More Than A Wall
One of the most interesting facets of our industry is being called on to resolve an emergency situation that turns out to be an extraordinary opportunity to impact the future of an entire community. This was the case when we were called in to make urgently needed repairs to the City of Troy (NY) seawall due to damage from Hurricane Irene, a storm that tore through Upstate New York in August 2011, leaving nearly $300 million in damage in its path.
Initially, our engineers needed to understand and address some seemingly insurmountable obstacles that would impact our work to repair the wall. These significant complications included the wall’s age of nearly 100 years, the proximity of businesses along the river where work would need to occur, the adjacent wastewater interceptor sewer, and a tidal river environment where tidal changes, seasonal rain and snowmelt increase river flows. With careful planning and coordination among all the parties involved, these obstacles were overcome, and CHA would design a system to repair the wall, with most of the work occurring from barges in the river. A lot of ingenuity was involved – from pumping concrete over buildings to fill the wall, to securing the services of specially trained hardhat dive inspectors using high-definition cameras and video streams to monitor underwater repairs.
The seawall rehabilitation took almost nine years, but what has been truly exciting and gratifying to see is the completion of several “spin-off” projects including a riverside park and a new marina to replace the one destroyed by the hurricane. These public amenities, along with sidewalks and enhanced river access, are encouraging riverfront economic development, building community, reinvigorating tourism along the river, and strengthening the neighborhood in the downtown area. Central to all this positive activity is a wall that now protects the City, its businesses, and its neighborhoods from the threat of flooding.
Engineers set out to stabilize a seawall, but the City of Troy ended up with so much more -- a thriving riverfront and a solid foundation to support more than they ever envisioned.
For more information about seawall stabilization and water resources, contact CHA’s Water Resources Senior Principal Engineer Michael Miller, PE, at firstname.lastname@example.org
Kate Furbish Elementary School
Named after a 19th century botanist whose home was Brunswick, Maine, the new Kate Furbish Elementary School seeks to cultivate curiosity about nature, art, and science in its pre-kindergarten through second-grade students. The school for 660 students was designed by CHA architects around a concept of two schools within a school, which share core facilities. The architectural forms and colors deliberately reduce the scale of the building to help it fit within the surrounding residential neighborhood. The wooded site’s deciduous and coniferous trees inspired the interior design concept—forest trails and markers. Each classroom wing’s name relates to the concept, starting with pre-kindergarten as “Acorns and Pinecones.” As those students advance grade levels, they move into either the “Pine Forest” or “Oak Forest” for kindergarten, first and second grades. Connecting those classroom wings are the primary corridors known as the “Meadow’s Edge” and the “River’s Edge.”
The school’s natural aesthetic is complemented by its sustainable design. The building was designed to receive photovoltaic panels with southern-facing sloped roofs to complement air source heat pumps. Daylighting and views were also considered throughout the building. The Kate Furbish Elementary School welcomed its first students in September 2020.
Niagara County Landfill No. 1
Niagara County Landfill No. 1 is an unlined landfill situated within a limestone quarry in Western New York State. After the site was closed and capped, impacts to groundwater were identified. At one-quarter of the cost of another consultant’s solution, CHA’s remediation plan for the landfill included an alternate cap using a ClosureTurf© system, which met compliance objectives while providing long-term cost savings. The benefits of the clean, always green ClosureTurf© system include its aesthetically pleasing look, elimination of soil erosion problems, improved water quality of stormwater runoff, greater slope stability factor of safety, and quick installation. This solution was also a much more sustainable solution because it eliminated the need for a soil barrier protection layer, eliminating over 1,700 truck trips during construction, and significantly decreasing the project’s carbon footprint. In addition to the alternative cap, our team recommended installing additional leachate collection infrastructure and using monitored natural attenuation to address groundwater contamination.
This project was a 2020 ACEC New York Diamond Award winner and a 2020 ACEC National Recognition Award winner.
Brackish Reverse Osmosis Water Treatment Plant No. 2 and Transmission Mains
The City of Clearwater, Florida, sought a solution to conserve water, produce high quality water from brackish and fresh groundwater, and design a state-of-the-art Reverse Osmosis (RO) Water Treatment Plant (WTP). The project involved providing engineering services to design and construct the $40 million RO WTP No. 2 and associated raw water transmission mains to support 6.25 million gallons per day (MGD). This effort required permitting through local Tampa-area regulatory agencies, including the Florida Department of Environmental Protection (FDEP), Pinellas County, the Florida Department of Transportation (FDOT), and the US Army Corps of Engineers (USACE).
The plant’s design incorporated two treatment trains. The brackish groundwater blended with the concentrate from the City’s RO WTP No. 1 is treated via RO to reduce the salt concentration. The 5.25 MGD of permeate is then ozonated to oxidize sulfide. The freshwater is oxidized with chlorine and then filtered to remove the iron, blended with the ozonated permeate. As the fresh water has a relatively high hardness and alkalinity, the blending of the fresh water and permeates results in stable water after minimum post-treatment. As part of the overall project, a network of more than 60,000 feet of new transmission main piping was required to transmit the raw water from the City’s new wells to the RO WTP No. 2.
This project was awarded the American Public Works Association (APWA) Florida Chapter Project of the Year Award in 2015.
Solar and Daylight Harvesting are Powering Airports
It takes a lot of energy to power an airport, so it is no surprise that airports around the US are investing in sustainable technology to reduce their energy usage and ultimately reduce their carbon footprint. One of the most recent examples of this is the new 1.3 megawatt solar parking canopy at the Evansville Regional Airport (EVV) in Evansville, Indiana. The canopy is the largest in the Midwest and the second largest in the US. This solar canopy is expected to supply approximately 50 percent of the power needed to operate the EVV terminal. EVV married the need for more covered parking spaces in close proximity to the terminal with their desire to become more sustainable by incorporating renewables into their energy mix. In addition to the energy it supplies, the canopy covers those parking spaces closest to the terminal sought by travelers.
The Albany International Airport (ALB) in Albany, New York, also utilizes solar power to reduce its carbon footprint. Rooftop solar panels have been installed on the pedestrian bridge connecting the recently built parking garage to the terminal building. In addition, the garage has been designed with the latest energy-efficient LED fixtures and utilizes motion-sensing/daylight harvesting technology to dim fixtures when ambient lighting is sufficient automatically. Daylight harvesting is a tool to reduce energy usage by dimming or turning off lights based on available natural daylight to light a space. The use of daylight harvesting continually senses the available daylight and maintains a proper amount of light throughout the garage’s five floors.
For more information on the use of solar and daylight harvesting technology at airports, contact CHA’s Aviation Business Line Director Mike DeVoy, PE, at email@example.com