FIRST PLACE – CONCRETE SUPPLY CO., LLC SALISBURY PLANT, SALISBURY, N.C.
As the city of Salisbury has grown up around the site over the past three decades, plant staff has maintained the landscape and contributed to the community. Batch operators keep a daily general housekeeping regimen that includes cleaning of paved areas, clearing washout pit structure, and placing washout debris plus leftover concrete in a drying area to be hauled to aggregate suppliers.
A pit system is designed to catch all of the process water from the batch plant and truck washing operations. Any stormwater in other areas of the yard flow to a detention pond, justifying a prominent banner at the main entrance reading: “We are Earth Friendly, We Recycle Water!”
Concrete Supply has developed an Environmental Management System, boosting the level of oversight within the company. The EMS has positioned the Salisbury plant to attain National Ready Mixed Concrete Association Green-Star certification. The system sees the Corporate Environmental Manager conduct a structured environmental training session annually for each plant, main topics including air emissions, process water handling and continuous improvement per Green-Star goals. Proper wash down procedures and location are stressed to apprise of the potential for damage to the environment, and the impact of violations and fines. The manager also performs indepth, semiannual audits to review air, stormwater and SPCC permit compliance, along with best management and overall environmental practices. Audit results are discussed with the site manager as well as a corrective actions list with a time line for follow-up inspection.
To determine the environmental projects to be funded, the plant looks at the level of impact on the environment as well as the return on investment, i.e. cleaner environment, regulatory compliance, community goodwill.
In addition to Green-Star, the Salisbury plant has undergone an Energy Star audit as part of a company-wide initiative. It provides a baseline of utility usage from which managers and stable are able to develop usage/cost saving strategies. Concrete Supply has installed photocell light switches at Salisbury and other plants to improve the control of when the lights turn on and off., as well as motion sensitive light switches in the restrooms. Energy Star, Green-Star and the EMS have educated, guided, and allowed Concrete Supply to incorporate sustainable practices throughout its operations.
SECOND PLACE – READY MIX USA, LLC GREENEVILLE CONCRETE PLANT, GREENEVILLE, TENN.
While the plant has seen additions and modifications for capacity, air quality and efficiency improvements since opening 42 years ago, owners have kept green space wherever feasible. The operation is built on a sloped site; to the left of the entry are wash rack, parked tankers and the washout area; straight ahead the dispatch office, resale material storage and aggregate piles.
The batch plant and process/storm water collection and drainage point lie below. Process water is filtered through natural grasses and mostly stays onsite in a pond; occasional offsite discharges are sampled according to permit requirements. Storm water that flows on site is caught in a few catch basins that help to filter out solids and slow down flow.
Returned concrete is used to make block or pave the site, and very rarely discarded in a designated discharge area. Plant staff makes traditional and specialty blocks, which bring a significant amount of revenue. Returned-concrete pit material is left to dry and sold as fill.
Like counterparts around Ready Mix USA, the Greeneville plant manager has a structured work obligation: Monthly site inspections; documentation of routine maintenance, training and housekeeping; and, maintaining all items that impact storm water. Upper management is also committed to environmental excellence by supporting plant managers’ efforts to complete needed projects and upgrades.
Commitment is underscored in an attitude that respects environmental laws and implements what is required without hesitation. Ready Mix USA runs training programs for plant managers and key personnel, covering environmental compliance, permits, plans and reporting requirements. All employees are engaged in the 5S program, aiming to create sites where constant progress is being achieved through keeping plant sites clean, orderly and working efficiently.
THIRD PLACE – CEMEX USA ORANGE PARK PLANT, JACKSONVILLE, FLA.
Plant site is just over three acres, 85 percent paved, secured with a 6-ft. chain link fence, and surrounded by mainly light industrial businesses. Best management practices at Orange Park, aimed at state and federal environmental law compliance, include:
- Yard paving, coupled with curb and swale installations, to control and channel stormwater into the sediment traps prior to entering a single pond;
- Floating screen to confine any sediment entering the pond to the south end, allowing for very clean water on the other end;
- Aggregate ground bins area paved and appropriately located along the back of the property to direct runoff to designated areas and eventually to the pond;
- Aggregates are watered for 4- to 7-percent moisture content, minimizing fugitive dust in transfer;
- Tanker drivers are instructed to pump off at 14 psi or less. Automatic overfill valves are on each fill pipe to prevent silo overfilling—they automatically close within five minutes of high-level alarm activation; and,
- Truck idle policy requiring all mixers that do not have a ticket to be loaded must be shut off.
Internal policies and procedures enable Cemex to achieve solid waste recycling and water conservation goals; promote energy-conservation practices; and, reduce plant, vehicle and equipment emissions. A global Health Safety and Environmental Policy posted at Orange Park compels: zero discharge of concrete waste and process water; reduction of fresh water usage by consuming recycled process water for batch mixes, truck washing and drum washout; secondary containment and/or drip containment on all liquid chemical products used or stored; regular plant yard, baghouse and dust collector inspections; and, plant equipment preventive maintenance program.