Delivering sustainable solutions in a more competitive world Managing Your Groundwater Program - Do’s and Don’ts Matthew Daly, P.G RETS-REMP Philadelphia, PA

Delivering sustainable solutions in a more competitive world Groundwater Programs Non-nuclear – thousands of sites over the past 30 years Gas stations and bulk terminals Dry cleaners Manufacturing facilities Landfills Myriad of contaminants and site conditions NAPLs, solvents, metals, PAHs…. Sand, silt, clay, fractured bedrock, sediment and surface water Well depths from 15 to 300+ feet Sampling methods, frequency and parameters

Delivering sustainable solutions in a more competitive world Groundwater Programs – cont’d Lessons learned can help to streamline and maximize effectiveness of groundwater programs at nuclear power plants Planning with the end in mind – REMP

Delivering sustainable solutions in a more competitive world The Six Components of Effective Groundwater Monitoring Programs Implement Phased Field Investigation (4) Assemble Project Team (1) Identify Sources, Receptors and Plant Influences (2) Implement Monitoring Program (5) Groundwater Monitoring Program Develop & Refine Initial Conceptual Model (3) Calculate Tritium Flux Component (6)

Delivering sustainable solutions in a more competitive world Assemble Project Team Plant Operations Health Physicists & Engineers Geologists Hydro- geologists Field Technicians/ Specialists Subcontractors Drilling & Laboratory Data Validation & Management Specialists External Stakeholder Interests Corporate Use Internal and External Resources

Delivering sustainable solutions in a more competitive world Identify Sources Identify known or potential sources of liquid release to groundwater, e.g., Spent Fuel Pool, piping, sumps, tanks, spills, etc. Tritium most common, but Cobalt-60, Cesium-137 and Strontium-90 also found. Consider hierarchy of potential sources based on magnitude, age, duration, exposure potential to receptors and logistics of investigation.

Delivering sustainable solutions in a more competitive world Identify Sources – cont’d Source Identification – Continue to evaluate throughout program to identify, control and eliminate where feasible. Evaluation of Systems and Components Evaluation of Procedures and Past Practices Evaluation of Available Groundwater Monitoring Results

Delivering sustainable solutions in a more competitive world Identify Receptors Groundwater Usage Survey Springs Surface water On-site and off-site water supply wells Receptor Analysis – Early in program to reinforce lack of risk posed and build stakeholder confidence

Delivering sustainable solutions in a more competitive world Sources & Receptors – Use Existing Data FSAR & USAR geologic and hydrogeologic reports Plant drawings and construction diagrams 50.75(g) Files Locate, inventory and sample existing wells REMP program

Delivering sustainable solutions in a more competitive world Develop Conceptual Site Model

Delivering sustainable solutions in a more competitive world Refine Conceptual Site Model

Delivering sustainable solutions in a more competitive world Implement Phased Field Investigations Design site assessment program to achieve project goal(s) Characterize site geology and hydrogeology to the extent necessary How do they affect contaminant distribution, migration and attenuation Define contamination source, nature and extent Don’t exacerbate site conditions – work from “outside-in, top-down”

Delivering sustainable solutions in a more competitive world Drilling Techniques

Delivering sustainable solutions in a more competitive world Drilling Technologies Unit Cost / well Investigation Depth Degree of Conservatism Geoprobe Hollow Stem Auger Telescope Casing Rotosonic

Delivering sustainable solutions in a more competitive world Overburden Investigation Tools Cost Qualitative Multilevel wells Cone Penetrometer Soil borings Monitoring Wells Waterloo Profiler Quantitative

Delivering sustainable solutions in a more competitive world Bedrock Investigation Tools Cost Qualitative Multilevel wells Surface geophysics Borehole geophysics Pumping Tests Rock coring Long open boreholes Transducers Packer Tests Quantitative FLUTe Air rotary

Delivering sustainable solutions in a more competitive world Elevation (ft) Oxidation/Reduction Potential (mV) Dissolved Oxygen (mg/L) pH Specific Conductance (uS/cm) Hydraulic Head (feet) Index of Hydraulic Conductivity (unitless) Elevation (ft) Heterogeneity – Variability of Subsurface Aquifers

Delivering sustainable solutions in a more competitive world Data Representativeness

Delivering sustainable solutions in a more competitive world Aquifer Testing – Determine Groundwater Flow Rate Hydraulic conductivity (K) Field test to “stress” a well and monitor response in the groundwater level Examples include slug, pumping and tracer tests Need to consider scale effects

Delivering sustainable solutions in a more competitive world Aquifer Testing – Tools for Determining K Cost Slug Test Pumping Test Tracer Test Degree of Certainty in K value Volume of Aquifer Tested

Delivering sustainable solutions in a more competitive world Implement Monitoring Program Select groundwater sampling method(s) Select analytical parameters Implement quality assurance/control program

Delivering sustainable solutions in a more competitive world Groundwater Sampling Methods Various techniques Bailer, thief, grab, diffusion bag, low-flow Low yield wells need special attention Low-flow considered most robust for obtaining representative groundwater samples (EPA, State and EPRI Draft Guidance)

Delivering sustainable solutions in a more competitive world Cost Thief Grab Low-flow Diffusion Bags 3-well volumes Representativeness Groundwater Sampling – Methods

Delivering sustainable solutions in a more competitive world Low-Flow Groundwater Sampling Stabilization Parameters: Temperature Conductance pH Redox Potential Dissolved Oxygen Turbidity Water Level

Delivering sustainable solutions in a more competitive world Selection of Analytical Parameters Radiological Tritium Gamma Hard to Detects? Non-radiological? VOCs (solvents) PAH (fuels, oils)

Delivering sustainable solutions in a more competitive world Consider Monitoring Frequency

Delivering sustainable solutions in a more competitive world Implement QA/QC Program Laboratory Quality Control Issues Verify appropriate and consistent Lower Limits of Detection Need to consider site-specific background levels Need to consider State and Federal reporting levels Reporting units (pCi/L versus  Ci/ml) Third party analysis of duplicate samples

Delivering sustainable solutions in a more competitive world Implement QA/QC Program – cont’d Field Quality Control Methods Duplicate/Blind Samples Matrix Spike & Matrix Spike Duplicate Equipment Blanks (Decontamination) Performance Evaluation Samples

Delivering sustainable solutions in a more competitive world Tritium Flux Component What is it? How many curies of tritium are being discharged through groundwater Why calculate? Account for released tritium to groundwater as part of ODC How to calculate? 1 st Approximation Method – combine Darcy’s Law for groundwater flow and concentration data from sample results Calibrated groundwater flow model

Delivering sustainable solutions in a more competitive world Tritium Flux Component – cont’d Groundwater Discharge (Q) using Darcy’s Law: Q = groundwater discharge rate within plume [Liters/day]; K = hydraulic conductivity from aquifer test [m/day]; A = cross sectional area perpendicular to groundwater flow and plume [m 2 ]; and dh/dl = hydraulic gradient calculated from wells [unit-less].

Delivering sustainable solutions in a more competitive world Tritium Flux Component – cont’d Tritium Flux [  Ci/day] = Concentration x Groundwater Flow Rate Concentration [pCi/L] – groundwater monitoring results Groundwater Flow Rate [L/day] – Darcy’s Law Apply unit conversions for  Ci/day Calculate tritium flux over REMP reporting period (quarterly, annually, etc.) for  Ci released

Delivering sustainable solutions in a more competitive world Pitfalls to Avoid Don’t treat all sites as equal Don’t assume plumes are static (new releases, seasonal effects) Don’t just look shallow – releases can occur below the water table (plant construction and geology) Don’t drill deep in a potential source area unless rigorous controls are in place (cross- contamination) Don’t expect all answers to questions after one round of investigation and sampling (phased approach)

Delivering sustainable solutions in a more competitive world Low-Flow Sampling - References Puls, R.W., and Barcelona, M.J., April 1996, “Low-Flow (Minimal Drawdown) Ground-Water Sampling Procedures”. EPA Ground Water Issue. EPA/540/S- 95/504. U.S. Environmental Protection Agency, July 30, “Low Stress (low flow) Purging and Sampling Procedure for the Collection of Ground Water Samples from Monitoring Wells”. Region I. SOP #: GW U.S. Environmental Protection Agency, May “Ground-Water Sampling, Guidelines for Superfund and RCRA Project Managers” stagnant water removal procedure. Yeskis, D., and Zavala, B., May “Ground-Water Sampling Guidelines for Superfund and RCRA Project Managers”. Ground Water Forum Issue Paper. EPA 542-S

Delivering sustainable solutions in a more competitive world Questions?