Tow Law Foot and Mouth Burial Site – County Durham – England.

We had previously approached DEFRA at Tow Law with a view to using Bio-10V to control odour at the burial site and had been given approval to conduct a trial.

The trial was to take place on one burial pit approximately 150 long x 30 meters wide x 10 meters deep. This pit is presently about 80% full and contains 24000 sheep, cattle and pig carcasses. BOD in excess of 20000 mg has been experienced.

The pit is lined with sheeting and has 3 concrete vertical columns to enable leachate (all the blood/bodily fluids) to be pumped out to a holding tank. Thereafter, it is taken by tanker to a waste water treatment plant in Newcastle (about 50 miles away).

On arrival at the site, all the carcasses are dumped on a large concrete apron where they are literally flattened by driving over them with a front end loader. The cattle are ‘spiked’ with a heavy forklift truck to empty all stomach contents. This is not a place for the faint hearted.

The carcasses are emptied into the pit, covered in straw and plastic sheeting and a layer of earth about 500mm thick before the next carcasses are laid. The pit is now full to about 2 meters from the top and about 120 meters in length. The last carcasses received were about 2 weeks ago and the odour control consultants, MEL, have now managed to bring the odours under some sort of control.

They have been using Diox (Chlorine Dioxide) to suppress odour and also have a sprinkler system around the site, which is sending out fine jets of a pine smelling deodorant. They are not permitted to spray Diox as it is toxic, so it has to be poured onto areas where the odour is worst.

About 4 weeks ago, the pit had been bubbling on the surface with leachate but now had settled and very little surface leachate was apparent. Odour could be detected in pockets but was difficult to pinpoint except for the concrete columns, which gave off bad odours.

With OPC’s assistance, we had calculated the surface area would require 150 liters of Bio-10 mixed with 450 liters of water. This was mixed by MEL and applied with a high pressure hose. The surface of the pit was very dry, uneven soil, which was cracked with some patches of wet caused by rising leechate. These areas were heavily dosed although the whole surface area was covered.

The application took 4 hours and we twice ran out of mixture, refilling on each occasion with 100 liters of Bio-10V and 300 liters of water. In total, 350 liters of Bio-10V were used and 1050 liters of water.

At the end of the application, there was general consensus that some minor improvement had been achieved. However, as the odour problems at the time of the trial were relatively mild, it was difficult to quantify the improvement. We agreed to re-assess the next morning and, again with OPC’s guidance, decided to undertake a further application if no significant improvement could be detected.

On arrival at site the following morning, the MEL site manager advised that, the previous evening, they had a small but bad spillage of leachate during pumping at another pit. The odour was awful and he was about to dose with Diox when he decided to use Bio-10 instead. In his own words, he was amazed at how effectively and quickly the odours were controlled.

The whole site crew were now converts and on revisiting the pit we had sprayed the previous day, everyone agreed that Bio-10V had made a considerable difference. Consequently, no further spray was undertaken. We dosed a vertical column and conducted a leachate control test by spreading some on the concrete apron and spraying with Bio-10V. All of these tests proved very successful.

We later met with the MEL contracts manager who was enthusiastically encouraged by the site crew to order Bio-10V and we have now received confirmation of an order for 1 x 1000 liter tote.

Lessons Learned