Using Historical Development Data to Understand Current Urban Flooding and Pollutant Transport
In heavily-urban areas such as Middletown, PA, development pre-dated the installation of water distribution and waste collection systems. The borough developed around several historical streams and springs and was affected by its location at the confluence of the Susquehanna River and Swatara Creek. This research project focuses on how the development and relocation of water resources has impacted theflash flooding in the area and will eventually focus on water-quality issues.
The Campus as a Living Lab to Highlight Water Resources Preservation and Sustainability
The land upon which Penn State Harrisburg sits was once the home of the Susquehannocks and prior indigenous tribes whose names we do not know. These indigenous tribes used the rivers and creeks as a water and food source, and also practiced agriculture in the floodplains. In the mid-to-late 1700s, Europeans moved to the region, receiving land warrants from William Penn and his descendants. Since that time, the land has modified by additional land clearing using hand tools and animal-powered agricultural implements that created terraces and other improvements to increase crop yields. The campus also was home to military encampments dating back to the Revolutionary War through the Spanish-American War, and finally to the Olmsted Air Force Base prior to being turned over to Penn State University to create the campus now known as Penn State Harrisburg. Understanding the impacts of the long history of land modification on stormwater movement, water resources preservation, and sustainability drives this series of student-centered projects.
- Project 1: Modeling of the Storm Sewer System Draining the Campus Watershed. Two senior capstone projects, plus two graduate students, developed and field-verified a PCSWMM model of the drainage system that contains the Penn State Harrisburg campus.
- Project 2: Characterization of an Urban Stream on the PSH Campus undergoing Degradation and Evolution. As the campus plans for growth, the impact of this development on the ephemeral stream running through the middle of campus needed to be evaluated and eventually minimized. This was a baseline study to understand the stream health in the mid-2000s, prior to the expansion of the EAB building and the addition of the Student Enrichment Center. Additional activities include modeling of the stream and potential erosion in HEC-RAS both as a class activity and as a master’s project.
- Project 3: Behavior of the Stormwater Pond behind the Boiler Plant Building. This pond receives drainage from the warehousing facility above campus and from the newest parking lot on the west side of campus. The pond has been renovated at least once since it was built several decades earlier. The pond is designed to have water temporarily retained for several days to weeks after a storm (the outlet is approximately 1 ft above the bottom of the pond) with slow infiltration removing the remaining water. Inflow from the warehousing facility was monitored in 2020 using level-temperature-conductivity meters. In winter 2020, the conductivity from the inlet to the outlet was measured along the transect of the retained water. In late 2020, a Zentra Teros 12 soil sensor system was installed so that infiltration also can be quantified, plus additional flow meters were installed at the inlet from the campus west parking lot and in the sediment forebay of the pond.
- Project 4: Impact of Soil Structure Changes and Compaction Depth on Stormwater Runoff Quantity.
Treatment of Stormwater by Filtration
This series of projects have focused on the use of sorbents, particularly natural ones, to remove a variety of particulate and dissolved pollutants from stormwater.
- Project 1: Media Filtration for Residential/Commercial Stormwater Treatment. Low-maintenance, passive stormwater treatment technologies are required for retrofitting in urban critical source areas. Various media were evaluated for their potential to remove and retain a suite of pollutants from low concentration residential and/or commercial runoff. These results are application both to media filter systems and to bioretention systems.
- Project 2: Characterizing Natural Soils’ Ability to Remove Stormwater Pollutants during Infiltration. Studies have reported the removal of many pollutants from stormwater runoff by natural soils. Few have characterized the impact that the various soil layers have on that removal ability. This laboratory study examined two soils (silty loam and loamy sand) for their ability to remove pollutants (nutrients and metals) from stormwater runoff by analyzing removal in the entire soil column, versus removal in the O, A, and B soil segments.
- Project 3: Optimizing Bioretention Media for Stormwater Treatment of Conventional and Unconventional Pollutants. To meet the discharge permit requirements for the Santa Susana site in southern California, several sands, zeolites, an activated carbon, compost, and peat moss were evaluated for their ability to remove nutrients, metals, radionuclides, and organics such as perchlorates and dioxins. The report can be found here.
- Project 4: Upflow Filtration for Urban Stormwater Treatment. Runoff treatment for urban critical source areas requires technology that is low maintenance and that requires limited land area. Upflow filters with four media choices were investigated for their treatment potential.
Road Salts and their Impact on Roadside Soils and Stormwater Management Systems
Road salt is used on paved surfaces to remove snow and particularly ice in order to keep pedestrians and vehicles safe. When rainfall contacts pavements with a residual salt cover or passes through piles of snow and ice that have been scraped off paved surfaces, the salts are transported in the runoff to the soil or stormwater system.
- Project 1: Laboratory Examination of Salt Impacts on Flow and Metals Migration. Salts interact with the soil, potentially sealing them to future flows. They also participate in ion-exchange/adsorption reactions, dislodging previously-trapped ions and transporting them deeper into the soil profile. (Project Co-Lead: Dr. Sai Kakuturu)
- Project 2: Field Examination of City of Lancaster Bioretention System Subject to Road Salt Loadings (Current). Because road salts are not applied year-round, their impacts are cyclic. This 2-year project is using flow data (flow, temperature, conductivity) combined with soil data (moisture content, temperature, electrical conductivity) to evaluate the transport of road salts through the system, looking for potential salt buildup during the winter and flushing during the summer.
Stream Restoration: Short- and Long-Term Effectiveness of Restoration Techniques
Two common methods of stream restoration are engineered bank stabilization and reconnection of the floodplain to the stream. Both methods are designed to reduce the erosion of the streambank, thus reducing the movement of the bank soils and the associated nutrients with them.
- Project 1: Codorus Creek, York County, PA.
- Project 2: Floodplain Reconnection versus Streambank Stabilization, Lancaster County, PA. This project is investigating nutrient cycling, sediment transport, and biologic diversity upstream, in the middle of the restoration, at the end of the restoration, and downstream of several agricultural restoration projects to better understand the effectiveness of each type of restoration. (Project Co-Lead: Dr. Jennifer Sliko)
- Project 3: Long-Term Effectiveness of Multiple Restoration Projects on Santo Domingo Creek and Lititz Run, Lititz, PA. Stream restoration has been monitored primarily during the first 1 – 3 years post-restoration. On Lititz Run, many restoration projects were completed in the late 1990s and early 2000s. Citizen monitoring has occurred multiple times a year at a few locations along the creeks, but no one has studied the water quality as the water moves through the restorations downstream. This project takes a detailed view of the effectiveness of restoration 10 – 25 years post-restoration. (Project Co-Lead: Dr. Jennifer Sliko)
Improving Stormwater Treatment Designs to Achieve Water Quality Goals
Advances in stormwater science have not been fully incorporated into treatment system designs. This project aims to improve incorporation of water and wastewater treatment theory into design equations. Calibration and validation data will come from the International BMP Database (http://bmpdatabase.org). Statistical analyses such as simple correlations and cluster analyses will be used to determine correlations between design parameters that engineers can control to effluent water quality from stormwater treatment systems.
Recycled Computer Glass in Concrete: Impact of Environmental Exposures on Pollutant Release
As plasma and LED screens start failing, many will be sent to recycling facilities. If alternative uses for the glass are not found, the glass will be landfilled. CRT glass has been used successfully as a building material by incorporating it into concrete as part of the aggregate. This project is focused on incorporating plasma TV glass into concrete, and then testing its structural properties and environmental leaching potential both through traditional TCLP testing and through periodic exposure to simulated rainwater at various stages of accelerated aging. (Project Lead: Dr. Grady Mathews)
Non-Technical Barriers to Green Stormwater Infrastructure Implementation
The technology and knowledge supporting green stormwater infrastructure and low impact development has advanced over the last 20 years. Hoewever, in many places, green infrastructure has not been widely adopted. Surveys of the design, regulatory, and regulated communities are being used to better understand the non-technical barriers to green infrastructure implementation.
Green Roof Media Evaluation: Pollutant Retention, Runoff Water Quality, and Heat Transfer Properties
Green (vegetated) roofs are one of the options in the stormwater management toolbox. The first project investigating green roofs was determining the water quality of the runoff after passing through a commercial media that had been vegetated with sedum plugs. The particular interest was in the effluent water quality during plant establishment. Second, the group investigated the potential of replacing part or all of the organic and inorganic components of the media with recycled materials in terms of water quality and plant growth. Currently, the research group is investigating the heat transfer and heat retention ability of several green roof media components under a variety of temperature conditions and moisture contents. The goal is to improve the modeling of heat transfer through these potential green roof media. (Project Co-Lead: Dr. Rashid Kaveh)
Improving Treatment of Industrial Stormwater Runoff
Two projects, including an ongoing one, have investigated the potential for optimizing filtration/biofiltration media for stormwater runoff associated with an industrial site. In 2009 – 2010, this research group performed a series of laboratory tests on candidate media, both individually and in various combinations, for their ability to remove sediment, nutrients, metals, organics, radionuclides, and dioxin from stormwater runoff (Project Co-PI: Dr. Robert Pitt, University of Alabama). Other activities have included evaluating the ability of a variety of sedimentation and filtration devices currently deployed in the field at industrial sites for their abilty to treat site runoff to where it meets the MSGP benchmarks. Currently, we are investigating the potential of surface modification of diatomaceous earth to remove metals from industrial stormwater runoff. (Project Co-Lead: Dr. Farrah Moazeni)
Roofing Materials as a Contributor to Urban Runoff Pollution
This was a multi-year investigation into the pollutant contributions of common roofing materials (roofing felt, asphalt shingles, treated and untreated wood, vinyl roofing panels, galvanized metal, cedar shakes, etc.).
Rainfall Energy for Erosion (R): Comparison of Map Values versus Calculated
The RUSLE equation defines a parameter R as the measure of the erosive energy of the rainfall. US EPA proposed an alternate equation to caluclate R for Type II rains. This project compared the map vlaues with the calculated R values for several rain depths for many stations in PA. Calculated R values were always much greater (50 – 100%).
Collection and Measurement of Stormwater Solids
Sedimentation is a leading cause of receiving water degradation and stormwater from urban surfaces is a substantial contributor. Because of its importantce in water quality evaluations, understanding the limitations of the various methods of collecting and analyzing samples with solids is vital.
Decision Guidance: Infiltration vs Surface Water Discharge
WERF Funded Project: Development of guidance to aid stormwater managers in selecting between surface water discharge and infiltration when determining which stormwater option to select for a site. Review of modeling capabilities to predict potential for groundwater contamination below infiltration devices.
Environmental Technology Verification (US EPA protocols) for Stormwater Treatment Technologies
Terre Kleen(TM) (Terre Hill Concrete Products: Full scale field testing of an inclined plate settler.
Up-Flo(R) Filter (Hydro International): Full-scale laboratory testing of an upflow filter.