Making connection of drain or sewer line with existing manhole including breaking into and making good the walls, floors with cement concrete 1:2:4 mix (1 cement : 2 coarse sand : 4 graded stone aggregate 20 mm nominal size) cement plastered on both sides with cement mortar 1:3 (1 cement : 3 coarse sand), finished with a floating coat of neat cement and making necessary channels for the drain etc. complete

Under the CPWD Delhi Analysis of Rates 2023 (Civil), item 19.21.2 — Making connection of drain or sewer line with existing manhole including breaking into and making good the walls, floors with cement concrete 1:2:4 mix (1 cement : 2 coarse sand : 4 graded stone aggregate 20 mm nominal size) cement plastered on both sides with cement mortar 1:3 (1 cement : 3 coarse sand), finished with a floating coat of neat cement and making necessary channels for the drain etc. complete : For pipes 250 to 300 mm diameter — is derived from 6 priced inputs for one connection and works out to ₹922.40 per one connection after water charges, GST, CPOH and cess. The full build-up is below.

From the CPWD Delhi Analysis of Rates 2023 (Civil), Volumes I & II, printed page 1748. Reference only — CPWD amends rates through correction slips between editions, so verify against the official source before pricing a bid.