Biosolids Management and Disposal Trends
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Final Long-Range Biosolids Management Plan Job No. J-40-7 Prepared for Orange County Sanitation District December 2003 Prepared by 3 uttonH Centre Drive, Suite 200 Santa Ana, California 92707 In Association with CDM Tetra Tech, Inc. W052003003SCO TITLEPAGE-CONTENTS.DOC/ 033370021 Contents Executive Summary Project Summary Technical Memorandum 1 – Review of Existing District Documentation and Regulatory Outlook Technical Memorandum 2 – Viable Biosolids Product Markets Technical Memorandum 3 – Implementation Plan for Sustainable Product Markets Technical Memorandum 4 – Ranking Market Alternatives Technical Memorandum 5 – Viable Product Technologies Technical Memorandum 6 – Cost Evaluation Model Technical Memorandum 7 – Implementation Schedule and CIP Outline Technical Memorandum 8 – Implementation Testing Plan W052003003SCO TITLEPAGE-CONTENTS.DOC/ 033370021 II FINAL Final Long-Range Biosolids Management Plan Executive Summary The Orange County Sanitation District (the District) currently produces approximately 650 wet tons of digested and dewatered Class B biosolids per day. By the year 2020, biosolids production is projected to increase by about 35 percent. The District relies on land application of its Class B biosolids in Kern and Kings Counties in California, and Class B biosolids land application at the Fort Mojave Indian Reservation in California, Nevada, and Arizona. Moreover, the District is committed to environmentally sound biosolids management practices that meet the stringent federal, state, and local regulatory requirements. Counties throughout California and Arizona have developed, or are in the process of developing, ordinances that severely restrict or ban the land application of Class B biosolids. Recently Kern and Kings Counties banned land application of Class B biosolids. It has become clear that future requirements for managing biosolids will be more restrictive and costs will increase as current options are eliminated. The dynamic regulatory issues, land application ordinances and bans, and public perception challenges prompted the District to develop this Long-Range Biosolids Management Plan. The goal was to develop a sustainable, reliable, and economical program for long-range biosolids management. This Long-Range Biosolids Management Plan includes four major elements: 1. Identify long-term potential Southern California Class A biosolids products and product markets. 2. Identify the onsite and offsite facility options for manufacturing marketable products while optimizing the use of the District’s facilities necessary in treating wastewater. 3. Develop a flexible implementation plan for positioning the District to be able participate in multiple markets. 4. Continue to beneficially use biosolids and maintain conformance with the National Biosolids Partnership (NBP) Code of Good Practice. Long-Range Biosolids Management Plan Development There is a wide range of products that can be developed from biosolids. The strategy for the District will be to focus its resources on developing an economical product for targeted sustainable markets. To develop and select the most sustainable biosolids management options, the consultant team utilized a business-model assessment. First, the long-term sustainable biosolids product markets were identified. Next, the steps necessary to manufacture suitable biosolids-based products for these markets were evaluated. The relationship between the top five long-term sustainable biosolids markets and products that can be generated for these markets is summarized as follows: W052003003SCO/ES.DOC/ 033370011 1 FINAL LONG-RANGE BIOSOLIDS MANAGEMENT PLAN EXECUTIVE SUMMARY x Horticulture – Blending and Bagging for Retail Outlets: Compost, dry pellets and granules, and organo-mineral fertilizer products. x Horticulture – Ornamental and Nurseries: Compost, dry pellets and granules, and organo-mineral fertilizer products. x Horticulture – District Member Cities and Agencies: Compost, dry pellets and granules, and organo-mineral fertilizer products on municipal lands. x Direct Energy Production: Class B biosolids cake and dry pellets. x Silviculture – Shade Tree Programs: Compost or dry pellets and granules, and organo- mineral fertilizer products. Each market consumes several biosolids-based products, and most products can have multiple markets. For example, all five markets accept the dry pellets and granules. Next, the consultant team developed an economic model and also performed an assessment of the product technologies, based on 20 critical implementation factors, including potential odors, traffic impacts, public perception, product sustainability, and ease of implementation/ siting. These two parallel activities allowed for the true cost of each option to be assessed and compared. Based on this evaluation, the most viable biosolids product manufacturing processes are: 1. Composting 2. Heat drying 3. Energy recovery 4. Organo-mineral fertilizer manufacturing This evaluation also determined that diversification of products, product markets, and marketing contracts, as well as the availability of failsafe backup options, are critical elements to protect the District from the effects of weakening markets and failed contracts. These elements are critical because each product market has associated weaknesses, and it will likely take time to develop a product for a new market, contracts with a company within that market, or both. Finally, the District needs to maintain its current land application capacity and options, including the Class A biosolids alkaline stabilization process at its farm in Kings County and other land application sites, for as long as it is feasible and economically sound, while this long-range plan is implemented. Recommendations and Costs The biosolids management program is designed to provide flexibility and allow the District to diversify products and manufacturing through participation in both District-owned and merchant facilities. The consultant team recommends diversification using the following approach, primarily to reduce financial risk: 1. Maintain at least three different product manufacturing options at any given time. 2. Optimize capital and operation and maintenance (O&M) costs at the District treatment plants as part of implementation of the long-range plan. 3. Limit maximum participation for any market to one-half of the total biosolids production. 4. Limit biosolids management contracts to a maximum of one-third of total biosolids production per merchant facility, and one-half per contractor (for contractors with multiple product manufacturing facilities). FINAL 2 W052003003SCO/ES.DOC/ 033370011 LONG-RANGE BIOSOLIDS MANAGEMENT PLAN EXECUTIVE SUMMARY 5. Maximum capacity for each District-owned product manufacturing facility to be one-half of the total biosolids production. 6. Explore funding options for in-county facilities (private capital, District capital, or both). 7. Allocate up to 10 percent of biosolids for participation in emerging markets. 8. Pursue Orange County based product manufacturing facilities and maximize the use of horticultural products within the District service area by member agencies and through developing public-private partnerships. 9. Maintain capacity and options at the District’s Central Valley Ranch. 10. Pursue failsafe backup options (landfilling, alternative daily cover [ADC] for landfills, and dedicated landfilling) to acquire a 100 percent contingency capacity. Table ES-1 presents a summary of the Plant Nos. 1 and 2 onsite improvements, associated capital costs, and the year capacity is needed. With the current biosolids processes, Plant No. 1 dissolved air flotation thickener (DAFT) capacity will be reached in year 2013, digestion capacity will be reached in year 2013, and dewatering capacity will be reached in year 2007. With implementation of the proposed primary and WAS thickening improvements, the need for additional dewatering and digestion capacity will be postponed to year 2013 and beyond year 2020, respectively. At Plant No. 2, the digestion and dewatering capacity is adequate for 2020 predicted loads. However, it is recommended that the existing belt filter presses be replaced with centrifuge dewatering, due to savings in biosolids management costs with drier cake. TABLE ES-1 Onsite Biosolids Management Facilities Cost and Implementation Capital Cost, Onsite Biosolids Processing Facilities Year Capacity Needed Million $1 Plant No. 1 Onsite Biosolids Processing Facilities Primary Sludge Thickening (Centrifuge) 2008 31.2 WAS Thickening Expansion (GBT or Centrifuge) 2013 12.9 Digestion Pretreatment (Ultrasound) Note 2 10.1 Dewatering (Centrifuge) 2007 3 53.7 Plant No. 2 Onsite Biosolids Processing Facilities Digestion Pretreatment (Ultrasound) Note 2 7.7 Dewatering (Centrifuge) Note 4 39.8 Notes: 1The capital costs are for onsite process improvements only. The upgrade of existing digestion facilities will be as planned in the capital improvement program (CIP) and is not included here. 2The District is currently evaluating project delivery options for implementing ultrasound. 3With primary thickening, capacity could be expanded to 2013. 4Plant No. 2 has adequate dewatering capacity through the year 2020. However, centrifuge dewatering will result in reduction of biosolids cake volume and beneficial use costs and should be considered for implementation. GBT = gravity belt thickener W052003003SCO/ES.DOC/ 033370011 3 FINAL LONG-RANGE BIOSOLIDS MANAGEMENT PLAN EXECUTIVE SUMMARY To optimize facilities sizing,