Environmentally Speaking - eNewsletter for the A/E/C Community

Dike Rehabilitation Design

Southern Florida

Located in south central Florida, Lake Okeechobee covers about 730 square miles. The lake is surrounded by the Herbert Hoover Dike, an approximately 143-mile-long earth embankment.

Lake Okeechobee experienced high water events in the late '90s, resulting in significant seepage through and beneath the Herbert Hoover Dike. This created sinkholes, boils and internal erosion due to piping.

Gannett Fleming was engaged as an engineering subcontractor to provide analysis and design of rehabilitation measures for this dike rehabilitation assignment. Activities included seepage and stability analysis and design services for a cutoff and toe drain/buttress previously developed by the USACE.

Alternatives were evaluated for the berm length, cutoff depth and drainage trench/ relief well concepts. Project tasks include:

preliminary design of rehabilitation alternatives
alternatives, seepage and slope stability studies
filter and drain compatibility evaluation
quantities and cost estimates
structure earth loading determination
alternative structure cut-off wall analysis and appropriate connection to dike cut-off wall
geological characterization
seismic and liquefaction analysis
instrumentation

Design drawings will be developed for the preferred solution. This project is led by the Jacksonville, FL, Corporate Geotechnical Practice Manager, Jim Langer, PE, with support from Phoenix, AZ, Senior Geotechnical Engineer, Dean Durkee [bio].

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Energy Generation:
Poultry Power

The cost to generate power is constantly increasing due to an inadequate supply of reliable, affordable and renewable fuels. Consequently, poultry manure may be a viable fuel source worth investigating.

This region could also provide an economical co-firing alternative to an existing plant.

One of the largest producers of poultry manure in the Chesapeake Bay Watershed, south central Pennsylvania could offer a steady fuel source for a manure-fired power plant.

Trucking costs associated with manure transport may prove problematic, which is why distributed models must be explored and other energy sources considered (read regs/programs).

Renewable Credit

Renewable Energy Credits (REC) can also be obtained by converting poultry manure into a renewable fuel. These credits represent environmental attributes from electricity generated by renewable energy.

REC prices have not yet been solidified because of the relatively new REC market.

REC can be sold separately from the electricity generated and, in turn, provide additional revenue. Electric companies that do not produce renewable energy are able to buy REC to offset traditional power generation.

Environmental Management Specialist, Bill Achor [bio], has been instrumental in investigating related renewable energy project alternatives.

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Maryland Dam Safety
Emergency Action Planning

Gannett Fleming tasks support Baltimore's continued maintenance efforts, consistent with MDE goals, to ensure dam safety and reliability.

Liberty [pictured above], Loch Raven and Prettyboy Dams store over 65 billion gallons of raw water.

The Maryland Department of the Environment (MDE) has modified the format for Emergency Action Plans (EAPs). MDE is now requiring dam owners throughout Maryland to submit revised EAPs consistent with these new requirements.

Baltimore Project Manager, Dave Smyth, PE, recently assisted the City of Baltimore with updating and revising EAPs for the Liberty Dam, Loch Raven Dam [awards] and Prettyboy Dam. These three dams serve the City as well as portions of Baltimore, Anne Arundel, Howard, Carroll and Harford Counties.

Dave, Baltimore Construction Manager, Dale Sweitzer, and Gordon Warren, PE (Harrisburg, PA), additionally performed physical inspections of each dam. The team will develop and update site-specific O&M plans.

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West Coast Site Remediation

Gannett Fleming, Inc., has started a Site Remediation practice in Southern California. Based in Los Angeles and Orange County, this practice is under the leadership of Leo Rebele [bio]. The group's focus is to expand the Gannett Fleming and TerraSure portfolio of remediation projects, particularly in the Brownfields arena. Additionally, the practice will build upon Gannett Fleming's existing national service lines in the manufacturing, oil & gas, pharmaceutical and transportation industries.

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Alternative Energy Sources
Agri-Business Opportunities

Promoting manure-to-energy plants is one of the 12 major Pennsylvania initiatives to help the state achieve Chesapeake Bay nutrient and sediment reduction goals. Due to increasing nitrogen and phosphorus regulations (major poultry manure components), proper poultry manure disposition is proving more difficult. As a result, poultry manure (read news) may be inexpensive to obtain for various alternative energy scenarios.

Electrons, compressed gases (hydrogen, heat, steam and combined heat) and power are all natural outcomes of organic residual conversion.

Manures, however, should not be the only feedstock considered in renewable energy projects for the systems to remain viable. This alternative must be combined with other organic residuals to achieve true sustainable equilibrium.

Environmental Management Specialist, Bill Achor [bio], is a primary contact in the agri-business sector.

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Hydrologic GIS
Dam Engineering Benefits

Constructing hydrologic models to compute dam inflow hydrographs can be time consuming depending on the detail and size of the watershed. As reported last April, geographic information systems facilitate this process by offering speed, flexibility, graphics and methodology.

Larger watersheds for dam projects were not refined in the past. Typically, dams were modeled with a single watershed upstream.

Thanks to GIS, watershed delineation, parameter estimation and model input file creation are accomplished with a few clicks of the mouse. Furthermore, hydrologic models built within GIS are easy to edit. This flexibility enables a large watershed to be seamlessly divided into numerous sub-watersheds.

Moreover, watersheds can be broken into a cellular grid and runoff parameters and rainfall distributions can be computed at the cell level. Illustrated below is the watershed scale compared to a cellular scale.

Graphically representing a cellular polygon is a useful technique when conducting detailed probable maximum flood studies. In fact, estimating initial abstraction for a watershed or sub-watersheds can be greatly enhanced and provide more detail using this method.

Chris Krebs [bio] leads Gannett Fleming's Environmental Resource GIS efforts.

This is just one example of how hydrologic GIS tools help to solve complex problems while not relying on historical large-scale averages.

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Innovative Sewer Main Construction
Arizona Pipe Bursting

The first major Phoenix pipe bursting project, this effort addressed Arizona's recently passed capacity, management, operation and maintenance (CMOM) program.

The City of Phoenix, AZ, implemented a project to upsize small diameter sewers to convey increasing wastewater flows being discharged to the Phoenix system. Alan O'Brien, PE, recently completed design and construction services for this assignment using pipe bursting with High-Density Polyethylene (HDPE) as the replacement pipe. The bursts were completed in three areas to upsize 10-inch Vitrified Clay Pipe sewer mains to 14-inch and 18-inch HDPE.

Considering traffic and construction concerns, pipe bursting was identified as a safe and cost-effective Phoenix alternative to normal open-trench sewer construction.

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Modeling Application
Coastal and Estuarine Study

Our June edition featured other SJRWMD water infrastructure and resource projects.

GeoDecisions [press release] Geographic Information System personnel in Madison, WI, are participating in a surface water quality and monitoring assessment program for the St. Johns River Water Management District (SJRWMD) in Palatka, FL. The project's focus is to evaluate and test the Analytical Framework for Coastal and Estuarine Study (ACES) modeling application.

ACES is being considered for use by numerous agencies, including the USEPA. Recommendations made by GeoDecisions will help guide future efforts for continued ACES development.

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Composting and Recycling Leadership

Professional Recyclers of Pennsylvania (PROP) President, Lori Robson, [bio], was a keynote speaker during the organization's recent annual conference held in Gettysburg, PA. The event included various sessions on composting and recycling enforcement, outreach, operations and identifying alternative funding sources.

PROP, the largest non-profit recycling organization in Pennsylvania, is also hosting next month's National Recycling Coalition (NRC) Annual Congress and Exposition in Pittsburgh, PA. Both Lori and Steve Deasy [bio] will attend the NRC event, for which Gannett Fleming is a sustainability sponsor.

Lori and Steve previously authored PROP articles discussing Act 101 and leaf waste.

Steve is also spearheading Gannett Fleming initiatives to evaluate energy-saving strategies and policies and expand corporate electronics recycling.

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Dam Safety Distinctions

Watres Dam [pictured above] is a large, high-hazard, water supply earth embankment with a partial concrete cutoff wall.

Scott Brough (Resident Project Representative), Gordon Warren, PE, and Robert Saber, PE, co-authored a paper with Anthony Nokovich, PE, a Senior Engineer with the Pennsylvania-American Water Company (PAWC), highlighting embankment slope stability, seepage and spillway capacity issues at the Watres Dam in Lackawanna County, PA.

The authors discuss design considerations, including operational requirements imposed by the dam owner/operator (PAWC), which influenced selection of design features to remediate the dam while maintaining the reservoir at 95 percent full.

Tony will present this paper at the Association of State Dam Safety Officials (ASDSO) Annual Conference in Indian Wells, CA, next month. New Mexico Senior Geotechnical Engineer, Dwayne Lillard [bio], will also receive an ASDSO "Award of Merit" at the event.

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» Dam Safety 2008 (California)

» Environmental and Water Resources Institute (ASCE)

» Hawaii Department of Land and Natural Resources

» National Recycling Coalition
» Renewable Energy Incentives (Pennsylvania)