Changes

*To permit access by cameras or cleaning apparatus, 90 degree pipe couplings must not be used in subterranean underdrains. Instead 2 x 45 degree couplings, or 3 x 30 degree couplings should be used (see figure to the right).  

*To permit access by cameras or cleaning apparatus, 90 degree pipe couplings must not be used in subterranean underdrains. Instead 2 x 45 degree couplings, or 3 x 30 degree couplings should be used (see figure to the right).  

*For the same reason, dual walled perforated pipes with smooth internal walls are highly recommended to reduce the potential snagging of maintenance equipment.   

*For the same reason, dual walled perforated pipes with smooth internal walls are highly recommended to reduce the potential snagging of maintenance equipment.   

*The recommended distances between clean outs is based on advice for filter beds in the Ontario Building Code<ref>Province of Ontario. (2018). O. Reg. 332/12: BUILDING CODE. Retrieved February 23, 2018, from https://www.ontario.ca/laws/regulation/120332</ref>. However, the access capabilities of difference apparatus and contractors varies and designers are advised to take advice from maintenance operators in this matter.  

*The recommended distances between [[Wells|clean outs]] is based on advice for filter beds in the Ontario Building Code<ref>Province of Ontario. (2018). O. Reg. 332/12: BUILDING CODE. Retrieved February 23, 2018, from https://www.ontario.ca/laws/regulation/120332</ref>. However, the access capabilities of difference apparatus and contractors varies and designers are advised to take advice from maintenance operators in this matter.  

*[[Wells]]

*[[Wells]]