Composting Success at Spotsylvania County, Virginia

Transcription

1 Composting Success at Spotsylvania County, Virginia Tim Jenkins Spotsylvania County Acknowlegements: Todd Williams, CH2M _WWGST_RRR_PPT_Template_01.pptx

2 Spotsylvania County, Virginia Population = 130, miles South of Washington, DC 50 miles North of Richmond _WWGST_RRR_PPT_Template_01.pptx

3 COMPOSTING FACILITY EXPANSION NEED Composted Dewatered Solids From Massaponax WWTP Only 240 tons/week (12,800 tons annually) Landfilled Solids From FMC WWTP 120 tons/week Old Compost Facility was Operating at Capacity Needed to Expand to Manage Solids Production Through 2025 Planned Capacity of 560 tons per week or 29,250 tons WWTP Solids per year _WWGST_RRR_PPT_Template_01.pptx

4 COMPOSTING FACILITY EXPANSION KEY DESIGN CRITERIA 18 DTPD (112.5 WTPD) capacity, 5 days per week 16%TS cake solids on average Ground yard waste primary bulking agent Mixing 4 hours per day, 5 days per week In-ground composting aeration system Continuous negative aeration during composting Odor control with maintenance redundancy Positive aeration during curing _WWGST_RRR_PPT_Template_01.pptx

5 SPOTSYLVANIA COMPOSTING PROCESS FLOW DIAGRAM BIOSOLIDS MIXING BULKING AGENT AIR COMPOSTING (21 days) ODOR CONTROL AIR SCREENING CURING (30 days) BULKING AGENT RECYCLING STORAGE (14-90 days) MARKETING/ UTILIZATION _WWGST_RRR_PPT_Template_01.pptx

6 Residuals Resource SPOTSYLVANIA Recovery COMPOSTING EXPANDED FACILITY Curing Odor Control Composting Screening Solids Receiving and Mixing Odor Control Bulking Agent Storage Control Building _WWGST_RRR_PPT_Template_01.pptx

7 BULKING AGENT STORAGE _WWGST_RRR_PPT_Template_01.pptx

8 MIXING WITH BATCH MIXERS Two 22 CY Mixers Weigh Scale Operation 30+ TPH Solids Capacity _WWGST_RRR_PPT_Template_01.pptx

9 PILE CONSTRUCTION Initial Mix Discharge Wood Chip Base Finished Compost Cover _WWGST_RRR_PPT_Template_01.pptx

10 Residuals Resource COMPOST Recovery AERATION SYSTEM Negative Aeration Only Eighteen 1500 CFM Aeration Stations 5,000 cfh/dry ton capacity Continuous Aeration with Temperature Feedback and VFD Fan Control _WWGST_RRR_PPT_Template_01.pptx

11 IN-FLOOR AERATION SYSTEM Below Ground HDPE Piping to Fans HDPE Risers with Flush Mounted Grates Engineered Patented Aeration Grate System 1872 Aeration Grates _WWGST_RRR_PPT_Template_01.pptx

12 BIOFILTRATION SYSTEM Biofilter Fans Humidification Odor Collection and Distribution Ductwork MCC Biofilter 60 Seconds Nominal Detention Time _WWGST_RRR_PPT_Template_01.pptx

13 BIOFILTRATION SYSTEM Four Fans, 27,000 CFM Each Aeration Lateral Compost Process Offgas Inlet Cooling Air Inlet Two Biofilters, 4 Cells Biofilter Media Screened, Sized Ground Wood _WWGST_RRR_PPT_Template_01.pptx

14 Odor Emissions W/O Biofiltration TOTAL = 8890 OU/Sec 6850 OU/Sec 2040 OU/Sec Composting Curing _WWGST_RRR_PPT_Template_01.pptx

15 Odor Emissions With Biofiltration TOTAL = 2905 OU/Sec 200 OU/Sec 2040 OU/Sec 97% Capture 6650 OU/Sec Composting 665 OU/Sec Curing 90% Removal Biofiltration _WWGST_RRR_PPT_Template_01.pptx

16 COMPOSTING FACILITY EXPANSION BIOFILTER ODOR SAMPLING RESULTS 4/26/2010 Dilution to Threshold (D/T) Detection Recognition Biofilter Inlet Biofilter Outlet Odor Removal % High Loading Rate Low Loading Rate _WWGST_RRR_PPT_Template_01.pptx

17 Positive Aerated Curing _WWGST_RRR_PPT_Template_01.pptx

18 COMPOSTING FACILITY EXPANSION ODOR MODELING RESULTS Modeling Confirmed Testing Results/Predictions Because No Offsite Impact, Enclosure not needed Air Handling and Biofilter Size is Less than 60% of that Required for a Totally Enclosed Facility Realized Savings of $3M in Capital Due To Smaller Biofilter Smaller Blowers and Ducting Lower Building Cost due to savings in Building Walls Building Insulation Corrosion Coatings Sprinkler System Realized 30% Reduction in Electricity Costs in O&M AND.Less Offsite Odor Impact Than If Enclosed Due to Limits of Biofilter Emission Concentration Smaller Footprint, Lower Biofilter Mass Emission Rate _WWGST_RRR_PPT_Template_01.pptx

19 PROCESS CONTROL 3 Wireless Temperature Probes/Pile Feedback to SCADA System to Control Blowers and Generate Operating and Regulatory Monitoring Records _WWGST_RRR_PPT_Template_01.pptx

20 _WWGST_RRR_PPT_Template_01.pptx Supervisory Control And Data Acquisition

21 SPOTSYLVANIA COUNTY COMPOST MARKETING Done Using In-House Staff Quality Product USCC STA Approved Registered as Fertilizer with Virginia Dept. of Agriculture Compost Produced is Widely Accepted Principal Users Are Landscapers, Soil Blenders, and General Public Principal Use is in Landscaping _WWGST_RRR_PPT_Template_01.pptx

22 Compost Sales are Strong, but Seasonal _WWGST_RRR_PPT_Template_01.pptx

23 SPOTSYLVANIA COUNTY COMPOST SALES VOLUME (CY) REVENUE 16% 4% 24% 5% 80% 71% Nursery Landscaping Residential _WWGST_RRR_PPT_Template_01.pptx

24 SPOTSYLVANIA COMPOSTING FACILITY CAPITAL COSTS Buildings/Facility/Engineering (2008) $15,500,000 Moving Stock (2007) $500,000 Original Facility Buildings/Improvements ( ) $1,000,000 Total $17,000, _WWGST_RRR_PPT_Template_01.pptx

25 SPOTSYLVANIA COMPOSTING ESTIMATED ECONOMICS at CAPACITY Capital Cost $17,000,000 Annual Depreciation $1,106,000 Projected Annual O&M $1,033,700 Subtotal $2,139,700 Projected Annual Compost Revenues $253,600 Total Annual Cost $1,886,100 Projected Annual Tonnage Processed 29,250 Cost Per Wet Ton Processed Annualized Capital $37.81 O&M $26.67 Total Cost per Ton Biosolids $64.48 Amortized at 4.5% Original Facilities - 20 year life; New Facilities - 30 year life Moving Stock - 8 year life _WWGST_RRR_PPT_Template_01.pptx

26 SPOTSYLVANIA COMPOSTING FACILITY 2012 O&M at 64% Loading Labor $283,400 Utilities (Electric) $83,600 Fuel $74,800 Maintenance $115,100 Miscellaneous $54,000 Subtotal $611,000 Biosolids Tonnage Processed 18,627 Cost Per Ton Biosolids Processed $41.00/ton Compost Revenues $215,300 Cost Per Ton Biosolids Processed After Product Sales $26.50/ton _WWGST_RRR_PPT_Template_01.pptx

27 SPOTSYLVANIA COMPOSTING FACILITY 2014 O&M at 78% Loading Labor $345,100 Utilities (Electric) $127,600 Fuel $77,100 Maintenance $152,900 Miscellaneous $50,000 Subtotal $752,700 Biosolids Tonnage Processed 18,627 Cost Per Ton Biosolids Processed $32.80/ton Compost Revenues $168,600 Cost Per Ton Biosolids Processed After Product Sales $25.50/ton _WWGST_RRR_PPT_Template_01.pptx

28 SPOTSYLVANIA COUNTY COMPOSTING FACILITY KEYS TO CONTINUED SUCCESS Commitment of leadership and staff to develop the facility and continue optimization No odor problems since facility started up in 2010 Successful product marketing program with USCC Seal of Testing Assurance Registration Compost Product is Excellent and Material is Sold Out Economics are very favorable to alternatives Award winning operation _WWGST_RRR_PPT_Template_01.pptx

29 Composting Success at Spotsylvania County, Virginia QUESTIONS? Doug Crooks _WWGST_RRR_PPT_Template_01.pptx