Thanks to funding from the Northwest Biosolids Association, NEBRA updated and released a new version of the Biosolids Emissions Assessment Model (BEAM) at the end of 2024. The BEAM is a spreadsheet that accounts for carbon emissions (carbon dioxide, methane, and nitrous oxide) and credits (or sinks) from wastewater sludge processing through disposal and end use. The updates follow a review by the Science Review Team (SRT), five PhDs with various areas of expertise related to the BEAM. The 2024 BEAM has updated emission factors and allows for more customization to account for particular sludges, locales, and situations being modeled. The heart of the BEAM is the References, Calculations, Assumptions and Default Values tab. You can download the BEAM at www.BiosolidsGHGs.org where you will find the Users Guide and other resources.

 Some of the improvements, including those recommended by the SRT, include:

  • updated and reframed carbon sequestration rates options for land-applied biomass to accommodate the range of possible carbon sequestration rates that occurs due to site characteristics and site management

  • updated parameters for composting

  • updated methane oxidation calculations for the landfill scenarios

  • updated methane emissions calculations from combustion sources

  • updated regional electricity carbon footprint values from Emissions & Generation Resource Integrated Database (eGRID)

  • added fugitive methane emissions during the de-watering process for undigested biomass

  • flexibility to input climate data (number of days per year over 15oC) on the Storage tab

  • improved accounting for fertilizer offset credits

  • improved spreadsheet layout; more user defined options

All this work was made possible by a $25,000 grant from Northwest Biosolids Association and major in-kind technical services by Northern Tilth (Belfast, Maine). NEBRA has been spreading the word about the new BEAM in presentations and papers. The BEAM is managed by NEBRA’s BEAM Team, a subgroup of members from the Carbon Trading Committee. The April edition of the Water Environment & Technology magazine will have an article by members of the BEAM Team. There will also be a Lunch & Learn (https://us06web.zoom.us/webinar/register/WN_18FNykXtQ6K1vXunsDcGCQ) about the New BEAM on May 23rd.