September’s call of the months goes to a customer in Derbyshire. who had a recent repeated issue with rats entering the fabrics of the property. The property is a Detached property, well maintained with no obvious external defects. Everything was where it should be, no clutter, clean and clear environment… nothing untoward to attract rats to the property, yet they had returned.

Previous to my involvement another PCC had carried out assessments and advised that there was a CCTV survey carried out of the foul drainage system. A large amount of backfill debris had been noted within a manhole located at the rear corner of the extension, enough to cover the entire pipework and the chamber benching… (Clue). In total there are three chambers located within the boundary of the property.

The direction of flow was noted and it was confirmed that the chamber was a ‘Public Sewer’ and the asset of the Local Water Authority (Seven Trent Water) this is because the sewer waste from the neighbouring property passes through on its way to the main sewer system in the highway.

** Surfaces or boundaries are not relevant, it is where the drainage system becomes shared is where ownership from private to public takes place. **

The LWA (Local Water Authority) were contacted and a CCTV survey was carried out by one of their contractors. A survey was carried out to completion and it was confirmed that there were NO defects within the drainage system, a advisory was noted that there was a capped of line where some drainage had been altered when the rear extension had been build. It was advised that the line entering the chamber was to be bunged off which was carried out promptly.

Yet the rats returned.. The property is in a good state of repair, there are no obvious defects, the drainage has been inspected and no defects were noted..

A problem I have encountered many times when a CCTV survey has been carried out by LWA’s or their contractors is that surveys are often carried out with a view to identify drainage defects that could or would obstruct flow. It is what is viewed on the screen which is noted, it is what the camera node see’s that is documented.

If there are no defects noted within the pipework then the report is given that the drainage system is not the cause of the rat infestation, the LWA have done their survey and the problem is not theirs. this is not always the case. (Remember the Clue). My customer told me that there was a lot of stone and rubble debris within the manhole, enough that it covered the channel benching and holding up the neighbouring foul waste water.

So if there were no actual pipework defects the rubble had to come from somewhere, in this case where the manhole raising sections meet the channel benching. The debris and rubble noted by my customer was actually the backfill material from around manhole chamber itself, after the rats had breached the chamber wall their burrowing spoilt had to go somewhere, in this case the foul drain itself.

I was contacted because Rat activity had been noted within the property. So the point of entry has now been confirmed we are left with the dilemma of do we just bait the inspection chamber and not block the entry point..?

The problem being that baiting the sewer will be a endless task and we run the higher risk of more rats finding the POE and the internal infestation increasing also increasing the risk of my customer checking herself into a mental health institution (She wasn’t handling this too well)

Or…..

Do we bait and block the point of entry, essentially entombing the rodent with the hope it will consume the baits and expire quickly just the other side thus not decomposing within the dwelling itself.. Yes, there is the animal welfare act to be observed in regards to causing unnecessary stress and harm to the animal, however we also have to apply common sense sometimes as well and in my opinion my ‘Human’ customers health was far more important than that of the Rat(s) so we blocked the hole. …!!

There is always the chance that we would have blocked it out anyway as it had not been heard for a day or so… Nope.. It was inside..

and it found another way out….

A few days after the initial blocking and now confirmed entombing of the Rat noises were once again heard, on returning and lifting of the manhole lid my repair was still solid. The rat appeared to have attempted to re-enter the drainage system, found it blocked, backtracked, carried out some further excavation works and exited under the concrete surround which encases the chamber lid above the top raising section.

While this was brittle enough for the Rat to take advantage of for easy excavation it was not obvious to the eye as the previous inspection had not highlighted concerns. Again, further baiting and some extra rapid mix to block this area.

The fact is that the inspection chamber is the responsibility of the local water authority as it is their asset under the ‘Transfer of Private Sewers Regulations 2011’ and the fact is that it is their inspection chamber to correct long term. All works carried out by myself have not compromised the structural integrity of the manhole construction. My blocking of the points of entry and exit are not deemed to be repair works.

I have used the legislation ‘Public Health Act 1936 as regards to the destruction and removal of Vermin’ the very same act which covers the transfer regulations. Once I am satisfied that there is no longer a vermin issue within the property and all necessary works have been carried out to completion then a further report will be submitted to the local water authority for their review as to a more secure and permanent repair to the problem inspection chamber.

After all, it is theirs to maintain, I have merely applied common sense and stopped the rats from taking up residence within the property. Maybe if a survey wasn’t just to look at a screen but to actually use eyes then they would have seen what i did. It’s obvious when you know what you are looking for.

Rattraxs Pest Control carry out both CCTV surveys and close inspections for rats, I may be a ‘Certified’ NADC (National Association of Drainage Contractors) Surveyor but I still always use my eye’s and common sense and do not just go on what the screen shows.. Sometimes the ‘Old School’ ways are still the best ways.

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