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On October 30, 2009, the U.S. Environmental Protection Agency (EPA) codified its Mandatory Reporting of Greenhouse Gases Rule (Rule) at 40 CFR Part 98 of the Federal Register.  Under the Rule, suppliers of fossil fuels or industrial greenhouse gases, manufacturers of vehicles and engines, and facilities that emit 25,000 metric tons or more per year of greenhouse gas (GHG) emissions are required to submit annual reports to EPA.

The Rule categorically exempts the municipal wastewater treatment process from the reporting requirements.  However, municipal wastewater treatment facilities may still be required to calculate their emissions and potentially report to EPA depending on the quantity of emissions from the combustion of fossil fuels in stationary combustion units (as defined in Subpart C of the Rule) at the facility.  Subject facilities are required to determine reporting requirements during 2010, with the first reports due on March 31, 2011.

In addition, a recent EPA rule added three new reporting requirements to the General Provisions (Subpart A) of the Rule, including parent company information, industrial sector codes, and whether or not reported emissions include emissions from cogeneration facilities.

This Advocacy Alert summarizes the relevant provisions of the Rule and highlights other requirements of interest to members, both in the Rule and in several subsequent amendments.  On August 11, 2010, EPA proposed significant amendments to the Part 98 reporting requirements.  NACWA has reviewed these amendments and believes there could be changes that affect those clean water agencies that are required to calculate their emissions.  EPA plans to finalize the changes by the end of 2010 and NACWA will update the membership on how such changes may impact their reporting obligations.

Mandatory Reporting of Greenhouse Gases Rule

The Rule categorically exempts the centralized domestic wastewater treatment facilities from reporting requirements.  However, a wastewater treatment facility will be required to calculate its emissions and report depending on the heat input capacity and calculated emissions from stationary combustion sources located at the facility.

Determining Applicability

To assess whether a wastewater treatment facility is required to report its emissions under the Rule, the first step is to identify all stationary fuel combustion sources and corresponding rated heat input capacities.  The Rule defines stationary fuel combustion sources to include the following:

1. Boilers
2. Process heaters
3. Stationary internal combustion engines
4. Combustion turbines
5. Incinerators
6. Other stationary fuel combustion equipment

Emergency generators or other portable equipment are not included.

Once an inventory of stationary combustion sources is completed, the aggregate maximum rated heat input capacity needs to be determined.  Under Subpart C of the Rule, owners of water treatment facilities must follow these procedures:

1. Determine whether the aggregate maximum rated heat input capacity from all stationary fuel combustion sources is greater than or equal to 30 million Btu/hour (mmBtu/hr).
   
   
2. If the aggregate maximum rated heat input capacity meets or exceeds the 30 mmBtu/hr threshold, then GHG emissions from stationary fuel combustion sources must be calculated.  This does not yet indicate that emissions reporting is necessary.

If the aggregate maximum rated heat input capacity does not meet or exceed the threshold, then the facility is required to do nothing further.  Even if no further action is required, NACWA recommends that its members keep a record of their heat input capacity determinations.

For facilities that exceed the rated heat input capacity threshold, total annual GHG emissions from the stationary fuel combustion sources must be determined.  Keep in mind that these calculations need only be developed for the total annual mmBtu generated by these sources in the aggregate.

Calculating Emissions

The Rule directs that the determination and reporting of emissions from stationary fossil fuel combustion sources be limited to carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) and directs that emissions be calculated using the following default natural gas and fuel oil emissions factors:

The Rule provides four methodological “tiers” to determine emissions:

• Tier 1 uses annual fuel consumption records, fuel-specific heat values, and default CO₂ emissions factors.
• Tier 2 is similar to Tier 1 but uses measured fuel-specific heat values.
• Tier 3 uses recorded or directly measured fuel consumption values and periodic measurements of fuel carbon content.
• Tier 4 uses existing continuous emission monitors (CEMS) that meet specific fuel type and hours of operation criteria.

The tier used by a facility depends on unit size, type of fuel combusted, and other factors.  For the calendar year 2010 reports that are due in March 2011, all facilities that must report emissions from stationary fuel combustion sources only may use the Tier 1 methodology.  After this first reporting year, facilities must determine which tier is applicable.  Most wastewater utilities will be able to use the Tier 1 method; however, Tier 2 may be required for some utilities ^[1].

If a facility determines that its GHG emissions exceed 25,000 metric tons of carbon dioxide equivalents (MtCO₂e), the emissions then must be reported to EPA or designated state agency on an annual basis.  Table C-1 to Subpart C of the Rule lists the types of fuels for which CO₂ emissions must be reported and provides default high heat values and CO₂ emissions factors.  Emissions of CH₄ and N₂O are required only for units required to report CO₂ emissions and only for fuels listed in Table C-2, which provides default CH₄ and N₂O emissions factors.

When determining if a facility exceeds the 25,000 MtCO₂e threshold, CH₄ and N₂O emissions from biomass fuels are included, but CO₂ emissions are not.  If the threshold is exceeded, however, CO₂ emissions from biomass fuels must also be calculated and reported.  The Rule does not require the determination or reporting of emissions from the combustion of biosolids or skimmings, which are not listed in Table C-1.  However, emissions related to biogas combustion emissions must be calculated and reported.  For biogas, Table C-1 of the Rule provides a default high heat value of 0.841x10^-3 mmBtu/scf and a default emissions factor of 52.07 kg CO₂/mmBtu.  Biogas CH₄ and N₂O emissions factors from Table C-2 are 3.2x10^-3 kg CH₄/mmBtu and 6.3x10^-4 kg N₂O/mmBtu, respectively.

Reporting Considerations

For the reports due in March 2011, facilities reporting only emissions from stationary fuel combustion sources may use an abbreviated report format.  More information about the abbreviated reporting may be found on EPA’s fact sheet about special provisions for 2010.

It should be noted that emissions are not required to be reported by fuel type, but only in the aggregate.  At stationary combustion sources that use both fossil and biomass fuels listed in Table C-1, including biogas, the emissions from fossil fuel and biomass fuel must be reported separately.  EPA’s August 11, 2010 Federal Register notice proposed some changes to Table C-1 and the reporting of biomass emissions separately from other emissions.

EPA intends to finalize the proposed changes by the end of 2010 and NACWA will provide additional guidance on how the changes impact this provision.  In cases where emergency backup generators or mobile combustion equipment are not separately metered, operating records may be relied upon to segregate the stationary combustion sources.

The Rule stipulates that reporting may cease if annual emissions stay below 25,000 MtCO₂e for five consecutive years or below 15,000 MtCO₂e for three consecutive years.  Reporting may, of course, cease immediately if emission sources or operations are shut down.

EPA is hosting a number of web-based trainings on its electronic emissions reporting tool.  Details are available on EPA’s website.

Other Considerations

It should be noted that the categorical exemption of municipal wastewater treatment sources may only be temporary.  Appropriate emissions measurement and estimation protocols for liquid stream processes are still being debated, but many researchers acknowledge that certain processes (notably nitrification/denitrification) may generate significant N2O emissions.  As the protocols for the measurement of such emissions become more widely adopted and standardized, emissions reporting requirements may be expanded.

On July 15, 2010 (75 Fed. Reg. 41173) EPA issued a Call for Information in which it requests public comment and information from interested parties on approaches to accounting for greenhouse gas emissions from bioenergy and other biogenic sources.  GHG emissions from bioenergy and other biogenic sources are those generated during combustion or decomposition of biologically-based material, including by-products of wastewater treatment like biosolids.  While the emissions from the combustion of biogenic sources like biosolids do not currently have to be included in the reporting calculations, many groups would like to require the reporting of these emissions.  NACWA submitted comments on the proposal recommending that EPA exclude biogenic emissions from regulation under the Clean Air Act and other regulatory programs since those emissions are carbon neutral.

NACWA members should also be aware of the other benefits of developing and maintaining a GHG emissions inventory.  If and when federal climate change legislation is adopted, regulatory compliance may require facility owners to demonstrate reductions measured against a base year.  Recent bills in both the House and Senate define 2005 as a base year to measure emissions reductions.

Finally, NACWA members should be cognizant of the ability of wastewater treatment facilities to develop emissions abatement projects functioning within those facilities that qualify for financing through the development, certification and sale of emissions reduction credits in voluntary or compliance markets.  Emissions determination guidance included in the Rule may assist in identifying and assessing such opportunities.

Amendments

On September 22, 2010, EPA finalized amendments to the Rule for the mandatory reporting of greenhouse gases. Among other things, the amendments require facilities to report their corporate parent companies, applicable North American Industry Classification System codes, and whether or not reported emissions include emissions from a cogeneration unit.

Again, on August 11, 2010, EPA also proposed significant amendments to the Part 98 reporting requirements.  EPA plans to finalize the changes by the end of 2010 and NACWA will update the membership on how such changes may impact their reporting obligations.

NACWA members with questions or needing additional information should contact Cynthia Finley at This e-mail address is being protected from spambots. You need JavaScript enabled to view it or 202/296-9836.

^[1] NACWA is working to determine under what circumstances a utility may have to calculate its emissions using Tier 2.  Contact NACWA if you are having difficulty determining which tier you must use.