Technical Booklet B Materials and Workmanship·Page 16·2.22
District Council Powers for Testing Drains and Sewers
A district council may require prescribed tests of drains and private sewers to establish compliance with Part N of the Building Regulations, and may carry out such tests.
A district council has the power to require tests as prescribed in regulation 15 in Part A of the Building Regulations, to be carried out in relation to drains and private sewers as necessary, to establish compliance with Part N of the Building Regulations. These prescribed tests may also be carried out by that district council.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/Technical Booklet B - Materials and Workmanship.pdf