1. MPCA Groundwater Monitoring and Assessment Glenn Skuta Water Monitoring Manager

2. 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.

3. 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

4. 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%

5. CEC Study Report Available
Most extensive assessment nationally or by any state.

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

7. 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

8. 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.

9. 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.

10. 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

11. 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 (so includes some remediation wells).

12. 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.

13. 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

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

15. 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