Tank Cleaning
The problem
The pumps in a large 16m wide and 20m deep inlet pumping station at a wastewater treatment works were frequently blocking due to the volume of silt and screenings in the wet well.
The solution
The thick layer of sludge, screenings and silt in the wet well was first removed using a DISAB vacuum tanker working from the top only. As the levels of sludge, screenings and silt in the tank decreased a safe working area was cleared in the tank. Once the tank was deemed to be safe to enter after gas testing, two confined space trained operators were lowered into the wet well using a man riding basket and mobile crane. A further mobile crane and man riding basket was on standby at all times. When the operators were safely on the base of the well, the remaining material was broken up using the JetVac’s jetting hose and removed using the DISAB’s vacuum hose. The material removed from the well was screened using the mobile Screening and Dewatering Plant and the screened water was pumped back into the site drainage. The silt and debris was deposited into an eight yard builders skip for disposal offsite using our skip vehicle.
Anaerobic Digestion Cleaning
The problem
The mixers in a customer’s Anaerobic Digester had stopped working due to the volume of solids that had built up in the tank and also the customer needed to repair several small holes in the tank. To repair the mixers and the holes in the tank the tank needed to be emptied and cleaned.
The solution
The material in the Anaerobic Digester was broken up using a fire hose connected to a wash out onsite and then vacuumed out of the tank using one of our DISAB Centurions. The wet material was then blown from the Disab into our mobile screening and dewatering plant which processed the material and deposited the dry material into a commercial bin at the rear of our mobile screening and dewatering plant. The customer removed the commercial bin using a forklift and tipped the dry material into their dry waste bays onsite for disposal. Our mobile screening and dewatering plant pumped the screened wastewater back into the customer’s process. Once the tank had been emptied it was given a final clean using the fire hose connected to a wash out.
Pipe Cleaning & Surveying
The problem
The highway drains were overflowing during periods of significant rainfall, causing localised flooding and the public footpaths and verges that the highway drains ran underneath were due to be replaced.
The solution
A length of 3400m of mainly 150mm diameter highway carrier drain and associated road gullies and lateral connections were cleaned and surveyed using an Andidrain sewer cleaning recycler and CCTV Unit. The CCTV surveys identified some lengths of the carrier drain as being in poor structural condition and some lengths having root ingress. Root masses were cut and removed using a warthog and flail, followed by a complete clean of the system. To prevent root regrowth and further deterioration in the condition of the pipe, defective sections were lined using our UV (Ultra Violet) Pipe Lining rig, with lateral connections reopened using our remotely controlled robotic cutters.