Sediment Studies: Twin Cities and Statewide Sediment Investigations

Sampling sediment in a stormwater pond

2017 National Lakes Assessment: Sediment Data from Minnesota (in progress)

Project description: The National Lakes Assessment (NLA) is a randomized statistical survey conducted by the U.S. EPA and its partners every five years to determine the condition of our nation’s lakes, ponds, and reservoirs. For the 2017 NLA survey, surficial sediments (i.e., 0-5 cm) were added as a new component of this study.

In Minnesota, 50 lakes will be sampled by September 2017. One composite sediment sample from each lake will be analyzed for particle size, total organic carbon (TOC), 16 metals and metalloids, 21 polychlorinated biphenyl (PCB) congeners, 25 polycyclic aromatic hydrocarbons (PAHs), and 27 organochlorine pesticides and metabolites. The U.S. EPA will evaluate the national sediment chemistry data set. The MPCA anticipates using the Minnesota sediment chemistry data set to update the background threshold values from a 2007 statewide sediment survey (Crane 2017) and to make further comparisons to watershed land uses.

For further information: Mari Nord (U.S. EPA Region 5), 312-886-3017 and Judy Crane, 651-757-2293.

Emerging Contaminants in 30 NLA Lake Sediments (in progress)

Project description: The MPCA funded a “value-added” project to Minnesota’s component of the 2017 NLA survey. Extra surficial sediment was collected, composited, and split from the U.S. EPA’s sediment samples for the analysis of emerging contaminants. Thirty of the 50 NLA lakes sampled in Minnesota were targeted for this study. AXYS Analytical Services Ltd. will analyze these sediment samples for pyrethroids, pyrethrins, piperonyl butoxide, alkylphenols, and alkylphenol ethoxylates. The results will be used in 2018 to determine the spatial extent of these contaminants. In addition, the data will be evaluated in the context of watershed land uses, potential aquatic life impairments, and development of background threshold values for parameters with < 80% nondetects.

For further information: Judy Crane, 651-757-2293.

Influence of Sources and Land Uses on the Distribution of PAHs and Other Contaminants in Urban Stormwater Pond Sediments (in progress)

Project description: The MPCA collected surficial sediment samples from fifteen stormwater ponds in the Minneapolis-St. Paul metropolitan area during October 2009 in support of coal tar legislation enacted into law in Minnesota during May 2009. Five ponds from each of the following major landscape categories were sampled: residential, commercial, and industrial land uses. Sediment samples were collected from the upper 15 cm of the sediment profile using a drop corer from three sites within each pond. A subsample from each site was composited together for a separate composite sample. Thus four sediment samples were obtained from each pond. All samples were analyzed for a suite of 18 metals and metalloids, mercury, carcinogenic PAHs, TOC, black carbon, and particle size. In addition, laser induced fluorescence was used as a screening tool for PAHs on all samples. The composite samples were analyzed for chloride, semivolatile organic compounds, 34 parent and alkylated PAHs, and several emerging contaminants, including: per- and polyfluoroalkyl substances (PFASs), polybrominated diphenyl ethers (PBDEs), pyrethroids, nonylphenols, nonylphenol ethoxylates, and octylphenols. The data were analyzed to assess sources of PAHs, to evaluate screening methods for PAHs, and to determine the influence of urban watershed land uses on contaminant concentrations.

For further information: Judy Crane, 651-757-2293.

Completed papers from this study and related work on PAHs and coal tar-based sealants

Statewide Endocrine-Disrupting Chemicals Study

Project description:  This study was funded by the Minnesota Legislature in 2007 to advance work already accomplished in this area by the MPCA, the U.S. Geological Survey, and St. Cloud State University. This collaborative team also worked on this study. Field work began in April 2008 and included a total of 20 lake, stream, and river locations. Surface water samples were analyzed for alkylphenols, alkylphenol ethoxylates, hormones, and pesticides. Sediments were analyzed for antibiotics, nonsteroidal anti-inflammatory drugs, musks, alkylphenols, hormones, organic wastewater compounds, and pesticides. Fish tissues were analyzed for evidence of endocrine disruption at each site.

For further information: Mark Ferrey, 651-757-2355.

Completed papers from this study

North Central Lakes Sediment Core Project

Project Description: The St. Croix Watershed Research Station, a division of the Science Museum of Minnesota, conducted this project for the MPCA. The study focused on eight lakes in northwest Minnesota that are impaired for excess nutrients. Sediment cores were analyzed for parameters to track lake conditions back to the pre-settlement period. The information obtained from this study will be used to conduct total maximum daily load (TMDL) studies.

For further information: Tim James, 218-846-8103.

Completed paper from this study

Alkylphenols, Other Endocrine-Active Chemicals, and Fish Responses in Three Streams in Minnesota — Study Design and Data

Project description:  The MPCA, U.S. Geological Survey, and St. Cloud State University collaborated on this Phase 3 project to examine nonpoint sources, fate, and persistence of alkylphenols in smaller streams in Minnesota. Effluent, water, and sediment samples were collected upstream and at two points downstream of three wastewater treatment plants (Hinckley, Hutchinson, and Marshall) from February to September 2007. Other organic wastewater compounds were analyzed in two rounds of water and effluent samples. A biological assessment was conducted at each site, as well.

For further information about the study results, see the U.S. Geological Survey website, or contact Angela Preimesberger at 651-757-2656.

Completed papers from this study

Assessment of Chemicals of Potential Concern in Minnesota Lake Sediments and Fish Tissues

Project description: This project provided the first ever, overarching assessment of ambient sediment quality conditions in Minnesota. A stratified random sampling plan was used to sample 50 lakes during the summer of 2007. In addition, surficial sediments from four potential reference lakes were collected, as well. The analyte list included: 19 metals and metalloids, 43 PAHs, biphenyl, congener-specific PCBs, organochlorine pesticides, PBDEs, dioxins and furans, TOC, and particle size. Three trophic classes of fish from five of the lakes were analyzed for PBDEs.

The sediment samples were used to provide an indication of the statistical range of more recently deposited analytes and to determine if these concentrations were influenced by major watershed land uses. In addition, sediment quality in each lake was evaluated and sources of PAHs were determined. The results of the fish survey were used to determine differences in contaminant uptake between trophic groups.

For further information: Judy Crane, 651-757-2293.

Completed papers from this study

Assessment of Nonpoint Pollution through the Analysis of Sediment Cores from 55 Minnesota Lakes (multi-agency project)

Project description: This project documented geographic and historic trends in lake eutrophication, as well as nonpoint inputs of toxic metals and organic pollutants to 55 Minnesota lakes. Land-use impacts were separated from atmospheric sources in this study. Sediment cores were collected from each lake, with subsequent time period dating with lead-210. GIS analysis of each lake's watershed was done to determine local land use. The sediment samples were used to assess the history of lake eutrophication (through diatom analysis) and to quantify inputs of toxic chemicals (mercury, dioxins, furans, PCBs, chlorinated pesticides and heavy metals).

For more information: Ed Swain, 651-757-2772

Completed papers from this project