Thesis: Sc. D., Massachusetts Institute of Technology, Department of Civil Engineering, 1975 / Vita. / Bibliography: leaves 266-271. / Sc. D. / Sc. D. Massachusetts Institute of Technology, Department of Civil Engineering

no abstract provided by author / Master of Architecture

The Potomac River Basin is significant for both public and ecological health as it flows directly into the ecologically-sensitive Chesapeake Bay. It is a drinking water source for about 5 million people living in Maryland, Virginia, and Washington D.C. The discovery of intersex fish, an indicator of poor ecological health, in the Chesapeake Bay occurred in the 2000s, and has led to a series of studies in the watershed to determine the sources and magnitude of endocrine disruption. Endocrine disrupting compounds (EDCs) are exogenous chemicals that interfere with the endocrine system and can cause detrimental health effects at low concentrations. This study aims to understand a best management practice referred to as planned indirect potable reuse (IPR) and its impacts on EDCs. The Occoquan Watershed is a planned IPR subwatershed of the Potomac River Basin. Water samples were collected at the water reclamation plant discharge (Upper Occoquan Service Authority), up- and downstream of that location along Bull Run, and at the water treatment plant intake (Frederick P. Griffith WTP) in the Occoquan Watershed to assess planned IPR. Samples were also collected at a water treatment plant (James J. Corbalis WTP) along the Potomac River for comparison as an unplanned IPR location. These two groups of samples were analyzed for EDCs (categorized into two groups: estrogen hormones and other synthetic organic compounds (SOCs)), nutrients, and other water quality parameters. The infrequency of estrogen hormones and SOC patterns indicate planned and unplanned IPR are both viable approaches to provide safe drinking water / Master of Science / Our river systems are important to maintain both for human and environmental health. The Potomac River Basin is the area of land drained by the Potomac River and its tributaries. The Potomac River Basin is significant for both public and ecological health as it flows directly into the ecologically-sensitive Chesapeake Bay. It is a drinking water source for about 5 million people living in Maryland, Virginia, and Washington D.C. The discovery of intersex fish, or when a single fish has both male and female characteristics, occurred in the Chesapeake Bay in the 2000s. Fish health is often an indicator of poor environmental health, and in this case endocrine disruption. This discovery led to a series of studies in the watershed to determine the sources and magnitude of endocrine disruption. Endocrine disrupting compounds (EDCs) are external chemicals that interfere with the endocrine system once they enter the body of a human or another organism, and can cause detrimental health effects even at low concentrations. This study aims to understand a best management practice, or a type of water pollution control, referred to as planned indirect potable reuse (IPR) and its impacts on EDCs. IPR occurs when wastewater from a community is discharged into to a river or a reservoir, and then downstream it is withdrawn from that same source for drinking water purposes. This can be either planned or unplanned. Planned IPR is becoming more common as population, especially in urban areas, increases. The Occoquan Watershed is a planned IPR subwatershed of the Potomac River Basin. Water samples were collected at the water reclamation plant discharge (Upper Occoquan Service Authority), up- and downstream of that location along Bull Run, and at the water treatment plant intake (Frederick P. Griffith WTP) in the Occoquan Watershed to assess planned IPR. Samples were also collected at a water treatment plant (James J. Corbalis WTP) along the Potomac River for comparison as an unplanned IPR location. These two groups of samples were analyzed for EDCs (categorized into two groups: estrogen hormones and other synthetic organic compounds (SOCs)), nutrients, and other water quality parameters. The infrequency of estrogen hormones and SOC patterns indicate planned and unplanned IPR are both viable approaches to provide safe drinking water.

Human beings have relied on outdoor public spaces for thousands of years to recreate, socialize, exercise, and conduct business. As climate change leads to more severe weather including flooding, prolonged heatwaves, and wildfires, our ability to safely spend time outdoors is increasingly under threat. While a lot of attention has focused on bolstering the resilience of physical infrastructure, social infrastructure such as public parks are often left behind. To address this issue, this project uses East Potomac Park in Washington, DC as a case study to explore architectural interventions to physically and socially adapt parks for climate change. The existing park, which sits on a sinking island constructed in the early 20th century, is frequently forced to close due to tidal flooding. Utilizing a managed retreat along the southwestern edge of the park, the northeastern edge can be reconstructed as a resilient park for the next century. A series of interconnected pavilions each contain a unique architectural program coupled with passive and active environmental strategies to create comfortable recreational opportunities throughout the year. Specifically, sawtooth roofs, brise soleil, and vegetation are explored to manage temperatures, light, and airflow. / Master of Architecture / Human beings have relied on outdoor public spaces for thousands of years to recreate, socialize, exercise, and conduct business. As climate change leads to more severe weather including flooding, prolonged heatwaves, and wildfires, our ability to safely spend time outdoors is increasingly under threat. While a lot of attention has focused on bolstering the resilience of physical infrastructure, such as roads and bridges, social infrastructure such as public parks are often left behind. To address this issue, this project uses East Potomac Park in Washington, DC as a case study to explore architectural strategies to physically and socially adapt parks for climate change. The existing park, which sits on a sinking island constructed in the early 20th century, is frequently forced to close due to tidal flooding. Utilizing a managed retreat along the southwestern edge of the park, the northeastern edge can be reconstructed as a resilient park for the next century with a series of interconnected pavilions housing recreational or social space.

The Chesapeake Bay, once one of the worlds most productive estuaries, has been severely impacted by human activity in the water and on the lands around it. Viewed as an ecosystem, the Bay is no longer able to support the variety and abundance of biota that it was historically able to. Several decades of research on the Chesapeake have pointed to human activities as being the principle reason for this decline. Of these detrimental activities, elevated inputs of Nitrogen and Phosphorus to the Bay were singled out as being the greatest cause of water quality deterioration. The state of Virginia is trying to reduce its annual load of Nitrogen, to the Potomac River, to 60% of what the load was estimated to be in 1985. Virginia would like to accomplish this goal at the lowest cost to its citizens. Therefore the state needs to determine the combination of nitrogen control efforts which will achieve the goal at the lowest cost. The state would also like to be able to maintain nitrogen loads at or below this cap level, indefinitely into the future. This study was undertaken with three primary objectives. The first was to project the level of annual nitrogen inputs to the Potomac River, from the state of Virginia, over the next 15 years. The second was to estimate the minimum annual costs necessary to achieve and maintain a 40% reduction in total nitrogen inputs, using the Virginia's estimated 1985 inputs as a baseline. The final objective was to assess the potential cost savings that may result from using one of two alternative development patterns within the rapidly urbanizing Northern Virginia portion of the Potomac Watershed. The first alternative is prohibiting low-density development within the Northern Virginia region, and the second is to restrict all new development to be within 5 miles of an existing urban area. Study results suggest that there has been no significant progress toward meeting the nitrogen reduction goal, due to the increase in population within the watershed, over the past 13 years. To attain the goal in 1998, a minimum of $27 million, above what is currently being spent annually, would be required. Under the current land use trend within Virginia's Potomac Basin, the annual cost for maintaining the goal is estimated to rise to $38 million annually, in 1998 dollars, by the year 2013. This is a 40% increase in cost. If the first alternative development pattern is adhered to over this 15-year period, then the annual cost will be $33 million, for an annual cost saving of approximately $5 million in 2013. The second alternative could achieve similar results if implemented, costing roughly $5 million less in 2013 than the annual cost per year under the current trend. These findings suggest that the use of alternative development patterns can help slow but not prevent the annual cost, of maintaining the cap, from rising. The study indicates that the reason for the continuous rise in annual cost, over this fifteen-year period, is due primarily to an increase in nitrogen loading to the Potomac that will result from the wastewater disposal needs of the growing population within the Basin. Furthermore, the state will eventually exhaust its lower cost options for reducing Nitrogen loadings, and at that point the annual cost for maintaining the Nitrogen Cap will begin to rise exponentially. Under current land use trends this rapid rise in cost is unlikely to occur within the next 15 years, and is more apt to occur sometime within the next 20 to 40 years. Once annual expenditures begin to rise exponentially it is unlikely that the state of Virginia would be able to maintain its 40% reduction goal. / Master of Science

No description available.