'fternoon all.......My workshop is not connected to mains drains, so all waste from the site (which is two large houses, four workshops & twelve portacabins which are farmworkers accommodation) drains into three holding tanks and is pumped up to a soakaway. I'm putting about 1000 litres per week of methy/glycy wash water into this, and am wondering if I am doing the system any damage. Chatting with the landlord this morning, he told me that he has had some problems with blockages, and whilst he wasn't blaming me, he has never had this problem before. Any thoughts?