The Core Team Process: Making Risk-Informed Decisions for On-site Monitoring at the SRS

Transcription

1 The Cre Team Prcess: Making Risk-Infrmed Decisins fr On-site Mnitring at the SRS Mary A. Flra Directr, Envirnmental Cmpliance & Area Cmpletin Prjects Savannah River Nuclear Slutins, LLC January 10, 2014

2 SRS Cre Team The SRS Cre Team fcuses n making sund, cnsensus-based decisins fr all aspects f the SRS remediatin prgram, frm initial characterizatin effrts thrugh remedial selectin & implementatin t pst-clsure mnitring and maintenance. 2

3 Backgrund The Savannah River Site cleanup prgram began in 1980s under a RCRA Permit SRS was included n the Natinal Pririties List in 1989 Cleanup is cnducted t meet bth RCRA and CERCLA requirements and includes: Sils, grundwater & surface water remediatin Clsure f high level waste tanks D&D f inactive facilities EPA-4 and SCDHEC versee cleanup activities 3

4 SRS Cre Team Backgrund Established 1999 t imprve regulatry & cleanup decisinmaking prcess DOE, EPA-4, and SCDHEC Operates using the 4 Principles f Envirnmental Restratin: Benefits: #1: Building an effective Cre Team is essential #2: Clear, cncise & accurate prblem definitin are critical #3: Early identificatin f likely respnse actins is pssible, prudent, & necessary #4: Uncertainties are inherent and will always need t be managed Traceable histry f in-prcess decisin-making increases cnfidence Increased understanding f link between decisins and technical activities Clear understanding f the knwn and unknwn results in increased cnfidence that issues will be identified and managed in time Cmmunicate, Agree, Dcument! 4

5 SRS Sil & Grundwater Prgram in f 515 cntaminatin units cmpleted 68 units require pst-clsure care maintenance & mnitring 24 grundwater plumes in 14 SRS industrial areas (e.g., A, F, H, M, etc.) 39 remediatin systems ~ 2500 mnitring wells with 4100 sampling events Mature SRS grundwater mnitring prgram 5

6 Sil & Grundwater Mnitring Optimizatin Initial fcus n grundwater ptimizatin Years f grundwater data Multiple well installatin campaigns Analytes changes (types and levels) Required by Permit r Recrds f Decisin Initiated ptimizatin effrts thrugh Cre Team ER Principle #4: Uncertainties are inherent and will always need t be managed Cre Team recgnitin that mnitring needs evlve as wrk prgresses/fr varius wrk stages Cmmunicate, Agree, Dcument! M Area Pint f Cmpliance Wells 6

7 Objectives Optimize (right-size) grundwater mnitring Evaluate grundwater units individually t ensure discrete prgress and sund, defensible decisins Maintain regulatry cmpliant, envirnmentally prtective, and technically rbust mnitring system Benefits: Obtain needed data vs redundant, superfluus, pr quality r insufficient data Reduce demands n samplers, analytical labs, data management & reprting persnnel AND Regulatrs t reduce verall prgram csts 7

8 Optimizatin Decisin Lgic Cre Team agreed t evaluate: 1. Current Mnitring vs. Regulatry Requirements 2. Spatial Optimizatin 3. Tempral Assessment 4. Analyte Assessment 5. Reprting Assessment (frequency) Technically-based evaluatins Dcument decisins thrugh regulatry dcuments, including Permits, RODs, and reprts & plans 8

9 #1. Cmpare Current Mnitring t Requirements Evaluated mnitring & reprting requirements specified in RCRA Permit, RODs, and RCRA Burden Reductin Initiative Fund mst units cnsistent with requirements Eliminated analytes fr sme units Changed submittal f regulatry reprts frm semi-annually t annually fr 2 RCRA units 9

10 #2. Example f Spatial Optimizatin SRS technically evaluated existing mnitring well netwrk fr individual units (e.g., R-Area) t determine if well netwrk prvided infrmatin required t meet regulatry requirements, ensure apprpriate infrmatin is being gathered and wells are lcated ptimally. Presented evaluatin results t Regulatrs & discussed Mdified regulatry dcuments, as needed, and implemented changes 10

11 #2. Spatial Optimizatin Spatial Optimizatin Evaluatin Fr each aquifer unit, cnsider the fllwing (r ther) questins: Are surce/intermediate well(s) prviding unique data regarding the seepage basin surce; lcated at histric maximum cncentratin lcatins? Are plume bundary wells demnstrating that the plume is nt expanding, and is cnsistent with mdel predictins? Are auxiliary wells prviding trending infrmatin n key cntaminants, r are they spatially redundant? Is plume vertically bunded? Are wells fcused n high cncentratin znes and predicted znes f breakthrugh? 2012 Results SRS identified spatial ptimizatin as fllws: 9 f 18 units assessed have wells recmmended fr discntinued sampling due t spatial redundancy 4 f 18 units assessed have wells recmmended fr additin due t spatial data gaps SRS prpsed and gained regulatr cncurrence t the fllwing: Discntinue sampling f 72 wells Incrprate data frm 9 existing wells int the mnitring netwrk Install 7 new wells t add t the mnitring netwrk 11

12 #3. Example f Tempral Optimizatin f Mnitring Wells Evaluate fr stable r decreasing trends with limited variability ver time? 12

13 #3. Tempral Assessment Tempral Assessment Evaluatin Fr each subset f mnitring wells, cnsider the fllwing (r ther) questins: D surce well(s) prvide data at a frequency adequate t detect a release? D plume bundary wells prvide data at a frequency adequate t demnstrate the plume is nt expanding, crssing LUC bundary, r discharging t surface water, and is cnsistent with mdel predictins? D intermediate plume wells prvide trending infrmatin n key cntaminants cnsidering rate f change expected based n transprt velcities? Are effects f active remediatin mnitred at frequency t detect significant changes? Is mnitring frequency cnsistent with expected remedy timeframe (e.g. MNA t take 50+ years, biennial sampling f intermediate plume wells adequate)? 2012 Results SRS identified tempral ptimizatin, as fllws: 15 f 18 units have wells recmmended fr reduced frequency f sampling 1 f 18 units assessed has wells recmmended fr increased frequency f sampling & mnitring due t tempral data gaps SRS prpsed and gained regulatr cncurrence t the fllwing: Reduce sampling frequency fr a ttal f 346 wells. Increase sampling frequency fr a ttal f 42 wells (primarily water levels fr wells lcated arund an perating air stripper that is being evaluated fr shutdwn) 13

14 #4. Analyte Assessment Analyte Assessment Fr each analyte, cnsider the fllwing (r ther) questins: What is the regulatry driver (e.g. cntaminant f cncern [> MCL], crrective actin cnstituent, mnitring cnstituent [> backgrund cncentratins], gechemical indicatr [ph, ethene,etc.]? D reprting requirements (i.e., 5-Year ROD Review) require cntinued analysis? Can a class f cntaminants (e.g. metals) be eliminated? Can ther cntaminants be used as a bunding case cnsidering the spatial extent and cncentratin level? What is the frequency f detectin abve the limit (r at all) in a given well r netwrk? Des trend analysis acrss plume supprt future predictins that analyte will n lnger prvide useful data t supprt remedy r decisin-making? 2012 Results SRS identified tempral ptimizatin, as fllws: 3 f 18 units have analytes recmmended t be discntinued 3 f 18 units have analytes recmmended t be added t sampling & mnitring regimen SRS prpsed and gained regulatr cncurrence t the fllwing: Reduce analytes assessment fr a ttal f 363 wells. Added analytes t be assessed at a ttal f 75 wells (Nte: f these 75 wells, 65 wells were added t assess 1,4-dixane) 14

15 #5. Reprting Assessment Reprting Assessment Fr each reprt, cnsider the fllwing (r ther) questins: Can a subset f wells be utilized fr time trends? Can statistical analysis be eliminated r pstpned? Can a subset f plume maps be representative? Can units be cmbined? Can map scale be mdified fr ease f use? 2012 Results SRS identified tempral ptimizatin, as fllws: 6 f 18 units have requests t reduce reprting frequency recmmended t be discntinued Majr cntent mdificatin recmmended fr 1 f 18 units due t cmpletin f remediatin and shutdwn f remediatin system SRS prpsed and gained regulatr cncurrence t these recmmendatins fr reprting imprvements 15

16 Optimizatin Results and Summary Early & frequent Cre Team deliberatins ensured prcess was successful and all parties agreed Expanded t included remediatin systems Technical evaluatins were basis fr all evaluatins, recmmendatins & decisins Decisins were dcumented Cre Team ptimizatin prcess accepted as standard prcess and cntinuing QUESTIONS? 16