Fort Walton Beach Council agenda — 06-09-09 regular — reading text

when this process is followed by secondary clarification. The two biological treatment basins are configured with influent entering an anoxic zone to provide both anoxic selector and denitrification when combined with the nitrate rich internal recycle ( NRCY) from the aeration zone. The effluent from the anoxic zone flows into the aeration zone for biological treatment and oxidation of the influent CBOD and ammonia. Mixed liquor suspended solids (MLSS) flow from the aerobic zone to a second anoxic /aerobic process where further reduction in the levels of CBOD, nitrate, and nitrite occur before the MLSS flows to the two secondary clarifiers. The secondary clarifiers provide liquid -solids separation and are designed based on USEPA Class 1 Reliability Requirements. The RAS pumping system is provided to return MLSS that have settled in the secondary clarifiers to the activated sludge biological treatment basins before the first anoxic zone. The WAS pumping system is provided to remove a portion of the MLSS from the secondary clarifiers to the solids digestion process. Figure F1 is a process diagram of the facility. Effluent Management Effluent management includes UV disinfection and effluent pumping and an in -plant reclaimed water system for process operations and landscape irrigation. The effluent management structure includes the new UV light disinfection system, as well as the pumping wet well for the effluent and in -plant water pumps. The structure has equipped to handle the current average daily and peak flow of 10 mgd and 25 mgd respectively; but has been designed and constructed to accommodate additional equipment to meet the future average daily and peak hourly flows of 15 mgd and 37.5 mgd. The new UV disinfection system equipment shall disinfect the clarifier effluent to the limits prescribed in the permit. The UV system shall implement low pressure high intensity lamps arranged in open channels where the water shall flow by gravity continuously. The new effluent pumps consist of three vertical turbine pumps designed to pump the peak hourly flow of 25 mgd to the new RIBs.  V f 2E L6 CL 0 LA CL Z{ 0LL CL k k 3 o / roc \ fc k t a G 2 o Ems LL kk G\ « 3 LL DD Z / Rw s z 2 eƒ kia IL j66`§ # I 2 z Eoj( i$t 2 G- k5 60 k§ oo 000, N% 22 C LuUl @krR 0) n 8 0 W2 \\ as u z k LU§ §) @ (®( \§ uj LU ew k& z< So § u! zuuzu i 223e « §aU %kUk L)0 LU UU)( Lcc .§ /§ A2 ca k1 dg E IL J  APPENDIX E ARBENNIE PRITCHETT WRF Biosolids Management Biosolids management facilities are intended to prepare the sludge for land disposal. The processes include sludge thickening, aerated sludge digestion, sludge dewatering, and dewatered sludge loading for offsite disposal. A rotary drum thickener and polymer addition system is provided to thicken the WAS to a concentration of about 5 percent before it is discharged into the digester. Two pre- stressed concrete aerobic digester tanks are provided to treat the biosolids to meet the Class B standards for land application. The digested sludge is conveyed to a centrifuge for dewatering to a concentration of greater than 18 percent. Polymer is applied to enhance the dewatering process. The dewatered sludge shall be discharged from the centrifuge directly to tractor trailers or storage bins for transport to the land application site. The biosolids management unit processes are designed based on the average daily flow of 10 mgd and the assumption that the sludge dewatering units will operate seven hours per day, five days per week. Support Facilities Support facilities include a new administration /laboratory building, maintenance building, and other ancillary electrical buildings and facilities, including two 1 mega -watt standby diesel generators design to power the plant operations during extended power outages. Figure F2 provides a site layout of the facility. Rapid Infiltration Basins The effluent disposal phase of the project involves the conversion of a portion of the existing 650 -acre sprayfield into a 200 -acre rapid infiltration basin system. The new RIB system consists of 18 individual RIBs and is designed to meet the peak flow of 25 mgd. Effluent from the WRF is pumped to the RIBs through 2 -30 -inch diameter mains; and the system is designed to operate up to two RIBs at peak flow. Figure F3 provides a layout of the RIBs. Project Status Construction of the new WRF is approximately 90% complete and the construction of the RIBs is 100% complete. Construction of the WRF is expected to be complete by the end of September of 2009. 0 g F i33JJn 55`' 0 tm1pp p mm4 V 2W Z d JY 1 q -3Mi, 9 o a h y b s i