Grout prevents contamination

Problem

A broken sewer line in Baltimore, Md., allowed wastewater to infiltrate voids in the mortar joints of a brick stormwater vault. Officials looked for ways to seal the leaks.

Solution

Contractors applied a hydrophilic polyurethane grout from Fox Industries/Simpson Strong-Tie. They used an airless spray pump attached to injection ports to reach the void behind the vault. As the material contacted water, it foamed, expanding up to seven times its original mass and creating a flexible, waterproof membrane. Workers patched the port holes with hydraulic cement.

Result

Once the material cured, workers could apply various skim coats to unify the vault's appearance and provide additional chemical protection. 888/760-0369; www.foxind.com.

Materials prevent corrosion, restore structures

Problem

Six force main discharge manholes in Amity Township, Pa., were severely corroded. The Board of Supervisors asked Corrosion Technology Systems to recommend a long-term solution.

Solution

SWERP of Lafayette Hill won the bid to clean, repair and seal the manholes. Workers hydrojetted the concrete structures to obtain a bonding surface, then used rotary spray equipment to apply a 1/2-inch-thick cementious layer of RestoKrete substrate resurfacer F-121 from Sauereisen and a 125-mil-thick epoxy coating of SewerGard 210RS, also from Sauereisen.

Result

The cementious lining rebuilt structural integrity and prevented inflow and infiltration. The epoxy coating protected the resurfaced manholes from future corrosion. 412/963-0303; www.sauereisen.com.

Tank cleaning technology

Problem

Agent Ryland Holmes of Virginia Public Works Equipment Co. in Ashland, Va., had municipal customers in the Tidewater area who were struggling with grease accumulating in their lift stations. They needed an effective solution that did not demand more manpower or increase the budget.

Solution

After speaking with a representative from Gamajet Cleaning Systems, Holmes scheduled a demonstration of an EZ-8 rotary impingement tank-cleaning machine configured to operate with an 80 gpm/3,000 psi combination sewer cleaner from the City of Virginia Beach Department of Utilities.

Impingement cleaning uses a concentrated jet stream expelled in a controlled circular pattern. As flow and pressure increase, the radiating force of the liquid scours the vessel and provides a cascading rinse. The spray head, positioned in a wet well for the demonstration, finished the first 360-degree cycle in 12 minutes. A 6-minute cycle followed to homogenize the grease, which was suctioned into the combination truck.

Result

The unit eliminated the need for confined-space entry. Tidewater authorities are staying ahead of grease buildups in their lift stations and providing better service to their customers. The cleaning machine works with standard jetters and combination sewer cleaners. 877/426-2538; www.gamajet.com.

Monolithic product stops I&I

Problem

A deteriorated brick manhole in a busy intersection of Palm Beach, Fla., was surcharged with groundwater and flow from an additional service line. The city needed a quick rehabilitation method.

Solution

SAK Construction of Palmetto used SprayWall from Sprayroq to solve the problem. Workers pressure-washed the manhole at 3,000 psi and applied a hydraulic cementitious mortar to create a smooth substrate. They also replaced the bench and trough to ensure a smooth transitional channel for existing flow.

To stop inflow and infiltration, workers drilled 1-inch holes at the points of intrusion, then pumped in acrylamide grout covered by a layer of mortar. They then sprayed the structure with a 125-mil-thick application of SprayWall, a monolithic product.

Results

The corrosion- and abrasion-resistant surface extended the manhole's lifespan by up to 50 years. 205/957-0020; www.sprayroq.com.

System replaces manhole chimneys

Problem

The City of Las Vegas bid out a manhole frame adjustment project on The Strip. Rehabilitating the five structures had to be done in one day between 2 a.m. and 10 a.m.

Solution

Harber Co. won the bid. Workers used the manhole chimney replacement system from Mr. Manhole. The circular cutter, powered by a skid-steer, quickly penetrated the street and removed the manhole frames in one hour. The crew rebuilt the chimneys using plastic liners and poured-in-place concrete rings.

Result

Traffic was allowed on The Strip by 9:30 a.m. 419/229-3015; www.mrmanhole.com.

Protective coating stops corrosion, infiltration

Problem

The protective coating was failing on two leachate collection manholes at an Ontario landfill, resulting in severe corrosion of the concrete and costly treatment of groundwater.

Solution

City officials hired Liqui-Force Services to rehabilitate the structures. After extensive safety preparation, workers used high-pressure water blasting to expose a solid substrate, then installed a stress skin panel from SpectraShield to eliminate corrosion and stop infiltration.

Result

Repairs to both structures were completed in less than one week. 800/284-2030; www.spectrashield.com.

Manhole insert prevents dumping

Problem

A 24-inch sewer main in the City of Glendale, Calif., had an off-street manhole vulnerable to dumping. The activity could damage and block a diversion structure immediately downstream of the manhole.

Solution

The Wastewater Division of the Crescenta Valley Water District had SewerLock install a stainless steel manhole insert. The district supplied keyed-alike padlocks. Workers rejuvenated the concrete riser rings and installed a sub-ring with anchor bolts. The inner cover releases during an overflow.

Result

The insert prevented costly damage to the downstream structure and cleanup from dumping. 408/761-5882; www.sewerlock.com.