MPCA Groundwater Monitoring and Assessment Glenn Skuta Water Monitoring Manager

MPCA Groundwater Roles Monitor groundwater quality in non-agricultural parts of the state Determine groundwater-surface water interactions Evaluate groundwater protection BMPs Groundwater contamination remediation programs In the interest of time, discussing only the 1st 2 bullet points.

MPCA Groundwater Monitoring Developing a robust groundwater quality monitoring network Report on contaminants of emerging concern (CEC) in groundwater unparalleled nationally Participant in national groundwater monitoring network pilot

MPCA’S Ambient GW Network 205 wells 80 wells left to install Final number of wells in the completed network: approximately 285 The green dots show the locations of wells where good locations have been identified, and we currently are working on obtaining access agreements. The blue dots show the well locations are planned to be located and installed in FY14. Random selection stratified by land use settings. Utilizing existing wells where possible – USGS, DNR, ~35 private owners. Newly drilled ~40%

CEC Study Report Available Most extensive assessment nationally or by any state. http://www.pca.state.mn.us/index.php/view-document.html?gid=17244

Contaminants of Emerging Concern Chemicals not commonly monitored in the environment or regulated

About 100 Emerging Contaminants Antibiotics Pharmaceuticals Fire Retardants Insect Repellent (DEET) Detergent Metabolites Personal Care Products Hormones How many of the 100 are EACs? About 30

40 Wells Sampled for CECs Significance of photos? Just that we sampled wells in residentially and commercially developed areas, as well as undeveloped areas and near landfills? Yes, I just used the photos for this cue. What is the count for wells sampled by land use??? - Near Landfill = 3 Undeveloped = 3 Residential sewered =15 Residential SSTS =6 13 deep domestic wells. The water in these wells may be several decades old, and the quality of the water may not necessarily be representative of the overlying land use.

CEC Report Summary Low frequency and low levels of detection, even though wells more likely to be contaminated were targeted for this study. Emerging contaminants were present in 13 of the 40 wells monitored. Endocrine Active Compounds were detected in 3 of the 40 wells. GW affected by landfill leachate had the largest number of detections and highest total concentrations, but still well below risk levels. Further monitoring will refine this assessment. Continuing to monitor ~40 wells/yr, cycling about every 7 years. Using more robust methods that are more sensitive and scan for more chemicals.

Additional Reports Coming Soon Update to CEC report coming this summer using triple the amount of wells Overall ambient groundwater network report coming this spring Significant finding on chloride

Chloride-- Sand and Gravel Aquifers Most wells installed in the sand and gravel aquifers that had chloride concentrations exceeding the maximum contaminant level of 250 mg/L set for drinking water by the EPA were located in the Twin Cities Metropolitan Area. About 260 wells from 2007-2011 (so includes some remediation wells).

Chloride Trends The wells in South Washington County are installed in bedrock aquifers, the remainder are shallow wells in the sand and gravel aquifers. Trends were based on the period of record available, for most wells this was the mid-1990s to 2011, but the wells in the Bemidji area were sampled beginning in the late 1980s. 35 wells had sufficient data for trend analysis– criterion: at least 5 measurements over 10 years. So what conclusions do you draw from this? Almost one-third of the assessed wells showed an upward trend in chloride concentrations. In some shallow monitoring wells, chloride concentrations increased by 100 mg/L over the last 20 years. This result suggests the chloride applied in the State likely is beginning to seep downward into the groundwater.

Groundwater-Surface water Interaction Studies Investigations have linked increases in ground water extraction (municipal uses and irrigation) to stream flow reductions and lowered lake levels MPCA was the primary cooperative funder of the USGS study of altered groundwater flow affecting the level of White Bear Lake Identified reduced contribution of groundwater to surface water as a stressor in the Little Rock Creek TMDL study

Little Rock Creek – Benton Cty. Precipitation Increased pumping Decreased groundwater level Flat precipitation

Additional Groundwater-Surface Water Hydrology Research Refining groundwater recharge estimates with USGS –project will be complete in 2014 Synthetic hydrograph (streamflow estimation) project with USGS Enhancing precipitation network - automated rain gages to be installed at stream gaging stations – cooperative effort with National Weather Service and DNR