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Concurrent Sessions - Session I

SESSION I.
Management Approaches for Sustainable Urban Streams

Some PowerPoint presentations are available for download. Please click on session presentation titles below to access the download link.

Session Chairs:
Don Witherill, Maine Department of Environmental Protection
Phil Ruck, Stillwater Environmental Engineering, Inc.

Description:

This session will focus on non-point source pollution in urban streams and how smart growth strategies can help alleviate these issues. Presentations may include talks on key contaminants occurring in Maine’s urban streams such as chloride from winter salt application, coal tar sealants used on parking areas, driveways and other surfaces, and the effects of impervious cover on stream health. Presentations that discuss smart growth strategies that link economic development and community well-being to the stewardship and health of the environment will also be accepted especially those which advance the restoration of urban waters by improving water quality in urban areas.

Session Presentations:

Management Approaches for Sustainable Urban Streams: Part I

Management Approaches for Sustainable Urban Streams: Part II

Abstracts:

Stormwater Utilities as a sustainability management tool: every community will want one
PowerPoint presentation available for download.

Steve Kahl

James Sewall Company, Old Town, ME; Steve.kahl@sewall.com

A stormwater utility (SWU) is a utility that collects fees to pay for stormwater management. The fees are based on the impervious area of properties because imperviousness generates stormwater. Rather than putting the full burden of stormwater management on property taxpayers, stormwater utility fees are assessed across all developed properties, a fundamental fairness advantage for SWU. Landowners can opt out of the fee if they mitigate imperviousness and thereby reduce stormwater runoff, a win-win-win for the property owner, the municipal DPW, and local water quality in urban streams. Cash-strapped municipalities like stormwater utilities because of the need for revenue and the predictability of the revenue stream long-term. Interest in stormwater utilities in New England is increasing. There are over 4,000 stormwater utilities nationally, so the upside for their creation in New England is substantial because we only have a half dozen operating here.

The Role of Citizen Scientists in the Restoration of Trout Brook
PowerPoint presentation available for download.

Tom Mikulka1, Kate McDonald2, Fred Dillon3

  1. Citizen scientist, Cape Elizabeth, ME; mikulka.tom@gmail.com
  2. Cumberland County Soil & Water Conservation District, Windham, ME; kmcdonald@cumberlandswcd.org
  3. South Portland Water Resource Protection Department, South Portland, ME; fdillon@southportland.org

The Maine Department of Environmental Protection (DEP) has designated 31 streams throughout the state as “urban impaired” for failure to meet water quality standards due to adverse impacts from surrounding development. Trout Brook, which flows through Cape Elizabeth and South Portland before emptying into Casco Bay, is one such urban impaired stream. In 2012, the City of South Portland used an Environmental Protection Agency (EPA) grant to develop a Watershed Management Plan (WMP). The WMP recommends several strategies to restore Trout Brook’s water quality and aquatic habitat and establishes a monitoring program to formalize water quality sampling activities. An innovative aspect of the monitoring program is its reliance on macroinvertebrate data collected by citizen scientists to help determine the relative effectiveness of ongoing restoration efforts.

 
More recently, South Portland and Cape Elizabeth received additional EPA grant funds to implement restoration strategies identified in the Trout Brook WMP. Therefore, it will be critically important to build upon the water quality monitoring data the City has collected over the past several years and establish pre-implementation conditions. South Portland, CCSWCD and DEP staff have collaborated with local citizen scientists and high school students to pilot a simplified macroinvertebrate monitoring program adapted from Wisconsin’s Citizen-Based Water Monitoring Network protocols. While the results from these efforts cannot be used for regulatory compliance purposes, identifying changes in macroinvertebrate populations can help determine whether restoration activities are improving aquatic habitats. Preliminary results from the fall of 2013 suggest that this approach will be a successful screening tool.

The ability of streams to withstand the effects of urbanization
PowerPoint presentation available for download.

 Tom Danielson, Leon Tsomides, Doug Suitor

Maine Department of Environmental Protection, Augusta, ME; thomas.j.danielson@maine.gov

The Biological Monitoring Program completed its study of the effects of impervious cover (IC) in watersheds on Maine’s stream algae and macroinvertebrates.  The risk of not attaining Class AA/A biological criteria increases in the range of 1-3% IC.  Between 3-6% IC, there is an increased risk of not attaining Class B biological criteria.  Finally, there is an increased risk of not attaining Class C biological criteria in the range of 10-15% IC.  Location of IC in a watershed matters.  In general, watersheds with development close to the streams had poorer quality macroinvertebrate communities than streams with intact riparian corridors.  Although IC is commonly used as a surrogate for urban development, IC is only one of many factors that influence urban stream condition.  In addition to IC, stream quality is determined by the condition of riparian corridors, flood plains, in-stream habitat, stream bank stability, water flow, water temperature, habitat fragmentation or isolation, specific conductance, nutrient enrichment, and toxic chemicals.  IC can influence many of the factors listed above, but natural conditions and non-IC stressors also influence the factors listed above and ultimately determine how resilient a stream is to IC.  A stream may be more resilient if the other factors are favorable to healthy aquatic communities.  In contrast, some streams may be more susceptible to IC if the other factors are not favorable to healthy aquatic communities.  In general, resource managers should be cautious about focusing watershed protection and restoration plans only on IC. 

Adverse Impacts on Groundwater Quality and Conflicts with Existing and Designated Uses Resulting from Stormwater Infiltration

John Hopeck and Mark Holden

Bureau of Land and Water Quality, Maine Department of Environmental Protection, Augusta, ME

 Stormwater infiltration is a commonly recommended LID practice and is assumed to minimize impacts on surface waters and provide for maintenance of baseflow. However, locations suitable for infiltration of large volumes of stormwater are severely limited by the geologic characteristics of the sites and by other uses of these areas. Data from sites regulated by Maine DEP and in other jurisdictions indicate substantial impairment of groundwater quality and baseflow discharges in areas downgradient of infiltration facilities, apparently resulting from both the stormwater infiltration and geochemical changes within the infiltration structures. Contaminants typically include chloride, but may also include materials mobilized from basin sediments or aquifer materials as a result of changes in sediment redox conditions or decreasing dissolved oxygen concentrations in groundwater.  Well-maintained facilities are likely to show less impact on groundwater quality, apparently due to removal of fine sediment and maintenance of infiltration capacity, although good maintenance has little effect on highly soluble contaminants. Although contaminant discharges to infiltration systems may be seasonal, determining the arrival time of groundwater including these contaminants at surface waters is complex and beyond the scope of most development proposals. Geologic units with sufficient thickness, areal extent, and high permeability are relatively uncommon, and may support a range of natural and constructed uses not necessarily consistent with infiltration.  These areas are well-defined and mapped in most areas, and GIS tools developed by Maine DEP allow evaluation of the relative risks of various land-use activities and priorities in these areas.

Elevated chloride levels in an urban stream: correlations with impervious cover and winter precipitation events

Karen A. Wilson

Department of Environmental Science, University of Southern Maine, kwilson@usm.maine.edu

Water quality degradation of streams in New England has been a rising concern since the early twentieth century, in large part due to rapid urbanization of land surrounding streams. Impervious cover (IC) plays a major role in this degradation, causing increased runoff to receiving streams, higher peak discharges, greater water export, and higher sediment loads. Long Creek, South Portland, Maine, is an example of an urban impaired stream for which a watershed management plan has been developed to assist in restoration efforts, in part through the use of BMPs and LIDs to reduce IC. In this study, students in the Department of Environmental Science, University of Southern Maine, examined the effect of IC on basic water quality parameters for each sub-watershed of Long Creek and a nearby reference stream during the rarely-studied winter months. Weekly measurements of specific conductance, chloride, and turbidity were made for multiple sites within each sub-watershed from Jan 22, 2013 to April 9, 2013, for a total of 21 sites. As expected, specific conductance and chloride were highly correlated, and both were strongly related to cumulative impervious cover. Spikes in these measures occurred immediately following (or during) precipitation events. Chloride values were above USEPA Aquatic Life Criteria for surface water quality for much of the study period.  It is recommended that further action be taken to regulate the use of salt for deicing purposes on a statewide basis to protect and restore all urban streams.


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