Mitigation

​Through the planning, environmental, and entitlement processes, a lead agency may adopt mitigation measures or conditions of approval to reduce a project’s emissions. Specific guidance on construction and operational mitigation is provided on this page. Consult the Sac Metro Air District Guide to Air Quality Assessment in Sacramento County for more details.

​Construction Emissions Mitigation

All construction projects should include Basic Construction Emission Control Practices (Best Management Practices). 

Additionally, projects with construction mitigation requirements must reduce emissions from off-road equipment.  Some projects may be required to reduce emissions from on-road haul trucks, and pay a mitigation fee. 

​Off-Road Emissions

​Enhanced Exhaust Control Practices 

NOTE:  The standard off-road equipment mitigation measures “Enhanced On-site Exhaust Controls” (April 2019) are recommended by the Sac Metro Air District for on-site emissions from construction equipment over 50 horsepower.  When on-site mitigation does not reduce emissions below the Sac Metro Air District thresholds, a mitigation fee may be included. Prior to April 2019: the previous version of Enhanced Onsite Exhaust Control Practices was in effect.

Contractors required to implement the Enhanced Exhaust Control Practices should take the following steps to ensure compliance.

​On-Road Emissions 

​For projects required to mitigate on-road haul truck emissions, use section B of the Input_Data tab of the Construction Mitigation Tool spreadsheet.  The Tool estimates on-road haul truck emissions.  See steps 2 and 4 above for submitting on-road haul truck information.

Mitigation Fees

​When a project cannot fully mitigate construction emissions by implementing off-road and on-road measures, a fee may be assessed to acheive the remaining mitigation.  Fees are adopted by the lead agency.

Currently the mitigation fee rate is $30,000 per ton of emissions (set July 2017).  Each July the rate is reviewed and adjusted if needed.  A 5% administrative fee is assessed in addition to the mitigation fee.

​Operational Emissions Mitigation

​Projects that exceed the Sac Metro Air District operational emissions thresholds for criteria air pollutants must mitigate the impacts using all feasible measures.  Sac Metro Air District staff recommends an operational Air Quality Mitigation Plan (AQMP) be developed, which describes how emissions from the project will be reduced.  The level of reductions needed for a project is determined in consultation with the lead agency and Sac Metro Air District staff.

​Greenhouse Gases

​Lead agencies also require mitigaton for project greenhouse gas emissions (GHG) that are determined to be significant.  Ideally a project will implement measures from the lead agency's Climate Action Plan (CAP) or Greenhouse Gas Reduction Plan (GHGRP) to mitigate GHG.  If no CAP or GHGRP exists, the lead agency may require a project specific GHGRP.

​Operational Mitigation Guidance

​The Recommended Guidance for Land Use Emission Reductions (Guidance) provides a description of the most current feasible mitigation measures and corresponding emission reduction potential. Project proponents should use the Guidance along with the California Emissions Estimator Model (CalEEMod) to create AQMPs and GHGRPs.

In general, the Guidance in effect at the time the Notice of Preparation was issued for a project should be used.  All versions of the Guidance are included in the table below. 

Starting February 10, 2021, Sac Metro Air District staff recommend using Version 4.3 of the Guidance.

When proponents use Guidance earlier than version 3.0, the associated Guidance for GHG Reduction document may also be used.

In some circumstances, additional mitigation measures may be necessary and can be developed using the California Air Pollution Control Officers Association's Quantifying Greenhouse Gas Mitigation Measures, A Resource for Local Government to Assess Emission Reductions from Greenhouse Gas Mitigation.

Sac Metro Air District staff is committed to working with project proponents and lead agencies to develop AQMPs and GHGRPs.  Lead agencies typically require plans to be reviewed and adequacy confirmed by the Sac Metro Air District prior to project approval.  To facilitate this, project proponents should submit draft plans for review early in the development process.

Streamlining the AQMP and GHGRP Review Process

The Sac Metro Air District provides a AQMP/GHGRP form (June 2020) to simplify the creation and review of operational AQMPs and GHGRPs. The form will reduce lead agency review time by ensuring all the necessary information is provided.

A proponent may submit the AQMP/GHGRP form in lieu of or to summarize a project's AQMP or GHGRP.  The AQMP/GHGRP form requires the input of information on topics such as: existing land use designations, public facilities and urban services financing plans, vehicle miles traveled (VMT) assumptions, energy standards assumptions, and mitigation measure enforcement mechanisms.

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