BOARD MEETING DATE: April 5, 2002
AGENDA NO. 34

Prehearing and Status Report on Controlling Volatile Organic Compound and Ammonia Emissions from Composting and Related Operations

SYNOPSIS: 

As part of the development of Proposed Rule 1133, (Control Measure WST-02), staff has been evaluating methods to control emissions from composting operations. The 1999 amendment to the 1997 AQMP requires staff to report to the Board, at a public meeting, when cost-effectiveness for a draft rule may exceed $13,500 per ton of VOC reduced. The report must be presented at least 90 days prior to rule adoption and include viable control alternatives within the industry source categories to be regulated. This report fulfills this obligation and provides an update on source tests, potential control technologies, cost-effectiveness and potential industry impacts, with recommended actions to reduce emissions from composting operations. The report and staff recommendations also fulfill the commitments of WST-02.

COMMITTEE: 

Stationary Source, December 7, 2001 and January 25, 2002, Reviewed

RECOMMENDED ACTION:

Direct staff to:

1. Present Proposed Rule 1133 – Emissions from Composting and Related Operations based on the recommendations in the Technology Assessment for Board consideration no later than fall 2002;
   
    
2. Establish a Technical Advisory Committee to oversee on-going technical studies of cost-effective composting control technologies and management practices; and,
   
    
3. Work with all stakeholders, including the California Integrated Waste Management Board, local municipalities, and sanitation districts, to seek sources of funding for control technology for use by the greenwaste composting industry.

Barry R. Wallerstein, D.Env.
Executive Officer

Background

The 1997 Air Quality Management Plan (AQMP) and the 1999 Amendments to the 1997 Ozone State Implementation Plan (SIP) for the South Coast Air Basin included Control Measure WST-02 – Emission Reductions from Composting. As described in WST-02, the control measure was to be implemented in two phases. The first phase was to better quantify emissions from composting activities. AQMD staff has conducted source tests at major local composting facilities using a variety of composting feedstocks. In addition, AQMD staff is reviewing the latest source tests of greenwaste composting and processing sites conducted by the California Integrated Waste Management Board (CIWMB) and the City of Los Angeles. AQMD staff also conducted a survey of over 600 potential composting and related operations to identify facilities potentially subject to the proposed rule. The attached Technology Assessment of Proposed Rule (PR) 1133 – Emissions from Composting and Related Operations (PR 1133 Technology Assessment) describes the industry profile and estimated emissions. The second phase of WST-02, to be implemented if emissions from composting and related operations continued to be significant, was to identify control options to reduce emissions from composting activities that were technically feasible and cost-effective. As determined in the first phase, composting and related operations are a significant source of ammonia and VOC emissions. The PR 1133 Technology Assessment describes potential control options, their technical feasibility, and cost-effectiveness. Thus, the PR 1133 Technology Assessment fulfils the requirements of control measure WST-02. Due to the high cost of the identified control options and the potential impact on the greenwaste composting industry, in particular, staff is recommending only limited implementation of composting controls at this time. As further research is conducted, AQMD staff anticipates improved estimates of emission reduction effectiveness and implementation costs will be available. At that time, AQMD staff may recommend further controls on composting and related operations.

The 1999 Amendments to the 1997 AQMP requires staff to report to the Board, at a public meeting, when cost-effectiveness for a draft rule/amendment may exceed $13,500 per tons of VOC reduced. Initial rule development efforts, based on general control option scenarios, indicated that the cost-effectiveness to implement this control measure might exceed $13,500 per ton of VOC reduced, depending on the control options chosen. To comply with the 1999 AQMP commitment, staff is bringing before the Board the PR 1133 Technology Assessment. Based on Board direction, AQMD staff will proceed with PR 1133 rule development.

Industry Profile

The composting and related operations industry within the AQMD’s jurisdiction includes 277 facilities categorized as follows: co-composting facilities; greenwaste- only composting facilities; chipping and grinding facilities; and, exempt facilities. Co-composting facilities use putrescible materials, such as wastewater sludge, manure, or food waste in combination with greenwaste as their process feedstock. Greenwaste composting facilities are composting facilities that only use greenwaste as process feedstock. Chipping and grinding facilities are facilities dedicated to the size reduction of greenwaste for uses such as alternative daily cover, biomass fuel, mulch, or composting feedstock. Finally; exempt facilities are facilities that are part of this industry but are likely to be exempt from regulation under Proposed Rule 1133, such as backyard composting and off-site chipping and grinding.

Emissions Inventory

The baseline emissions inventory estimated for the industry is 4.7 and 6.8 tons per day for ammonia and VOC, respectively. The co-composting emissions inventory is estimated at 3.7 and 2.2 tons per day of ammonia and VOC, respectively. The greenwaste composting emissions inventory is estimated at 1.0 and 4.4 tons per day of ammonia and VOC, respectively.

The seven largest co-composting facilities are estimated 1310 tons per year of ammonia and 796 tons per year of VOCs; the three largest individually emit 100 to 300 tons per year of VOC and 150 to 500 tons per year of ammonia. The ten largest greenwaste composting facilities are estimated to emit 1,570 tons per year of VOCs; the three largest facilities individually emit 250 to 600 tons per year of VOC emissions, which would rank them among the largest VOC stationary source facilities in the Basin.

The baseline emission inventory is based on source tests and emissions studies conducted by AQMD staff. The CIWMB and the City of Los Angeles conducted a series of source tests at greenwaste processing and composting facilities in December of 2001. Although the final results have not been completely reviewed by AQMD staff in time to be included in this report, AQMD staff will incorporate those test results to the greenwaste composting emissions analysis and report the revised analysis to stakeholders as soon as possible. Based on a preliminary review of these source test results, it is not anticipated that they will significantly alter the conclusions or recommendations in the PR 1133 Technology Assessment.

Technology Assessment

Staff has conducted a technology assessment of the composting and related operations industry. It reviews the composting methods available to industry including the following composting methods: windrow, aerated static piles (ASP), and in-vessel. Emissions from ASP and in-vessel systems can be vented to control equipment, such as biofilters. ASP and in-vessel systems can also be enclosed, with all emissions vented to control equipment. With the exception of one facility that uses the enclosed in-vessel method of composting, open windrow composting method represents the current state of the co-composting industry in Southern California. For greenwaste composting the predominant method of composting is large mounded static piles for composting. The analysis evaluated in-vessel or ASP systems with various degrees of enclosure in combination with bio-filtration systems. Currently, there are approximately 118 operational composting facilities in the U.S. utilizing the ASP technology, two of them is located in the District. Nationwide, these facilities handle a daily throughput ranging from about 0.1 dry ton to 300 dry tons. In addition, several groups in the District also consider ASP for their future co-composting facilities. There are approximately 50 operational composting facilities in the U.S. utilizing in-vessel technology; one of them is located in the District. These facilities handle a daily throughput ranging from less than 1 dry ton to over 100 dry tons. Based on this analysis, AQMD staff demonstrated that there are technologies that can significantly reduce emissions from the composting and related operations.

Control Options and Socioeconomic Analysis

AQMD staff developed three control scenarios to evaluate the potential emission reductions and cost of controlling composting emissions.

• Scenario one assumes the enclosure of the active and curing parts of the composting process, the use of an ASP or in-vessel system, and venting of emissions to a control device (i.e., biofilter).
• Scenario two assumes enclosure of the active phase of the process and the use of an ASP or in-vessel system with emissions vented to controls. For the curing phase of the process, scenario two has a variation for co-composting and the greenwaste composting. For co-composting, scenario two assumes the use of a negative-pressure ASP system with emissions vented to controls (no enclosure). For the greenwaste composting, scenario two assumes no controls for the curing phase of the process.
• Scenario three assumes the use of a negative-pressure ASP system for both the active and curing phases of the process with emission vented to controls (no enclosures).

In should be noted that there may be additional emission reductions associated with ASP systems that have not been quantified as part as the staff analysis (e.g., reduced pile emissions due to forced aeration). Additional testing of ASP systems would allow the emission reduction potential of all control scenarios to be refined.

As part of the cost analysis, AQMD staff has analyzed compliance costs, cost-effectiveness and compliance affordability. Co-composting produces significant amounts of both ammonia and VOC emissions. Because controls reduce both ammonia and VOC emissions, AQMD staff is reporting cost-effectiveness based on combined ammonia and VOC reductions. Control options for the co-composting sector of the industry are seen as feasible and effective and have a great potential for reducing emissions and other related environmental problems. To summarize, if the seven largest co-composting facilities were controlled:
 

Note: Cost and cost-effectiveness are based on fabric enclosures. Cost-effectiveness based on combined ammonia and VOC emission reductions. VOC cost-effectiveness is approximately twice the combined cost-effectiveness.

The most cost-effective control scenarios (scenarios one and two) are those that include enclosure of some parts of the composting operation; however, enclosure is very costly.

The major type of emissions from greenwaste composting is VOCs. Controls would result in concomitant ammonia emission reductions, but the focus of the control program would be VOC emission reductions. To summarize, if the ten largest greenwaste composting facilities were controlled:
 

Note: Cost and cost-effectiveness are based on fabric enclosures. Combined (VOC and ammonia) cost-effectiveness is about 15% lower than VOC cost-effectiveness.

The control options for greenwaste composting sector of the industry could result in significant VOC emission reductions and, on a VOC basis, are more cost-effective than for co-composting operations. However, the affordability analysis, as presented in Chapter IV of the PR 1133 Technology Assessment and described below, demonstrates that the cost impact for this industry would be substantial.

Compliance costs are about $22/ton of throughput for both co-composting and greenwaste composting (scenario two). However, greenwaste composting tipping fees are less than co-composting tipping fees ($12 to $25 per ton for greenwaste vs. $20 to $40 per ton for co-composting). Additionally, product fees are less for greenwaste composting (~$20/ton) vs. co-composting (~$30/ton). Lastly, most greenwaste composting operations are privately owned and operated. Most co-composting operations are public/private partnerships (public ownership with private operators), where the public agency is responsible for biosolid disposal. Thus, operators of greenwaste facilities will have significantly more difficulty affording emission controls than co-composting operations, based on today’s business conditions. If costs were sufficiently high and the private operators chose not to continue operations, greenwaste composting could not be used to the extent it is used today as a waste diversion option. On the other hand, public wastewater and sanitation agencies are generally responsible for managing their biosolids. As other disposal options decrease due to regulations (e.g. land spreading restrictions) or increase in cost, and siting of local open-windrow facilities becomes more difficult due to public health and nuisance concerns, local wastewater and sanitation agencies are actively pursuing enclosed and controlled composting facilities to ensure long-term disposal for their biosolids. Three of the four largest co-composting operations in the District are already preparing to move into facilities that meet or exceed scenario two controls and close those existing operations. Based on the AQMD staff’s recommendation, reductions from these projects could be tracked and credited in the SIP.

Recommendation

Based on information documented in the PR 1133 Technology Assessment, staff is recommending that AQMP Control Measure WST-02 – Emission Reductions from Composting and Related Operations, be implemented in two phases. The first phase would consist of an adoption of a rule that would have the elements listed below. The first phase would also include control requirements for new co-composting facilities with total throughput design capacity of 100,000 tons per year. The specific details of PR 1133 would be based on Board direction and continued Working Group and public review and comment during the rule development process. The second phase would consider additional composting control technologies for new and existing facilities when cost-effective control options are identified.

Co-Composting
As described in the PR 1133 Technology Assessment, co-composting facilities are major sources of VOC and ammonia emissions (e.g., a 100,000 ton/year total throughput facility has potentially annual emissions of 89 tons/year VOC and 147 tons/year ammonia). Staff recommendations summarized below, acknowledge the cost issue associated with existing facilities and the control potential at large new facilities. AQMD staff recommendations are as follows:

   Existing and New Co-Composting Facilities

• One-time registration with AQMD;
• Annual reporting requirements;
• PM10 controls to prevent visible PM10 emissions over the property line during operations and from compost piles; and
• Compliance with all applicable AQMD rules, regulations and permit conditions.

   New Co-Composting Facilities with a Design Capacity > 100,000 tpy

• Scenario two control requirements for new facilities with total throughput designed capacity of 100,000 tons per year;
  Enclosure and ASP for the active phase of the process with emissions
         vented to a control system (e.g. biofilters);
  Open ASP for the curing phase of the process with emission vented to
         a control system (e.g. biofilters);

Greenwaste Composting
As described in the PR 1133 Technology Assessment, the greenwaste industry represents a significant source of VOC emissions and its control options in general are more cost-effective. However, the affordability analysis indicates that these controls could have significant impacts on the industry. As a result, the staff is proposing minimal requirements on the industry at this time and the proposed requirements would primarily track its operations and emissions inventory and to claim inventory reductions should site-specific controls be implemented. The following summarizes the proposed requirements for existing and new greenwaste composting operations.

• One-time registration;
• Annual reporting requirements;
• PM10 controls to prevent visible PM10 emissions over the property line during operations and from compost piles; and
• Compliance with all applicable AQMD rules, regulations and permit conditions

Chipping and Grinding Operations
Chipping and grinding operations can be sources of PM10 and VOCs. PM10 results from the chipping, grinding and screening of green materials. It can also result when high winds entrain material from processed material piles. Chipped and ground material that is not removed or further processed can decompose anaerobically, resulting in odors and higher levels of VOCs. To address these issues, AQMD staff is proposing the following requirements:

• One-time registration;
• PM10 controls to prevent visible PM10 emissions over the property line during operations and from processed material piles;
• Holding time restrictions on curbside fines and processed green material piles; and
• Compliance with all applicable AQMD rules, regulations and permit conditions

Funding for Greenwaste Composting Controls
In light of the fact that there are cost-effective control options for this industry that are not yet affordable, AQMD staff is recommending that, through the District’s Legislative Committee, special funding from the state legislature be sought to implement state-of-the-art composting methods, including but not limited to, enclosed ASP. AQMD staff will work with the CIWMB and CARB to seek additional funding and/or make existing waste management funding available to address air quality impacts. Projects could include pilot studies of controlled greenwaste composting operations, and control effectiveness studies of feedstock and management practices, alone and in combination with ASP systems.

Technical Advisory Committee
Finally, AQMD staff is further recommending that a Technical Advisory Committee be formed and serve as a forum to address on-going technical work on cost-effective control technologies and management practices related to Proposed Rule 1133. An example of this technical work is the proposed control technology study by Southern California Association of POTWs (SCAP) on open ASP co-composting. Pilot enclosed ASP co-composting facilities will begin locally in 2003. Technical, operational, and cost data from these and related projects will be used to revise the cost and effectiveness analysis of composting controls. There will be annual status reports to the AQMD Stationary Source Committee on facility emissions and the feasibility of implementing additional cost-effective controls.

Attachments

1. Technology Assessment for Proposed Rule 1133 – Emissions from Composting and Related Operations.

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