Grayslake Gate Station Modernization Project

Firm: Hampton, Lenzini and Renwick, Inc.

Other Consultants: Valdes Engineering, Farnsworth Group, KPRG and Associates, Inc., Meade

Owner:North Shore Gas

Description:For 115 years, North Shore Gas has delivered safe, reliable natural gas to residents and businesses in 50+ communities throughout the Lake County, Illinois region. Before natural gas in a transmission pipe reaches a local gas utility, it typically passes through a gate station. Gate stations remove contaminants from the gas, measure flow rate and gas quality, heat the gas to prevent condensation of hydrates when the gas pressure is reduced, and add an odorant to provide a distinct odor for leak detection.

The existing gate station, which controls most of the natural gas distributed throughout Lake County, was constructed in 1941 and required upgrades to comply with specifications and correct deficiencies within the existing system.

Unlike other territories, the Grayslake Gate Station does not have a redundant supply to support the area, which required North Shore Gas to rethink and re-engineer how the gate station was designed to ensure reliability throughout the year. Redundant heaters were installed with control valves placed at each heater for ease of maintenance, efficiency, and reliability. This unique application minimizes the amount of energy used, as only one heater is needed during the summer months, and only the amount of gas that requires heating is supplied to the heaters. Odorant waste gas is utilized in the line heaters instead of using a flare to burn it off, which leads to odorant complaints, and redundant regulator train with noise-limiting trim reduces noise pollution for the surrounding community and businesses. An updated metering system accurately tracks usage for future planning.

The modernization project also presented significant location, environmental, and drainage challenges due to flooding from off-site areas that drained through the northern section of the gate station. The site footprint could not be expanded due to wetlands to north, Peterson Road to the south, a railroad to the east, and farmland to the west which was unavailable for purchase. However, the Libertyville Zoning Board of Appeals approved a variation to reduce the minimum required Perimeter Landscaped Open Space, which requires a combination of shade, ornamental trees, evergreens, and shrubs along the perimeter property line.

Runoff is now collected and drained through a bypass storm sewer to convey the flow around the site. A drainage system was also constructed within the site to collect and drain runoff into a new underground stormwater detention system. Stormwater is detained in the voids of aggregate beneath a new pervious GeoBlock grass area to reduce impervious area and volume of runoff. Landscaping for the site was carefully selected to meet Libertyville ordinance requirements, support the natural habitat of local wildlife, and enhance the appearance of the gate station.

All challenges that this project presented were overcome by redefining current engineering thinking, unique applications, exceptional teamwork, and intricate communication between all parties and the community.

The Grayslake Gate Station Modernization Project enhanced the reliability, safety, and security of the natural gas system for North Shore Gas customers in Lake County.

North Shore Gas

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