1. www.energy.gov/EM 1 Aggregate Areas David S. Rhodes Acquisition Integrated Project Team Chair Environmental Management Los Alamos Field Office March 3, 2015

2. www.energy.gov/EM 2 Division of Drainages  Plateau dissected by nineteen major surface drainages or canyons and their tributaries running roughly west to east or southeast and drain into the Rio Grande  Many drainages large enough to split into sub-areas: upper/middle/lower  Thirty aggregate areas (AA) identified in Consent Order Ten AAs completely investigated Ten AAs in-progress with partial investigations and some cleanup work Ten AAs not yet investigated (no cleans conducted)

3. www.energy.gov/EM 3 Pajarito Plateau

4. www.energy.gov/EM 4 RCRA Process  Investigation Work Plan (IWP) IWP to NMED for plan approval  Field characterization activities Field Screening Sampling to off-site analytical laboratories  Field cleanup of sites above soil screening levels Cleanup while crews in field  Identify constituents of potential concern (COPC)  Risk assessment of results Identification for cleanup of site with risk above thresholds  Investigation Report (IR)

5. www.energy.gov/EM 5 In-progress examples  Historical Townsites Private property sites provide access to remaining canyon-side sites Los Alamos County property containing wetlands and sites Commercial development sites provides access to remaining canyon-side sites  Upper Los Alamos Canyon Former sites’ stack discharge locations/outfalls into canyon Heaviest discharges of uranium and plutonium contaminants Lead-contaminated soils beneath bridge  Middle Los Alamos Canyon Outfall sediment reaches  Lower Los Alamos Canyon Sediment reaches and canyon bottom areas of concern (AOC) Sediment transport mitigations

6. www.energy.gov/EM 6 In-progress cleanup pics PCB contaminated soil removal TA-61 North Ancho Remediation Sandia Canyon Wetland Stabilization Spider Excavator on Canyon Edge

7. www.energy.gov/EM 7 Supplemental Investigation Reports  Ongoing effort to update Supplemental Investigation Reports (SIRs) with a Risk Assessment addendum Five SIRs in FY2015 Two submitted to NMED – no comments received on SIRs Preparing three more Six SIRs in FY2016 Dependent on funding and priority Likely will slide 2-3 into FY2017 Could result in hundreds of certificates of completion (CoC) without additional cleanups

8. www.energy.gov/EM 8 Specific site cleanups  19 sites identified as above soil screening levels from previous investigations  Additional sites are expected to exceed soil screening levels and will need to be cleaned It is anticipated that these additional sites will be generally consistent from aggregate area to aggregate area, including: Leaking septic system piping Leaking small laboratory drain lines  Document specific site cleanups in investigation reports Should lead directly to CoC

9. www.energy.gov/EM 9 Complete remaining investigations  Review of historical investigation information (pre-Consent Order)  Some have IWPs; others do not Develop and submit to NMED for approval Leave latitude to go back into field to close gaps without having to request permission (work-at-risk)  Contract or conduct field sampling activities Field screening important to close gaps Did we go wide enough or deep enough? Conduct field cleanups as investigation progresses  Assess risk of resulting/remaining contaminants  Document in investigation reports