The Problem: A Ditch and Two Culverts Blocked with 100 Tonnes of Silt
Our services were required to maintain the drainage system of an estate in Birdham. Two culverts and a ditch had become blocked with a dangerous level of silt.
The ditch had become over grown with tree roots and weeds. The culverts were becoming clogged with silt. The maintenance was required as part of flood prevention work in the county. The ditch ran along the side of the housing estate and was essential to their drainage in the face of a large amount of rainfall. Without this work, flooding would be a serious danger for these properties.
Following our site visit Hydro Cleansing established that the following were required to complete the job:
Three areas were blocked: a ditch 85m in length was blocked with approximately 80 tonnes of silt waste; one 450mm culvert that was 65m in length and one 450mm culvert which was 100m in length. The amount of waste in the culverts was confirmed on completion of the job as 13 tonnes. A 20,000 litre bulk tanker brought the water supply for the high pressure jetting work which was required to dislodge the silt and mud from the tree roots in the ditch. The water was also necessary to jet through the culverts. The work was completed over 5 days. The CCTV team were there for 2 days completing pre work and post work surveys.
The 2 man team worked in the ditch, jetting the silt clear of the roots, while maintaining the essential tree roots.
The powerful suction of the super combination unit at 3500CFM meant that the silt was sucked away into the waiting articulated bulk tanker. The waste was removed and disposed of each evening at Hydro Cleansing’s own wet waste disposal plant.
Hydro Cleansing’s Result
Clearing the 85m ditch, 65m and 100m culvert and removing and disposing of 100 tonnes of waste was completed on time and meant the risk of flooding was significantly reduced.
As London smoothly continued its business, Hydro Cleansing moved into the dirty underworld of a pump station in West London. After a free site survey HCL established that four screens within it were on the verge of becoming blocked.
Four vast 4m high screens were located within a 20m deep shaft. This would be an overwhelming job for most companies. Megatron’s force was the only answer!
To accompany the beast, HCL sent an articulated bulk tanker to hold the waste and a five man confined space team. The team comprised of one topman, a two man working team and a two man rescue team. With extendible hand lances, the engineers were winched into the large space to blast the rag off even the highest parts of the massive screens. Not only vacuuming the silt and rag 20m vertically, Megatron’s phenomenal jetting force was required to cut the rag loose. A hydrant near the pump station provided a good water flow which was then blasted though the beast’s powerful hoses. These screens were fixed in place. Our confined space team worked using the jetting equipment and crow bars to chop through the rag. Lights powered by Megatron’s generator and the lights on the engineer’s hardhats lit the gloomy space.
The screens are in the pump station to act as grates to filter the solid waste, allowing the liquid waste through. Having not been cleaned for a number of years, the silt was almost at dangerous levels. Rag and solid waste caked the giant grates. Clearing them efficiently was essential. The silt that had built up behind it had to be removed and disposed of immediately. The utility company, who we were working on behalf of, closed the sewer’s pen stocks (large gates that act as valves regulating the flow of the sewer) temporarily which allowed the work to go ahead. A storm hit after the first day. The sewer had to be allowed to flow. Our team returned after the storm’s flow had abated and finished the remaining screens.
The engineers had compressed air breathing equipment on site in case it became necessary. Our confined space engineers were winched down into the space. They were equipped with masks and air bottles in case of gas emergencies and we had supplies of compressed air and hose with us in case it was necessary. The team could wear masks and have air pumped from above. Thankfully, this turned out not to be necessary.
Before, during and after cleaning the pump station screens:
We were delighted to complete this job for one of the South East’s largest utility companies. Our engineers’ hard work and the almighty force of Megatron allowed them to complete the job in three days!
Our tankers were up to some awesome team work yesterday!
Again we were out protecting our country’s motorways. The job was to clear a culvert of a build-up of embedded silt. The estimate was 30 tonnes of waste!
This was a large scale job involving a fantastic team and some of our flagship tankers. Our Super combination unit Rainmaker was there providing the hard core power for the operation. Our artic tanker which is nick named ‘Jack the giant slayer’ stored the waste that Rainmaker vacuumed. Another bulk tanker, our confined space team and a welfare unit made up the rest of the fleet.
Due to the nature of the waste, our team implemented a strategy of lowering the flow of water through the culvert to allow the confined space engineers into the space to shovel the shingle and silt into Rainmaker’s vacuum. They made a dam at the far end of the culvert and our combination unit was used to divert the remaining water flow from the culvert into a ditch beyond. It would naturally have flowed there from the culvert.
A 4” vacuum hose maintained the low water level allowing the confined space team access to the culvert. The larger 6” hose removed the large pieces of silt.
Our confined space engineers worked flat out to funnel the silt into the vacuum hose. You can see some of the silt is the size of golf balls. The vacuum hose sucked them away into our tankers.
Thankfully we have a welfare unit that we bring to these kinds of jobs. A warm kitchen, toilet and shower mean our engineers can have a short break on site and return to their work without much disruption. It saves driving covered in mud to the nearest greasy spoon for a cup of tea after shovelling mud for hours.
Good honest work was done! Preventative action against flooding was taken. Our work made the light at the end of the tunnel possible.