Sheep, it is said 'May Safely Graze' according to Johann Sebastian Bach. This morning saw proof of this as Malcolm and I enjoyed a sunny walk around Mapperley reservoir.
Returning home, we walked past the group of six man-made ponds near our estate which together make up slurry settlement pits. Sounds nasty, but the idea is a good one. Waste water and slurry from the farms around the area, is pumped into the top two ponds and is allowed to settle as it fills them.
Water fills the last, lowest two ponds and is allowed to settle some more becoming beautifully clear by the time it reaches the end of the system. At this point, the water is pumped back into the Nutbrook stream system. A brilliant system which works very well with the minimum of fuss. You just don't want to be around when the pits have to be dredged to clear them out!