- Written by C&D World News
Identification of Non-Hazardous Secondary Materials that are Solid Waste comments for Docket ID No. EPA-HQ-RCRA-2008-0329
The EPA’s Non Hazardous Secondary Materials Rule as written has an unclear but potentially negative effect on the use of C&D wood as a biomass product. The CMRA Issues & Education Fund has met with EPA officials several times on the rule and also worked in concert with several other trade associations, including the American Forest & Paper Association, affected by the regulation to modify it so that the use of the wood could continue. On the last iteration of the rule the CMRA I&E provided the following comments, which were largely written by Max Lee and Angela Morrison, who have written articles for this magazine on the effect the rule will have on C&D processors.
The Construction Materials Recycling Association (CMRA) is a national organization representing more than 200 companies with operations throughout the United States. The CMRA promotes the recycling of construction and demolition (C&D) materials, and our comments focus on the use of C&D wood as a fuel product, which is renewable and environmentally friendly.
The number of C&D recycling facilities in the United States totals more than 300 mixed C&D operations, and C&D wood fuel is created at these facilities. These operations support LEED-type green building programs, help with state and local mandates to increase and promote recycling, divert landfilled waste, and reduce greenhouse gas emissions. Approximately 33 to 49 mm/ton per year of C&D wood is processed and 4.7 to 6.5 million tons is consumed for energy production each year.1 Unfortunately, most of these C&D recycling operations would be in economic jeopardy without their wood fuel market option. The Non-Hazardous Secondary Materials (NHSM) rule, even with the currently proposed revisions, will severely curtail their processes without further clarification, which is why we are commenting today on the NHSM rule and the proposed revisions under 40 CFR Part 241 (published at 76 Fed. Reg. 80452 on December 23, 2011).
The CMRA supports the comments of the American Forest & Paper Association and the other organizations joining in that letter, which is being submitted on this same date, including the comments directed at the C&D wood industry (referred to herein as the “AFPA letter”). All of these organizations, including the CMRA, have a significant interest in this rulemaking because we use and produce fuels to create energy for our nation.
Basis of Concern
The CMRA is concerned the NHSM rule and all of its ambiguities and inconsistencies, its presumption that all NHSM is a solid waste unless demonstrated otherwise, and the additional requirements that must be met to use C&D wood as a fuel could diminish or even eliminate the market for C&D wood as a fuel. Without this market, the economic viability of C&D recycling operations would be affected to the point where many will close and a ripple effect will cause far less recycling of other materials, such as concrete, metals, asphalt shingles and drywall. The NHSM rule establishes a method for determining if a product made from a secondary material, such as C&D wood fuel, is indeed a waste for purposes of the federal Clean Air Act. If the C&D wood fuel were determined to be a waste and that waste is combusted or used like a raw material, then that combustor or user is regulated for air pollutant emissions as a solid waste “incinerator” (i.e., commercial and industrial solid waste incinerator (CISWI)). We believe that many if not all current users of C&D wood fuel would not continue to use the fuel if it would subject the unit to the CISWI rules. The following comments explain CMRA’s specific concerns and provide suggested improvements to the rule to ensure the viability of this important industry.
Reverting to the 2000 Approach
More than a decade ago, the EPA correctly determined that if materials resulting from commercial or industrial activities are used for energy recovery, then the air incinerator rules are not triggered. Consistent with the 2000 version of the CISWI rules, the EPA should simply clarify that materials used for energy recovery are not waste.
As the American Forest & Paper Association comments explain in great detail, the NHSM rule should not focus on a contaminant comparison to determine whether a material is discarded, and therefore considered to be a fuel or a waste. The EPA has recognized that levels of constituents in secondary material is not a dispositive indicator of whether or not a material is a waste when combusted. In the proposed revisions to the NHSM rule, the EPA proposed a petition process recognizing that a secondary material may have constituents not found in traditional fuel or constituents at higher levels than found in traditional fuel, and still be a fuel and not a waste.2 Thus, the EPA is correctly no longer arguing that constituent levels themselves can determine whether a material is a waste. In fact, the EPA expressly acknowledges in the preamble that a material is not a waste if the purpose of burning is not to destroy or discard, then combustion of the material is not waste disposal.
If in the final rule it remains necessary to consider contaminant levels to determine whether a material is discarded, the CMRA requests further clarification. On page 15,485, column 2, of the March 21, 2011, Preamble for the final NHSM rule, the EPA states: “C&D-derived fuel … likely meets the processing and legitimacy criteria.” This statement indicates that it is an open question as to whether a particular C&D-derived fuel meets these criteria. The EPA made other statements indicating that typical C&D recycling operations sufficiently “process” NHSM, which we appreciate. Meeting the “legitimacy criteria” remains a concern, however. While the legitimacy criteria focused on heating value, processing, and treatment as a commodity are easily met by C&D wood fuel, the legitimacy criteria also require a contaminant comparison to traditional fuels. The CMRA is concerned with the following elements of the “contaminant comparison” as described in more detail below: (1) appropriate contaminants for comparison; (2) groupings of contaminants are appropriate; (3) meaning of “comparable to or lower than” under this rule; (4) traditional fuel database should include international data; and (5) clarify sampling and analytical methodologies.
Appropriate contaminants for comparison—We specifically agree with the EPA’s determination that C&D wood contaminant comparisons could be based on an evaluation of the three metals (mercury, lead, and cadmium) and chlorine in Table I plus arsenic and chromium. In review of the March 21, 2011, Preamble, on page 15,485, the EPA states: “The data provided by one company demonstrates that C&D-derived wood can be sufficiently processed to meet the legitimacy criterion for four contaminants, even when these contaminants are compared to untreated wood concentrations presented in the background document. …A complete determination, however, would include As and Cr concentrations.” The EPA confirmed in the proposed revisions that the it does not expect the proposed revisions to affect any of the decisions previously made on whether NHSMs are solid waste when burned as a fuel.3 Based on the proposed revisions to the NHSM rule, it appears the EPA would also require consideration of other parameters, including nitrogen and sulfur. The CMRA requests confirmation that these five metals and three parameters are the only contaminants that must be compared. Any ambiguity on this point is unnecessary, and certainty as to the contaminants of interest to the EPA is very important for our industry.
Groupings of contaminants are appropriate—The CMRA supports the EPA’s proposal to group contaminants for purposes of comparisons. Based on the EPA’s discussion of potential grouping of contaminants, the CMRA requests the EPA confirm metal groupings for C&D wood would include two groups: volatile metals (lead and mercury) and non-volatile metals (arsenic, chromium, cadmium). We agree with the EPA’s proposal to allow other types of groupings beyond than those identified in the proposed revisions.
Meaning of “comparable to or lower than” —In the March 21, 2011 Preamble, the EPA stated that a cadmium level of 0.065 parts per million in coal of an unknown source or type was “comparable” to a level of 0.179 parts per million in C&D wood. See Table 1, copied from the preamble. We understand that arsenic and chromium would also need to be compared, but assuming the levels of arsenic and chromium are indeed comparable, then this part of the legitimacy test would be met.
In addition, the EPA’s Preamble statements indicate it would be appropriate to compare values based on the “upper end of its statistical range.” This terminology is not further defined or explained, and there are number of different ways this could be determined. We believe the upper prediction limit (UPL) at 90% is appropriate to determine the upper range of a secondary material’s contaminants. We believe that the UPL at 90% for the secondary material should be compared to the high range of the data for the traditional fuel.
If data result in non-detected values, one-half of the minimum detection limit should be applied. If data result in values less than the minimum reporting level but above the minimum detection limit, the minimum detection level value should be applied. Without this clarity, the EPA cannot expect industry to have confidence in any attempt to legally define its NHSM as non-waste fuel. The industry must have a bright line that determines its compliance.
Traditional fuel database should include international data—The reference to a “national” survey presumably includes international data as well, but that should be clarified. Certainly the traditional fuel database should include data from USGS of coal and other fuels from not only the U.S. but also from around the world because those fuels are currently in use. Furthermore, the EPA has already included international data sources for traditional fuels in the currently web-post.4
Clarify sampling and analytical methodologies—The CMRA supports the EPA’s approach in the NHSM rules that sampling and analysis are not required for the contaminant comparison. Though, as elaborated on the AFPA letter, the presumption that secondary material is solid waste imparts a burden upon the generator and combustor such that sampling could be used to rebut such a presumption. Even though sampling is not explicitly required for NHSM comparison assessments, if an NHSM generator or combustor were to undertake such sampling, the EPA should provide improved guidance on sampling methodology to ensure representative sampling and guidance on analytical methodology to ensure consistent quality assurance of analytical results.
National Determinations & Categorical Exemptions
CMRA supports the EPA’s proposed petitioning process for categorical exemptions and suggests that the EPA continue to issue comfort letters. The CMRA requests a categorical exemption for processed C&D wood fuel generated at facilities under contract for collection, processing, and distribution of C&D wood and using best management practices, without regard to individual units in which the wood might be used, as the EPA has done with its determinations for tires and resinated wood.
The EPA has clearly applied contractual agreements to differentiate between tires identified as waste and tires that are not waste (i.e., tires maintained under some form of contractual agreement prior to disposal).5 Further, the EPA recognizes that “a contractual arrangement that ensures that scrap tires are not discarded and are handled as valuable commodities through arrival at the combustion facility” is evidence that the tires handled under such contracts are not wastes. 76 Fed. Reg. at 80484 and proposed 40 CFR 241.2 (defining “established tire collection program”). Most important, the EPA addresses the practical nature of the contractual agreement in which the combustor does not have to have perfect knowledge of the source of this secondary fuel and does not require the combustor to test that fuel. “Rather, it is sufficient that the ultimate user verify that it is obtaining tires from an established tire collection program, which program can provide the user with reasonable assurance that it manages tires carefully from point of collection to point of burning and which does not receive tires which have been abandoned in landfills or otherwise.” 6
The CMRA’s Best Management Practices (BMPs) (see sidebar) for recognized industry practice are used throughout the industry and are responsible for the high quality C&D wood fuel that is readily available. The practices set forth in the attached BMPs and related analytical data from facilities implementing such BMPs demonstrate that the processed fuel is clean and compares favorably to traditional fuels. The EPA has generally agreed that processed C&D wood meets the contaminant legitimacy criteria. Processed C&D wood also meets the other legitimacy criteria of proposed 40 CFR 241.2. Processed C&D wood is managed as a valuable commodity; it is purchased under contracts and is managed like the valuable commodity that it is. C&D wood fuel has meaningful heating value, with sample higher heating values ranging averaging 8440 Btu/lb, equivalent to or greater than forest-derived biomass fuel.
Similar to tires and resinated wood, C&D wood is comparable to traditional fuels. It should be noted that a comparison of tires was made only to coal, whereas, Table 2 (see sidebar) provides a comparison to coal, biomass and oil.
Again, the CMRA requests a categorical exemption for processed C&D wood fuel generated at facilities under contract for collection, processing and distribution of C&D wood, and using best management practices, without regard to individual units in which the wood might be used, as the EPA has done with its determinations for tires and resinated wood.
When an Assessment Must be Made
CMRA supports the EPA’s clarification that a combustor need not test traditional fuels for contaminant levels and may rely on the data provided by the EPA or other surveys. 76 Fed. Reg. at 80477. We support the EPA’s clarification that a combustor may use data from any traditional fuel source, not just fuel from its own supplier. We support the EPA’s clarification that data on contaminant levels in non-hazardous secondary materials may be based on survey data such as data collected by a trade association.7 We support the EPA’s clarification that a combustor may use process knowledge to determine that a constituent will not be found in its secondary material and does not need to test that material to document this determination.8 Finally, we support the EPA’s clarification that: “An initial assessment [of contaminant comparability] would not generally need to be repeated, provided the facility continues to operate in the same manner and use the same type of NHSMs as when the original assessment was made.” 9 Based on this statement, we believe the EPA would allow a combustor to rely on the initial assessment of comparability unless the combustor had reason to believe that the NHSM had significantly changed. The provided analytical data and analyses in the AFPA letter of C&D wood from a broad spectrum of facilities that collect C&D wood from various sources is indicative of the consistent and comparable nature of C&D wood and the limited change expected to occur in these facilities. Please confirm that this is the EPA’s intent. If so, these changes will result in fewer non-hazardous secondary materials being arbitrarily identified as wastes.
The CMRA appreciates the EPA’s review and consideration of these comments and suggestions. If you have any questions or would like further information from us, please do not hesitate to contact us.
1 Materials Characterization Paper In Support of the Final Rulemaking: Identification of Nonhazardous Secondary Materials That Are Solid Waste Construction and Demolition Materials – Building-Related C&D Materials (Feb. 3, 2011) (EPA-HQ-RCRA-2008-0329-1811).
2 76 Fed. Reg. at 80482
3 76 FR 80470
4 “Contaminant Concentrations in Traditional Fuels: Tables for Comparison,” November 29, 2011 (EPA-HQ-RCRA-2008-0329-1877)
5 76 Fed. Reg. 80471, 80476
6 76 Fed. Reg.28318, 28322 (May 17, 2011)
7 76 Fed. Reg. at 80481
8 76 Fed. Reg. at 80477
9 76 Fed. Reg. at 80481
10 76 Fed. Reg. 80481
11 U.S. Environmental Protection Agency (1995), Guidance for the Sampling and Analysis of Municipal Waste Combustion Ash for the Toxicity Characteristic, EPA 530-R-95-036, June 1995.
12 76 FR 80485
How C&D Wood Biomass is Created
Construction and demolition (C&D) biomass is the material generated during building construction and demolition activities. The EPA’s most recent estimate of building-related C&D generation is 156 mm/tons in 2007. The wood portion of that material is approximately 40 mm/tons. Use of this biomass product as a fuel is an excellent example of sustainable materials management.
Clean construction and demolition biomass is considered a “traditional fuel” by the EPA. The production of this renewable fuel takes several steps from generation to end use.
Demolition Site: By regulation, the wood is tested for lead-based paint at the demolition site. If lead-based paint is detected on the wood or other parts of the building, the paint is managed as required by government regulations. Processing then begins when the wood is separated at the demolition site into painted and unpainted wood, or it can be co-mingled with other materials generated at the site and sent to a processing facility for sorting and classification.
Construction Site: The wood can be separated into a separate bin or placed in a container commingled with the other materials generated at the site. Often wood generation “spikes” during the construction process. For example, wood waste generation spikes during the framing process on housing. Additional emphasis on wood processing occurs during these spikes. Construction sites do not generate painted wood.
C&D Recycling Facility: After initial processing at a construction site, material is transferred to a recycling facility for additional processing. In some cases, material is taken directly to the recycling facility for processing. Further processing in the plant occurs when the material is sorted into the various constituents, such as wood, metals, concrete, etc. This is to ensure the removal of as much deleterious material as possible. Both mechanical and human sorting methods are used. C&D recycling facilities are heavily regulated, in most cases by state departments of environmental protection under regulations adopted within the State Administrative Code. Permits are necessary as either recycling facilities or materials recover facilities and sites are regularly inspected by enforcement personnel to gauge compliance.
At the processing facility, incoming material is inspected on the tipping floor for contaminants. Inspection can be visual using trained inspectors or mechanical using testing analyzers. Any suspicious wood is either rejected or set aside. Although most contaminants are removed at the point of generation, this is an extra level of examination before the material enters the facility’s sorting and sizing process. For C&D wood fuel, unacceptable wood products would include CCA wood and most painted wood. Non-combustibles such as metals and aggregate materials are also considered to be unacceptable.
After separation, the wood is ground to a specified size. This processing can produce a large grind, such as an 8-inch minus product that will again be ground at the biomass boiler, or a smaller size such as 2-inch minus ready to be fed into the boiler.
The next step is to test for contaminants. Testing occurs at the recycling facility or at the biomass facility, often both. Several types of tests can be performed on the finished C&D biomass. Testing requirements and parameters are established through facility permit documents and are monitored by environmental enforcement agencies.
Further, C&D wood quality and level of contaminants are limited by boiler/kiln system vendor and manufacturer guarantees and warranties. Noncompliance can void such warranties.
Biomass Facility: The wood is again inspected visually and may be tested mechanically. The wood is then used in the boiler for power generation. Afterward the ash is disposed of in a landfill.
The use of C&D wood as a fuel is highly regulated at the state level. The product must be capable of being safely burned in the boiler and must not cause emissions that would lead to an air permit violation. C&D wood fuel customers take their permit requirements seriously and will not tolerate shipments that endanger their permits. As a result, most biomass facilities will inspect a C&D recycling facility before they accept the first load from it.
Unannounced inspections of the C&D processing facility by biomass plant personnel are common. Boiler operators also place restrictions on the size of the fuel, as well as deleterious materials such as plastics, inorganics and metals. Boiler operators are purchasing a fuel that will work efficiently and cost-effectively in their facility. They will not risk their boiler’s performance or their air permit requirements with a subpar fuel.
If C&D wood is considered a waste wood and combustors would become subject to CISWI if the material is used as a fuel, or if additional testing is required by the combustors, the market for C&D wood fuel will not be economically viable. As stated in the AFPA letter, for example, two trailers of C&D wood have a value between $700 and $900. One composite sample from each trailer could cost $2,000 to analyze. The turnaround time for the sampling is likely to be seven days. The cost of holding the trailers on-site could be an additional $1,000. Tthe costs of ensuring that the regulatory requirements of the NHSM rule are met could cost a combustor of C&D wood over twice the value of fuel. Such a scenario would make it cost prohibitive and shut down many of these alternative energy facilities across the country, increasing America’s reliance on fossil fuels.
Comparison of Contaminant Concentrations in C&D Wood with Traditional Fuels
On November 29, 2011, the EPA published a document titled “Contaminant Concentrations in Traditional Fuels: Tables for Comparison.” This document contained ranges and averages for contaminant concentrations in three common traditional fuels namely coal, biomass and fuel oil. The EPA indicated that members of the regulated community could use the data when comparing contaminants in their non-hazardous secondary materials (NHSMs) to contaminants in the appropriate traditional fuels. The EPA presented three tables with contaminant data summarized from both the scientific literature and the EPA databases for coal, wood/biomass and fuel oil. In this report, the contaminant data for one NHSM that is frequently burned in industrial boilers, namely wood fuel derived from construction and demolition (C&D) operations or C&D wood, is compared with those compiled by the EPA for the three common traditional fuels coal, biomass and fuel oil.
The EPA provided guidance in the Federal Register notice announcing the proposed revisions to the NHSM rules (EPA 2011) on what contaminant comparisons are allowed as follows: “Given data for a particular traditional fuel, it makes intuitive sense to base the traditional fuel comparison value on the upper end of its statistical range.”10 However, the EPA does not elaborate on what is specifically meant by “the upper end of its statistical range.”
Given that the EPA’s compiled data for the traditional fuels coal, biomass and oil are presented as means and ranges (min and max), two approaches are proposed here for the C&D wood contaminant comparison, each of which could serve as a suitable indicator to be compared with the maximum of the traditional fuel. The first approach uses an Upper Prediction Limit (UPL), while the second uses an Upper Confidence Limit (UCL) of the mean. At a specified confidence level (CL), the UPL is an indicator of what a future measurement would look like based on the current available data set for the contaminant in the candidate NHSM. For the same data set, the UCL of the mean predicts the upper bound for the mean of several future measurements for a contaminant in the candidate NHSM at a given facility (again at a specified CL). The UCL approach has previously been used by the EPA in the context of municipal waste combustion ash where a two tailed 80% UCL (one-tailed 90% UCL) is used to compare ash testing results with hazardous waste toxicity thresholds.11 The EPA also cites the 90% confidence interval in its NHSM preamble discussion of pulp and paper sludge.12
The maximum in the traditional fuel data set and not a value in the upper end of its statistical range is chosen for this comparison with the subject NHSM since all data corresponding to the traditional fuel are valid for comparison and not just values that are below some arbitrarily determined statistical parameter. This method coincides to the EPA statement, “Anything less could result in ‘‘traditional fuel’’ samples being considered solid waste if burned in the very combustion units designed to burn them—not the agency’s intent in either the 2011 NHSM final rule or today’s proposed rule.”
It should be pointed out that for such comparisons to be useful to the regulated community, the EPA needs to “freeze” the current data set it has compiled for the traditional fuels for a given comparison to remain valid.
A UPL or UCL based on a 90% confidence level is proposed to be compared with the maximum value for traditional fuels in the OAQPS databases. Relative to contaminants in C&D wood, only HAP metals, Cl, halogens, S and N are relevant since C&D wood is not expected to contain any organic HAPs (at least beyond trace levels). In order to evaluate the characteristics of typical processed C&D with the contaminant comparability criterion, NCASI obtained 10 years of testing data from a total of 142 processed C&D wood samples collected at a New York State biomass-to-energy facility. During that time, the facility combusted processed C&D wood from an estimated 25 different suppliers located in the Western New York region and Ontario, Canada. Sampling and analyses were performed in accordance with an Alternate Fuels Quality Assurance/Quality Control Plan required under fuel testing provisions of the facility’s Title V permit. The QA/QC Plan also included requirements to evaluate processor procedures, and provisions for material receipt, storage and inspection, training of both processor and combustion facility personnel, and recordkeeping. The samples consisted of mixtures of as-fired, processed C&D material taken from the boiler feed conveyor; some samples may have included insignificant amounts of non-C&D wood. Grab samples were taken once every 12-hour shift during unit campaigns and composited using cone and quarter techniques into weekly samples for analysis. Reported analytes included arsenic, cadmium, chromium, lead, mercury, chlorine, fluorine, sulfur, higher heating value, ash content and moisture content. Covanta Energy Corp., the facility’s operator, compiled results from laboratory reports and provided them to NCASI for statistical analysis. Covanta is separately submitting a tabulation of the results to the NHSM docket.
The analytical data included five of the 11 HAP metals (arsenic, cadmium, chromium, lead, and mercury), halogens (Cl + F), and S. These five are typically the only HAP metals analyzed for in C&D wood (note EPA recommended in Table 1 of the March 21, 2011, NHSM rule to analyze C&D wood for chlorine, cadmium, lead, mercury, arsenic and chromium), the rest being expected to be similar to unadulterated wood biomass.
Comparison of HAP Metals, Halogens and S
The EPA’s PROUCL 4.0 program (EPA ProUCL) was used to estimate the 90% UPL values for each contaminant data set. The program identifies the type of distribution that best fits a particular set of data. The 90% UPL value is chosen for that type of distribution. The 90% UCL value is simply the sum of the arithmetic mean and the product of the standard deviation and the TINV function at 90% UCL.
Table 2 presents a summary comparison of the traditional fuel data compiled by the EPA with the minimum, maximum, mean, 90% UPL and 90% UCL for the C&D wood data set. It is seen that for all 5 HAP metals and TSM, both the 90% UPL and 90% UCL values for the C&D samples are less than the corresponding maximum for biomass, and significantly less than that for coal. Here the TSM comparison is carried out with TSM representing just the five HAP metals for which data were available for C&D wood (As, Cd, Cr, Pb and Hg). Although the TSM estimate for C&D wood does not include values for Be, Co, Mn and Se, these metal HAPs are expected to be present only at levels found in virgin biomass, and thus the comparison with the full TSM set would still be favorable. Chlorine and total halogens (Cl + Fl) in C&D wood compare favorably with both biomass and coal. S in C&D wood also compares favorably with coal.
Based on the comparison laid out in Table 2 for the five key HAP metals, halogens, and S in C&D wood, it should be concluded that the contaminants in C&D wood compare very favorably with the three traditional fuels coal, biomass and oil, thus warranting a “non-waste fuel exemption” to this NHSM, similar to that given to tire-derived fuel and resinated wood.