PROBLEM

Remtech was engaged to clean oily sand deposits from engine terminal sand pits and wastewater sewer.  Sand pits were cleaned by conventional hi-rail vacuum truck extraction (two-thirds of this project).

Sand and lube oil had accumulated in 1,000 ft of a 24-inch ductile iron wastewater pipe over a decade presenting a unique cleaning problem.  Deposit depths ranged from 4" to over 18-inches.

SOLUTION

Initial attempts to clean the sewer via conventional jetting techniques proved non-productive  due to the weight of deposits, long fluidization distances between manholes, and sag points in the line.

Two additional manholes were installed to shorten cleaning distances to

300 ft. A 90o elbow clog point (without a manhole) was removed). Remtech developed a proprietary horizontal hydroexcavation technique VacuJetTM . VacuJetTM is a combination jetter/cutter head attached to a four-inch vacuum line to fluidize and evacuate solids over long distances.

A hose glide system was attached to manholes and pipe/manhole penetrations to negotiate 90 degree directional transitions to minimize friction and maintain solids flow. A winch with a high tensile strength synthetic line dragged the cutter head and vacuum hose through 300 ft sewer sections. An estimated 11,750 gallons of solids were removed using this method.

COST/BENEFITS

1. Conventional jetting cleaned approximately 200 ft of 24” sewer in 15 days.

2. VacuJetTM (developed on this project by Remtech) cleaned 800 ft of sewer in four (4) days. This method should substantially reduce sewer cleaning costs for heavy solids, long distances between manholes, and inadequate sewer slopes.

VACUJET Operations at Lead Manhole

Oily Sand Deposit in 24" Pipe Prior to Cleaning

24" Pipe During Cleaning Operations

Remtech VacuJET Pressurized Water Jets

Breakup and Fluidize Solids

Location: Central Georgia

Client: Major Railroad

Contract Amount: $224,000

250 ft VacuJet Hose Extraction After Completion of Sewer Cleaning