Opportunity
In 1886, a group of professors at Swarthmore College were granted a charter to supply water to residents of Springfield Township in Pennsylvania’s Delaware County.
Their association was later incorporated as the Springfield Water Company, which eventually grew into Aqua America. Today the company provides drinking water and wastewater services to about 3 million people in 10 states.
With the passing of time, many of Aqua America’s aging facilities require evaluation, upgrading, and sometimes replacement. Aqua America’s continuing growth through acquisition has also created the need to assess, value, and upgrade facilities originally built and maintained by other companies.
Solution
Mott MacDonald has used its expertise to improve water and wastewater systems at Aqua America facilities in New Jersey and Pennsylvania. Our services have included water system valuation, water quality investigation, pilot testing, field surveys, feasibility studies, hydraulic analysis, preliminary and final design, plans and specifications, bid assistance, construction management, and permit services.
New Jersey
Berkeley Township: water valuation
In 2005, Aqua New Jersey purchased the assets of the Berkeley Water Company in Ocean County, including three wells, two storage tanks, and about 50 miles (80 kilometers) of distribution mains. Aqua New Jersey retained us to prepare an inventory and assign a present value to the assets of the distribution system. This was required so the company could report it to the Board of Public Utilities and justify its proposed water rates.
Mott MacDonald developed a GIS distribution map, identified mains based on size, material, and year constructed, developed a replacement cost for each type of main, and set the current value of each asset using standard depreciation rates.
Gloucester Township: IPMP contamination
Well No. 14 in Aqua New Jersey’s Blackwood Well Field was placed in service in 1994 and removed from service only two years later, after consumers complained of a musty odor in the water. The source of the odor was identified as isopropyl-methoxy-pyrazine, a harmless contaminant that rendered well water unusable unless blended with water from another source.
We were retained to determine the extent of IPMP contamination, and possible remedies. After research and interviews with utilities and state agencies, we determined that the contamination was regional, probably caused by nearby surface water or wetlands. We recommended the use of a lignite coal-based activated carbon system to treat Well No. 14.
Hamilton Township: pressure filter improvement
Aqua New Jersey’s well station and pressure filtration plant in Hamilton Township discharged its backwash wastewater to sand drying beds and then a stream. When discharges were found to exceed state water quality limitations, Mott MacDonald was retained to investigate alternatives.
In order to regulate the time and rate of discharge, we recommended and prepared plans and specifications for a 100,000-gallon (378,000-liter) holding tank set on a conical concrete foundation and connected to the sanitary sewer, including a submersible pump, flow control devices, and an instrumentation and control system.
Due to problems obtaining Planning Board approval, we then conducted a study concluding that two dewatering lagoons, each 23 by 68 feet (7 by 21 meters) wide and 10 feet (3 meters) deep, could discharge decanted water to the sand drying beds, with ultimate discharge to the stream.
Phillipsburg: UV treatment and well monitoring facility
For Aqua America’s wells in Phillipsburg, which draw from high-quality groundwater with low turbidity, we prepared the documentation needed for the company to obtain its first Filter Avoidance Waiver from the New Jersey Department of Environmental Protection.
The waiver required that a disinfection system be installed. Our analysis indicated that the use of a low-pressure high-output UV disinfection system was the most cost-effective option, saving more than $10 million over the cost of a membrane system with a similar capacity.
Pennsylvania
Crum Creek Residuals Treatment Facility
For Aqua Pennsylvania, we met an aggressive schedule for designing a new residuals treatment facility to replace an existing system that was limited and inefficient. We used a design-build delivery method and building information modeling (BIM) to design and prepare plans and specifications for a facility that would dewater residuals mechanically, using belt filter press technology.
We also supplied complete construction phase administration and inspection services for the facility, assisted with startup and testing, and prepared an operations and maintenance manual and record plans for the completed work.
Edgely Water Treatment Plant upgrade
Aqua Pennsylvania’s Edgely plant required an upgrade to meet its required capacity of 6 million gallons per day (MGD) and stringent water quality regulations.
Mott MacDonald was retained to provide design, bidding, permitting, and construction phase services for upgrades to two aeration towers, a high-density lime system, an on-site sodium hypochlorite generation system, and pumps, as well as replacement of the electrical, instrumentation, and control systems.
We used BIM technology to create an interactive 3D model of the facility, and design was completed a full month ahead of schedule.
Neshaminy Water Treatment Plant upgrade
To ensure that its Neshaminy plant could meet future water quality standards, Aqua Pennsylvania retained us in 2007 to provide a detailed evaluation of the water treatment system and a plan for improvements, and later to provide design and construction phase services.
We also reviewed the quality of the source water with emphasis on taste and odor concerns in order to develop an alternative clarification process. We prepared two construction contracts for the cleaning and lining of the raw water transmission mains, major upgrades to the pretreatment and residuals systems, and a new UV/hydrogen peroxide system for advanced taste and odor treatment.
Shenango Water Treatment Plant: treatability study
Aqua Pennsylvania’s 16-MGD Shenango facility draws water from the Shenango River, which has period of high turbidity, algae, and taste and odor problems. In 2011, we were retained to perform a treatability study that led to a multifaceted testing program.
Our study recommended dissolved air flotation, replacement of the filter media, and conversion of the primary disinfection system from free chlorine to chlorine dioxide. Demonstration testing of the chlorine dioxide system documented a 40% reduction of haloacetic acids (HAA) and a 50% reduction in total trihalomethanes (TTHM).
Outcome
Through a variety of services, Mott MacDonald has helped Aqua America maintain water quality, upgrade its facilities cost-effectively, and continue its program of acquisitions.
We have diagnosed taste and odor problems, achieved large measurable reductions in contaminants, provided justification for water rates, helped Aqua America meet stringent regulatory requirements, and identified significant cost savings — enabling the Phillipsburg facility alone to avoid the cost of filtration and save $10 million by using UV rather than a membrane system for treatment.
Our use of BIM technology has also given Aqua America a tool that will continue to provide benefits into the future, enabling the company to identify problems and opportunities more effectively than before.