Case Study | Septic tank at a care home.
We were called out to investigate a blocked drain at a care home.
Our blocked drains engineer, charging £69 plus VAT, identified the actual problem with the septic tank and stayed on-site to help manage and explain the situation. He was able to explain the emergency charges and supervise the work so our customer didn’t have to. After arranging for an emergency tanker to empty the system – which arrived within 2 hours – our blocked drain engineer made sure the customer was fully informed and understood what was happening.
Observations
We were alarmed at the number of solids, paper etc found in the drain up to and around the main building. We would usually expect to find around 5% of the waste to be solids, paper etc and the bigger volume would be 95% water.
However in this case there was more than 100% of the waste was made up of solid matter. The colour of the sewage was very black which made me suspect that there is sewage water leaking from the drain through open joints for quite some time.
Advisement
We recommended a camera survey of all the drains around the main building.
The reason is; if there is a breach in the structural integrity of the drains, such as dropped joints and cracks – caused by ground movement, old age, bad workmanship or even root penetration of pipework – wastewater may escape.
The escaping water can wash away the surrounding supporting soil, creating a gap below, which the drain may then drop into, thereby opening any crack or joint further. That increases the volume of water escaping, which in turn increases the quantity of soil being washed away, thereby creating a vicious spiral.
This is known as an undermining effect and can cause further damage to the drain running downstream, and can damage any nearby structural foundations. The longer that an undermining effect is left to take place, the greater the damage it can cause.
The existing system consists of three chambers, the first two acting as primary and secondary settlement chambers. Upon inspection, we found that the dip pipes in the first two settlement chambers had broken off, permitting solids to pass through the system, via the third chamber to the drainage field.
The evidence confirmed that the drainage field had become clogged up with solids, and was beyond repair. Following our discussions on-site, we outlined proposals to rectify the problems, and our charges for carrying out these proposed works are as follows:
Estimate for drainage works required
As per the information and the foul inspection chamber found by our manager when he visited your office, suspects we may be able to connect to the main public sewer 50 m from your property, in the main public road.
Supply and install a pumping station and a pumping main up to and into the newly installed inspection chamber 10 m from the main public sewer. This will certainly add value to the care home.
In order to estimate for a pumping station and the main drain connection, we would need to purchase on your behalf plans of the main public sewer and carry out a survey. The purchase of the plans and the survey is £250 plus vat. In addition, we will need to install a grease trap to make sure the same problems do not arise in the pumping station as have in the septic tank.
ESTIMATE for food, fat and grease trap.
- To trace the area for services and utilities.
- To excavate an area for the proposed new fat, and grease, including a food trap and lay a concrete base.
- To supply and install a large enough trap suitable to cater for your requirements as per our conversation.
- To surround the new trap in concrete.
- To backfill excavations and leave the area flat.
Our charge to carry out the above work is £3,900.00 plus VAT inclusive of labour, plant and materials. All muck away to remain on-site placed not more than 5 m away from the job.
If the customer had chosen to continue with the septic tank setup they had they would have potentially had to spend thousands more on replacing the drainage field that had become clogged and ineffective.
PLEASE NOTE: We will connect the grease trap to the new pumping station.
TANK MAINTENANCE: A huge benefit of the grease trap is the fat is kept away from the float switches, which can and does cause disruption and irretrievable damage to the pumps.
ALL PRICES EXCLUDE: Muck away prices are also subject to consent and ground conditions.
SURFACE WATER WARNING
Please note that ASL Limited is not liable for any surface water entering the system, therefore the above estimate excludes any provisions for surface water which may or may not be entering the foul water system. If surface water/rainwater can enter the tank, this can cause further problems with separation/treatment. If the water enters in a surge, such as during heavy rainfall, or a storm, the incoming water can stir up the first tank, destroying any separation that has occurred in the primary settlement chamber and or any treatment. If you suspect that this is a problem, we advise that all the drains are checked by conducting a CCTV drain camera survey, and any surface water gullies and downpipes are tested to see if they discharge into the foul drainage system.
Pumping stations in my opinion require annual emptying and servicing, as do grease traps, which also require servicing. A plan needs to be worked out and written down to ensure continued efficient working.
Please contact us on 0800 181684, to arrange to carry out this work.