Minnesota Pollution Control Agency

About: Minnesota Pollution Control Agency is a government organization based out in Saint Paul, Minnesota, United States. It is known for research contribution in the topics: Stormwater & Sulfate. The organization has 154 authors who have published 214 publications receiving 7820 citations.

Drivers of change for lakewater clarity

Abstract: Baker, L.A., J.E. Schussler and S.A. Snyder. 2008. Drivers of change of lake clarity. Lake Reserv. Manage. 24:30–40. Lakes in the Upper Midwest have undergone extensive lakeshore development over the past 30 years, raising concerns about eutrophication. We examined 11 case study lakes in Minnesota that had undergone substantial shoreline development over the past 30 years to evaluate drivers of change in clarity. Relationships between current Secchi disk transparency (SDT) and the density of permanent equivalent houses (PEHs) and between change in SDT and change in density of PEHs were not statistically significant. For lakes with large watershed area-to-lake area (WSA: LA) ratios, modeled worst-case scenarios for impacts of shoreline housing show that phosphorus (P) inputs may not be sufficient to reduce SDT. For sensitive lakes, improved P management policies may counteract increased shoreline development, at least in part. For lakes with large WSA:LA ratios, activity outside the shoreline area, particularly agricultural activity, is probably more important than shoreline development in affecting SDT. Although policies considered “lake management” operate at fairly small scales, drivers of change in SDT operate at various temporal and spatial scales, from household to global.

Survivorship and longevity of Diamesa mendotae Muttkowski (Diptera: Chironomidae) under snow

Abstract: Diamesa mendotae Muttkowski commonly grow and emerge from groundwater dominated streams in winter. Previous estimates of longevity for adults of D. mendotae collected from the snow surface averaged 18.6 days post-collection, with 76.9% of individuals dying between Day 10 and Day 30 post-collection and 4.4% surviving over 40 days. Maximum longevities for males and females were 48 and 54 days, respectively. In this paper, we report survivorship and longevity of fieldcollected adults of D. mendotae kept at ambient snow temperature conditions. Adults (n=140) were collected in February from snow along groundwater-dominated sections of the Kinnickinnic River (Wisconsin, USA). All individuals were placed in vials, buried in snow, and retrieved in batches of 10 males and 10 females at 4-day intervals for 28 days. Once retrieved, adults were maintained at 6°C in controlled environmental chambers to determine survivorship and longevity. All individuals survived snow burial treatment, indicating they are capable of surviving sub-freezing field conditions for at least 28 days. Estimates of adult maximum longevity were as high as 66 days, higher than previous estimates for this genus. Our results suggest adults of D. mendotae can persist under snow cover, with high survivorship and longevity, potentially increasing their probability of successful reproduction in regions where lethal winter air temperatures occur.

Laboratory Comparison of Field Infiltrometers

Abstract: Three devices for measuring hydraulic conductivity of soil in the field were tested under controlled conditions in the laboratory using three types of media to compare their accuracy and pr...

Drainage and nutrient attenuation in a riparian interception-wetland: southern Minnesota, USA

Abstract: Riparian wetlands have multiple source waters that require understanding to effectively manage water quantity and quality. Source waters were determined in an interception-wetland located a relatively flat clayey till terrain in southern Minnesota. Data loggers were used to measure precipitation, water stage from monitoring wells and a tile-drain outlet. Over 70 oxygen (δ18O), hydrogen (δD) and geochemical water samples were collected from seven locations over different seasons (9 events) from 1996 to 1999. Results indicate the dominant source water input to the wetland was drained shallow groundwater beneath intensively managed cropland (P = 0.000). Evapotranspiration was the dominant export pathway. Nitrate–nitrogen (NO3-N) concentrations significantly decreased (P = 0.000) in the cattail-willow portion of the wetland. Total phosphorous (TP) concentrations were relatively high in the grass portion of the wetland (673 ± 549 μg L−1), and relatively low in the cattail-willow portion of the wetland (139 ± 85 μg L−1) because source waters were low in TP. Overall, the interception-wetland design limited out-of-bank flooding, yet allowed sufficient gradient between the cropland and the wetland outlet to minimize potential crop damage and provide hydraulic storage for nutrient attenuation.

Low Levels of Sodium and Potassium in the Water from Wetlands in Minnesota that Contained Malformed Frogs Affect the Rate of Xenopus Development

Abstract: Water samples were collected between 1999 and 2000 from wetlands in Minnesota that contained malformed frogs. The water samples were analyzed for 14 minerals/ions and screened for the presence of biologically active compounds using Xenopus laevis. Results indicated that water from two sites, CWB and ROI2, induced severe retardation with embryo lengths reduced 20% after 96 hr of development. The developmental delay observed with water from ROI2 was alleviated by supplementation with sodium, while both sodium and potassium alleviated the developmental delay observed with water whose mineral content mimicked that of CWB. Seasonal fluctuations in the sodium and potassium content at ROI2 and NEY correlated with changes in the rates of Xenopus development. Xenopus embryos reared on water from ROI2 for 120 hr displayed gut malformations not present in embryos reared on a synthetic media designed to mimic the mineral content of the water from ROI2. Embryos reared on water from ROI2 supplemented with minerals at levels comparable to that routinely employed in the rearing of Xenopus were neither retarded nor malformed. It is proposed that climate driven hydrology may influence the mineral composition at selected wetlands and delay development which may alter window(s) of susceptibility towards biologically active agents and the occurrence of malformed frogs.