St. Clare’s Health System – Denville / DA Tank Project

In April 2016, Lockatong Engineering was engaged by St. Clare’s Health System – Denville to perform a Feasibility Study to determine replacement of a deaerator/surge tank, and subsequently handle the bidding process for this replacement and construction monitoring of the project.  The boilers serve the heating needs of the hospital HVAC and sterilization.  The Lockatong team responsible for this project included Robert N. Roop, P.E., President, and Tricia L. Romano, P.E., Sr. Project Engineer.

A site inspection was made in July 2016.  Measurements were taken and tie-in points identified, to determine the feasibility of one of two site locations for the placement of the new DA tank.  One choice was to remove the existing DA and replace it with the new one in the same location.  The second choice was to continue using the old DA and locate the new one in a roofed-over area next to the boiler room.  The need for a rental DA during construction was eliminated by choosing the second choice.  Our findings were submitted to St. Clare’s and the location chosen for the new deaerator and surge tank allowed use of the existing system until the scheduled switch over.

As the project was being authorized, the old DA failed and a rental DA was required, and the project put on the fast track for completion.  The deaerator/surge tank collects building condensate and provides boiler feed water to three existing steam 300 HP boilers and one existing 350 HP boiler.

A bid specification package was prepared and issued to five contractors in September 2016.  The package included specific project scope of work, as well as sequence of construction, constraints, utilities, site upgrades and building modifications.

While Lockatong was preparing the bid specs, we also filed the necessary paperwork with the State of New Jersey Department of Community Affairs, requesting a waiver allowing local construction departments to perform the review of the project.  Our request was approved in August.

During this time, St. Clare’s also engaged Lockatong for the construction monitoring of the project.  This consisted of onsite inspections, commissioning of the installation of the DA/surge tank equipment, associated feed water, transfer pumps and controls; drain and fill of abandoned well water tanks, architectural enclosure of courtyard, mechanical ventilation of enclosed courtyard and demolition of abandoned pipe and old DA.

The project was awarded to PK Mechanical in early 2017. A project kick-off meeting was held with PK Mechanical and hospital staff.  Construction began in February 2017.  It was estimated that construction would last 8 weeks and take place within an area between the two existing boiler rooms. Combustion air requirements for the boiler plant were maintained. Periodic site inspections were made during construction to confirm compliance with design and specification.

Challenges encountered during the project included abandonment of two out-of-service water storage tanks under the location of the new DA.  They were filled with grout to eliminate their eventual collapse.  The second concern was maintaining the exit condition of a stair tower that terminated at grade within the roofed area where the new DA would be located. A new stair landing was constructed with egress path directly to the exterior from the stairway.

Training was provided to boiler plant engineers by Miller and Chitty, manufacturer representatives for Cleaver Brooks, the DA manufacturer.  Training was hands on with each plant engineer engaged in manually switching pump selection, exploring the PLC screen, changing set points or alarms, etc.

On June 29, 2017, boilers were switched over to the new DA tank.  All boilers are now operating on the new DA tank with no problems.  A final inspection was made on August 31, 2017.  A final deliverable to the hospital was a comprehensive recommended spares list to be purchased and maintained on site.