About Agate Construction

Founded in 1981, Agate Construction is based in Clermont, New Jersey, approximately 20 miles south of Atlantic City and 50 miles southeast of Philadelphia. James E. Johnston, Jr., Chairman and CEO, is a Civil Engineering graduate of Manhattan College and licensed Professional Engineer.

In 1992 Johnston’s son James, III, a graduate of Pennsylvania State University, joined the company. Since that time, he has served in various capacities including project manager, estimator and director of operations. In June 2004, Johnston was named president of Agate.

After starting with the Nuclear Division of the Chicago Bridge and Iron Co. and then with Scientific Design, an international petrochemical Design/Build firm, Johnston gravitated to southern New Jersey and worked for two area contractors, becoming well versed in the nuances of the state’s heavy highway and marine construction industry before starting Agate Construction.

Agate focuses on challenging projects that involve groundwater control, structures in the tidal zone, and marine elements. Agate has completed projects throughout New Jersey, Southeastern Pennsylvania, Delaware, and Lower Manhattan. Recent significant projects include over $40 million of outfall and rock groin construction in Deal, NJ; a $20 million marine based, 6-span bridge for Monmouth County in Red Bank, NJ and a $36-million storm drain and pump station project for the NJDOT in Bayhead and Mantoloking, NJ.

1981 – 1992

Agate Construction’s first large-scale work in southern New Jersey involved an addition to an existing wastewater treatment plant and expansion of a county recycling center. Bridgework, additional treatment plant projects, stone sea walls and jetties in Cape May, North Wildwood, and Monmouth Beach, NJ followed these efforts. One of Agate’s most notable successes in the 1980’s was the reconstruction of three timber bridges on Great Bay Boulevard in Tuckerton. At the time, it included the longest pre-fabricated timber bridges on the East Coast.


NJDOT, Rt. 49 Fender Repairs, Salem, NJ 1986

1992 – 2004

agate 322 construction

Rt.322-50 Bridge, Atlantic County, NJ 2001

In pursuit of new challenges in the 1990’s, Agate Construction ventured to areas north and west of southern New Jersey. Working in Manhattan, Agate constructed a new 600-foot pier on the East River, just off Wall Street, as well as a 700-foot promenade in front of the new minor league baseball stadium in Staten Island. At the same time, Agate also completed work in Pennsylvania. Philadelphia is home to the firm’s largest completed work-to-date. Awarded a $22-million contract, Agate successfully installed 8,400 steel piles, at depths of 120 feet, at the Kvaerner Philadelphia Shipyard. Another notable project was the completion of the Route 322 & Interstate 50 in Mays Landing, which was an $8.4-million NJDOT modified Design/Build project.

2005 – Today

Over the last years, Agate’s diversified type of work completed has remained but the scope has grown larger. From 2005 to 2006, Agate completed a 1500-foot seawall with 80,000 tons of rock along the Hereford Inlet in North Wildwood, NJ. Agate then completed its largest project to date, a $53-million bridge over the Mullica River on the Garden State Parkway. This project spanned from 2008 to 2011. In 2016, Agate started its largest subcontract project to date. We earned a subcontract with Manson Construction and constructed outfalls and repaired stone groins on a U.S. Army Corps of Engineer beachfill project in Deal, NJ. The signature feature of the project was a 1,000-foot outfall made up of twin 96-inch reinforced concrete pipes. The project demonstrated Agate’s expertise in water control as we constructed the outfalls in a dynamic beach environment with the Atlantic Ocean pounding on our worksite.

mulica river bridge

Mullica River Bridge, Garden State Pkwy, NJ 2011

Our Affiliate Companies

Currently Bidding Send us a Quote