New York City dwellers get their drinking water from a 19 reservoir water system located within a massive watershed extending over 2,000 square miles. This watershed geographically falls within three distinct regions which are; the Catskill/Delaware, the Hudson River and the Croton which comprises of three controlled lakes and 12 reservoirs. The Croton System happens to be the oldest and the smallest of the three water systems; it was initially only a water reservoir system supplying water from outside the City. Presently it provides approximately 10 percent of the City’s daily water filtration demands. This system generally serves with a gravity conveyed system to low-lying areas within the Bronx and Manhattan.
However, the Croton water System was perennially exposed to the threat of contamination. This was mainly due to storm water run-off which results in pollution incidents and entire shut downs historically. Following the 1989 Safe Drinking Water Act which ordered the filtration of all surface drinking water by June 1993, the New York City Department of Environmental Protection started preparations for this massive process. A project was then proposed to meet these new State and federal drinking water regulations and standards as well as provide a safe and healthy water supply to the dwellers of New York City.
The Croton Water Filtration Plant’s Site preparation started in September 2004. The construction of the facility then commenced in August 2007 and envisions an entire plant floor of about 830 feet long by 555 feet wide by 90 feet deep in the rock. This is the single largest construction project going on right now in New York which culminates in 2012 bringing to an end a very long and controversial saga. Concisely, the project involves serious construction challenges of drilling, blasting and excavating of about 1,106,000 cubic yards of rock and soil. Construction work at the site necessitates work on concrete area placements, installation of mechanical, electrical, heat, ventilation, and plumbing works. The concrete roof area over the plant is approximately 341,000 square feet and the pending work at site is the connection of the existing connection systems to the newly treated water shafts.
This new Water Treatment is the first to be actually built within New York’s boroughs on a 12-acre site beneath the Mosholu Golf Course in the Bronx. Ten acres of the site will be reverted back into the municipal golf course upon completion. The underground plant harbors two water tunnels accessing the filtration system and a four-storey plant.
The filtration system was initially projected to filter 1.1 million cubic meters each day but an additional 100,000m³ a day was fostered into a new contract. This figure is about 10% of New York’s daily water demand that may be increased three times in case of drought or severe need.
The main construction phase involves the putting up of the treatment plant itself, an administration office block and a site laboratory. Additionally this will include a chemical storage and processing facilities for backwash water, necessary ancillary electrical and a SCADA monitoring system. In relation to this, the whole process must deliver a crude water tunnel from the New Croton Aqueduct together with a wet well and pumping station. A matching arrangement for the treated water linking to the distribution network should also be in place.
The overall technical requirements for the system include the installation of Ovation controllers, 4 operator interfaces and 12 workstations. There will also be a provision of ‘smart’ devices’ such as magnetic flow-meters, automatic chlorination analyzers and pressure / temperature sensors and transmitters. The original construction project cost was $1.3 billion, this was revised as of September 2009 to a cost of approximately $2bn. Out of this only $95 million was set apart for above ground structures (Clubhouse, guard house, Tee Box structures, Chemical fill building and Arrivals / Receiving Building ) and landscaping needs. The rest is dedicated towards the construction of the underground treatment plant. The rest of the cost breakdown is briefly indicated as below:
Construction Cost Breakdown:
• Site Preparation: $127,660,000 – completed
• Treatment Plant: $1,537,855,000 – under construction
• Water Tunnels: $209,444,000 – under construction)
• Modifications at Jerome Park Reservoir: $4,448,000 – under construction
• Force Main: $25,000,000 – estimate
• Off-Site: 114,000,000 – estimate
The major sponsor of this project is the New York City Department of Environmental Protection who will eventually run the plant. The main project contractor is a Skanska / Tully Construction joint venture, with Haley & Aldrich as geo-technical consultants. The digital automation architecture is being provided by Emerson and a Hazen & Sawyer / Metcalf & Eddy JV as the client consultant. This Croton Water Filtration Plant is chiefly propelled by Mayor Bloomberg’s PlaNYC aim to better the reliability and the overall sustainability of New York City’s water infrastructure. It is among the projects comprising of the Strategy 2011-2014 which aims at making DEP into a safe, efficient and cost-effective water utility system. The three key design considerations for the above ground structures and landscape of the Croton project were:
• Design of Artistic structures and creative integration of buildings to the landscape
• Creation of recreation and education facilities
• Demonstration of a sustainable design through the best practices of storm water management and site design
The main overall goals of this complex hydrological storm water system are to;
• Significantly treat ground and storm water through constructed wetlands and bio-swales
• Significantly reduce all groundwater and storm water discharge into the city combined sewer through site reuse, including golf course and driving range irrigation, grey water uses, wetland recharge, and building maintenance
The was an initial management resolution to have in place an effective document management tool for the management of the building drawing review process, tracking the progress/submittal status, sharing of information with multiple stakeholders, monitoring of all comment resolution and sharing of contract documents among multiple offices and ensuring that the most current version is used.
The overall control and monitoring techniques involved relies majorly on NYCDEP who have well-defined monitoring and reporting requirements. However, the construction managers handling the Croton Water Filtration Plant painstakingly designed Tight Consent Decree schedules, reviewed Tens of thousands of contractor submittals, had reviewers in six offices throughout east coast, employed the Wicks Law of Multiple Construction Contracts amounting to 19 in total and settled on two major design firms and several sub-contractors. They selected the “Constructware” construction software to do their logistical procedures due to its Security, Expandability and Ease of Access which is internet based.
According to the initial planning records, the plant construction began in 1997, since then it has been marred by difficulties and controversies which have led to a very slow progress. The federal government has even filed a legal suit against New York City. The contract decrees had to be amended several times to accommodate the extension of various deadlines. Moreover, the project is much overdue and over-budget due to reasons such as poor initial design and planning procedures, many design adjustments during construction and lack of focus/ slow execution at the management level.
The bare magnitude and project implementation is of particular significant importance to the overall design and project progression. To ensure a smooth construction management process, the management should have carefully balanced the massive Water treatment endeavor with careful monitoring and controlling of key procedures, deadlines and budget allocations.
For better project management and effective cost efficiency the management should try to:
- Ensure that the cost estimates cohere to the initial estimating guidelines projected in the “cost estimating manuals”;
- See to it that the engineering audit officials file appropriate evidence showing substantial documentations of costs incurred;
- Develop conceptual cost approximations containing sufficient substantiating information;
- Adjust cost estimates to cater for unanticipated issues of inflation, labor dynamics and material / equipment cost fluctuations;
- Review the consultant’s recommendations and documentation often.