Agenda - Council - 10/08/2019 - Laserfiche WebLink

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Public Water Supplier: Ramsey (1020035) Date: 12/15/2017 Other high -capacity wells within 1.5 miles of the DWSMA, used in the 2007 delineation, have increased or decreased their pumping rate. In addition, some wells were not used in the previous delineation. All high capacity wells within 1.5 miles of the DWSMA were included in the new model well file and pumping rates were updated to reflect the average 2012 — 2016 pumping rates. This new well file was used in the model to estimate the new capture zone. As depicted in Figure la, the new capture zone is not very different from the old one for Wells 3, 5, 6, and 7. The pumping rates used in the delineation have increased in Well 4 and decreased in Well 8 since the previous delineation. As a result, the predicted capture zone is larger for Well 4 and smaller for Well 8. A smaller capture zone was delineated for Wells 1 and 2 (Figure lb). Wells 1 and 2 are in a separate well field east of Wells 3 through 8. They were not delineated with the model used in 2007 but were delineated using a different model under a previous plan (Robertson, 2001). Despite the differences that were noted above, the new capture zones are still contained by the existing DWSMAs (Figures la and lb). Step 4 - Using the information assembled in the previous steps, is there information documenting either 1) new hydrogeologic flow boundaries or 2) changes to the hydrogeologic flow boundaries that were included in the current WHPA delineation that are significant enough to require re -delineating the WHPA? ■ No ❑ Yes (Describe the changes to the hydrogeologic flow boundaries that have been identified. Examples include re -interpretations of aquifer geometry, hydraulic connections to surface water features or recharge.) Step 5 — Has there been a change in the ambient groundwater flow field, either due to hydrologic conditions, addition of new data or re -interpretation of old data? ■ No ▪ Yes (Describe the change.) Step 6 — Does the previous WHPA delineation need to be modified to include either or both of the following? (check as needed) ❑ Fracture flow delineation component (For example, has borehole geophysical work identified specific flow horizons in a fractured aquifer, or were secondary porosity conditions not addressed in the previous delineation according to the current standards?) ❑ Surface water contribution area (For example, has monitoring data showed that a suspected hydrologic feature is not functioning as a flow boundary or was the need for a conjunctive delineation not considered in the previous delineation?) V1.0 2/2013