a volume reduction technique and ultimate disposal would still be required. As a result of potentially increasing cost to operate an incineration process and the high energy cost requirements, this is not a viable alternative • since a successful operation would be dependent upon the capability to recover or.reclaim energy from the process. -4-