Black gritty stuff in drinking water!

We have just had an extension built, into which a new kitchen has been fitted. We started losing pressure in kitchen taps, the American Fridge Freezer gave up the ghost dispensing water (ice not a problem!!) and now dishwasher has a water intake malfunction. After confounding our plumber we took off the filter of the tap and discovered a blockage of massive proportions of black sand like stuff! This stuff was also blocking the intake pipe to the dishwasher although, sadly we can't reach the other end of the hose as dishwasher is integrated, so it is still blocked. We called our local water board who sent someone round. He went away saying "lead" and "the worst case he has ever seen", however, despite this it will take them 10 days to come and replace the mains pipe which leads into the house and is lead. I am not convinced it is lead as the consistency is sharp like sand, black and very uniform in size and is not discolouring the water.

If anyone has a clue what this stuff could be, help and advice would be appreciated hugely.

PS work has also been done in the bathroom, not sure if there could be a link but thought I'd mention it!

Thanks

Kenners

Have any neighbours had similar problems? If not, it's not likely to be anything to do with water mains. More likely your builder somehow got a load of sand in the pipework. Can't see how it could be lead. Fit a filter on the incoming main supply just to be sure that nothing more can enter your system from that source.

Thanks

Sounds good advice to me, as neighbours don't have any problems at all!

Thanks again

Don't know if this has any relevance.

One of the early jobs I was involved with as a water engineer was the cleaning of several miles of 36" bitumen lined steel water mains from a soft water area. There was about 3/8inch of a black deposit on the inside of the bitumen lining. Main was about 30 years old. We designed a spring loaded device with rubber blades which scraped this off when pulled from access point to access point. This was washed to low points and pumped into nearest stream. (it was 30 years ago when you could get away with things like this)

The black stuff was inorganic and came off the pipe much easier when we let it dry out for a day. It was hell to get out of the pores in your skin but I don't remember if it was that gritty.

Perhaps what you have is a similar deposit disturbed during the works.