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WATER GREMLIN PUBLIC HEALTH A.SSE.S.SMENT: PUBLIC COMMENT DRAFT In July 2020, five samples were collected from Lambert Creek and the west stormwater pond (Wenck, 21121) and tested for lead and 1,4-dioxane. All haddetectable lead.. The.four samples from the. stormwater pond exceeded the SW criteria fo.r lead and ranged from 618 to 4,04.0 ppb. The samprefmm Llimbert Creek had 0.62 ppb lead. 1,4-dioxane was detected in the Lambert Creek sample at 0.35 ppb and in one of the stormwater pond samples, at 1.1 ppb. In October 20W0, M D H and MPCA staff .collected seven. surface water samples from Gem Lake, Rice Lake, and two unnamed ponds southwest of Rice Lake —all bodies of water beyond the Water Gremlin property boundaries. The samples were tested for 1,4-dioxane, which was. not detected. Figure l0: Lead in Surface Water Sampling. Results The shallow groundwater and Lambert Creek -are directly connected with one another. Based on water level observations from a monitoring. well and Lambert Creek, at.timesof high water the surface water In Lambert Creek may flow outward from the creek into the shallow groundwater. At other times the groundwater may be discharging to Lambert Creek. Infiltration of surface Water from the stormwater ponds and Lambert Creek is likely to only affect the. shallow groundwater aquifer; dye to the.presence of `the semi -confining layer between the shallow aquifer..and the buried sand aquifer. However, contaminants transported further downstream, where the semi -confining layer mey-not be present, could potentially infiltrate to deeper groundwater. 33