Rigid pavement maintenance activities are designed to provide safety, preserve the state's capital investment and maintain a riding quality that is satisfactory to the traveling public. Road surface maintenance typically involves the use of concrete and other materials to create impervious surface areas or to repair existing road surfaces. Pollution control activities focus on ensuring that removed materials and Portland cement concrete wastes remain controlled and are not released to the environment.

Environmental stewardship practices for ready mix concrete operations include, and were initially developed for the Frasier Basin, in British Columbia: [N]

• Reduction of use of toxic substances, raw materials and nonrenewables.
• Reuse of recovered raw material, products and hazardous substances.
• Elimination or minimization of environmental releases.
• Recycling of recovered materials off-site.
• Treatment of non-recoverable waste with a focus on recovery and minimization of residues.
• Safe disposal of wastes.
• Safe handling of chemicals and products to ascertain that no site contamination or sudden releases occur.

The questions below may be used as performance measures in evaluating sustainability. The checklist items also describe recommended environmental stewardship measures: [N]

• Are preventive measures in place to avoid "off-spec" concrete, (e.g., periodic testing of scales, batch gate operation, etc.)?
• Is an operator's manual available?
• Is regular operator training provided?
• Is water conservation practiced by restriction of freshwater uses to purposes such as, truck exterior washoff, hot water production, and batch waters for high quality concrete?
• Are flow controls installed on freshwater sources?

• Are volumes of returned concrete minimized (i.e., less than 2.5 percent of total production volume)?
• Is all returned concrete either reused (precast products, road base, etc.) or recycled (reclaimed)?
• Are all air pollution control residues reused?
• Are all drum washout solids reused or recycled?
• Are settling basin sludges reused or recycled?
• Is 100 percent of the process water (drum washout, truck wash) reused?
• Is collected yard stormwater used for washdown, etc.?

• Are spills of cement and concrete cleaned up immediately?
• Is the process area paved and curbed to collect processing water for treatment and/or recycling?
• Is the pavement and curbing in good condition (i.e., no cracks)?
• Is the size of the processing area minimized and/or roofed to reduce exposure to rainfall?
• Is yard stormwater diverted from the process area?
• Are oil separators installed in truck wash areas and other areas where oil releases may occur?
• Are measures taken to ensure proper dust control during transfer of cement and fly ash?
• Are aggregate piles designed to minimize fugitive dust control (e.g., minimal surface area, storage bins, covers)?
• Are high vehicle traffic areas paved?
• Is the traffic system controlled (e.g., low speed limits, one-way traffic to separate dirty from clean vehicles)?
• Are paved portions swept to remove accumulated dust?

• If all concrete and sludges are not recovered on-site, are the materials used off-site (e.g., road base)?

• Is there a system (e.g., settling basin) for treatment of excess water?
• Does the treatment system enable pH control?
• Is the process area minimized (i.e., <10 percent of total yard area)?
• Does routine monitoring of effluent quality occur?
• Is the wastewater holding basin of sufficient volume to manage all effluent in high precipitation events?
• Can concrete fines and aggregates be removed from the basins?
• Is unusable sludge disposed of in approved facilities?
• Are admixture and other chemical containers returnable to the supplier?
• Are all chemicals no longer in use removed from the site?

• Are lead batteries, solvents, waste oils, etc., stored in secure locations?
• Are lead batteries, solvents, waste oils, etc., recycled?
• Are operating procedures for waste disposal adequately defined?
• Has management confirmed that approved facilities are used for waste disposal?
• Is all documentation at hand for transport manifests, certification of destruction, etc.?

• Are aboveground piping and valves visible and labeled?
• Are tank materials and designs as per all applicable codes and manufacturers' recommendations?
• Are spill response equipment, absorbents and personnel protection equipment provided?
• Is worker training for spill response provided?
• Are signs in place to identify contents of bulk tanks and drums?

Cracks and joints in Portland cement concrete pavement should be filled to prevent the entrance of moisture into the subgrade. A stiff broom or compressed air are sometimes used to clean cracks prior to sealing. Aphaltic and rubberized sealants are used to fill the cracks; then sand may be applied. Other subtasks associated with this activity may include vehicle operation and post-sweeping. Leaks, spills, excess emulsion and dust can release pollutants such as fuel, asphalt release agents, hydraulic fluid, oil, sediment, asphalt and rubberized sealant. Recommended environmental stewardship practices to control such discharges include illicit connection/illicit discharge reporting and removal, scheduling and planning, illegal spill discharge control, vehicle and equipment fueling, vehicle and equipment maintenance, solid waste management, hazardous waste management, liquid waste management, sanitary/septic waste management, material use, safer alternative products, spill prevention and control, and sweeping and vacuuming.[N]

The following general practices should be employed for patching, resurfacing, and sealing:

• Schedule patching, resurfacing and surface sealing for dry weather.
• Stockpile materials away from streets, gutter areas, storm drain inlets or watercourses.
• During wet weather, cover stockpiles with plastic tarps or berm around them if necessary to prevent transport of materials in runoff.
• Pre-heat, transfer or load hot bituminous material away from drainage systems or watercourses.
• Where applicable, cover and seal nearby storm drain inlets (with waterproof material or mesh) and maintenance holes before applying seal coat, slurry seal, etc. Leave covers in place until job is complete and until all water from emulsified oil sealants has drained or evaporated. Clean any debris from covered maintenance holes and storm drain inlets when the job is complete.
• Prevent excess material from exposed aggregate concrete or similar treatments from entering streets or storm drain inlets. Designate an area for clean up and proper disposal of excess materials.
• Use only as much water as necessary for dust control, to avoid runoff.
• Sweep, never hose down streets to clean up tracked dirt.
• Use a street sweeper or vacuum truck.
• Do not dump vacuumed liquid in storm drains.
• Catch drips from paving equipment that is not in use with pans or absorbent material placed under the machines. Dispose of collected material and absorbents properly.

Mudjacking is necessary for the maintenance and repair of rigid type surfacing, its associated base and any Portland concrete cement shoulders less than two feet in width. A Portland cement and pozzolan grout mixture is pumped below the slab (i.e., mudjacking) to replace lost or settled base material. Subtasks include vehicle and equipment operation, drilling, mixing, and pumping. Potential pollutant sources such as leaks, spills and concrete washout may result in the release of pollutants such as fuel, hydraulic fluid, oil, sediment and concrete. Water applied during drilling and pumping operations must be controlled to prevent unpermitted non-stormwater discharges. Recommended environmental stewardship practices to control discharges include: illicit connection/illicit discharge reporting and removal, scheduling and planning, illegal spill discharge control, vehicle and equipment fueling, vehicle and equipment maintenance, solid waste management, liquid waste management, sanitary/septic waste management, concrete waste management, material use, safer alternative products, spill prevention and control, sweeping and vacuuming and water conservation practices.[N]

Spalling (i.e., chipping of Portland cement concrete surfaces), slab cracking and settlement are common problems associated with Portland cement concrete pavement that require repairs. Subtasks include vehicle operation, repair and cleaning (may include use of a compressor, jackhammer or sawcutting), curing and the disposal of removed materials. Leaks, spills and concrete washout may cause pollution from fuel, hydraulic fluid, oil, sediment and concrete. Water applied during curing operations should be controlled to prevent unpermitted non-stormwater discharges. Recommended environmental stewardship practices include: illicit connection/illicit discharge reporting and removal, scheduling and planning, illegal spill discharge control, vehicle and equipment fueling, vehicle and equipment maintenance, solid waste management, hazardous waste management, liquid waste management, sanitary/septic waste management, concrete waste management, material use, safer alternative products, spill prevention and control, sweeping and vacuuming and water conservation practices.[N]

For concrete installation and repair also:

• Schedule asphalt and concrete activities for dry weather.
• Take measures to protect any nearby storm drain inlets and adjacent watercourses, prior to breaking up asphalt or concrete (e.g. place san bags around inlets or work areas).
• Limit the amount of fresh concrete or cement mortar mixed, mix only what is needed for the job.
• Store concrete materials under cover, away from drainage areas. Secure bags of cement after they are open. Be sure to keep wind-blown cement powder away from streets, gutters, storm drains, rainfall, and runoff.
• Return leftover materials to the transit mixer. Dispose of small amounts of hardened excess concrete, grout, and mortar in the trash.
• Do not wash sweepings from exposed aggregate concrete into the street or storm drain.
• Collect and return sweepings to aggregate base stockpile, or dispose in the trash.
• When making saw cuts in pavement, use as little water as possible and perform during dry weather.
• Cover each storm drain inlet completely with filter fabric or plastic during the sawing operation and contain the slurry by placing straw bales, sandbags, or gravel dams around the inlets.
• After the liquid drains or evaporates, shovel or vacuum the slurry residue from the pavement or gutter and remove from site. Alternatively, a small onsite vacuum may be used to pick up the slurry as this will prohibit slurry from reaching storm drain inlets.
• Wash concrete trucks off site or in designated areas on site designed to preclude discharge of wash water to drainage system.

Using Portland cement-containing products requires prevention of the discharge of high pH liquids to creeks, streams, and other water bodies, or in places where it might eventually reach creeks and streams.[N]

• Be aware of local environmental sensitivities around the job site. Know where streams and street drains are in order to avoid discharging harmful materials.
• Install continuous pH monitoring devices on effluent outflow. If the pH goes outside of the range of 6.5-9.0, have a means of treating the effluent prior to discharge.
• Grade the site to prevent storm runoff from leaving yard.
• Have an adequately-sized effluent pond.
• Have reliable means of testing pH on site and personnel trained in the measurement of pH (see How Can I Measure pH?).
• Wash chutes off in an area with permeable ground, and away from any subsurface drains (tile fields, perimeter drains, etc.), streams or storm drains. Although New Jersey DOT specifically states " Concrete truck washout onsite is prohibited outside designated areas. Designated washout areas shall be lined and bermed to prevent discharges to surface and ground water. Hardened concrete from concrete truck washout shall be removed and properly disposed of."[N]
• Have some means of containing the wash-water for disposal back at the plant if there is no appropriate place to wash the chute at the job site.
• Use equipment with wash water containment systems.

In the event that conditions at the work site change, a back-up plan is needed as the user should know ahead of time what to do if this happens. The following are practices to lessen the damage a spill of alkaline material might do to a fish-bearing waterway: [N]

• Have on hand the names and telephone numbers of vacuum pumper truck companies that can come and clean out the catchbasins of street drains, or clean up material spilled on the ground (look in the Yellow Pages under "septic tanks - cleaning and removal"). Many DOTs and municipalities also have vacuum trucks.
• Have on hand some means of blocking storm drains or other potential routes to any water bodies.
• Have on hand some means of checking the pH of spilled material.