8A Inflow and Infiltration Update

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ta calculate the number of galfons that have passed through the site d�ring a particular period af time. The firsi step in using these data is to calibrate the existing pumps to determine an accurate pumping rate. �. Projeck potential source(s) based on flow data to deiermine typ�s of additional investigation methods ta use. 6. Cond�act additional investigation A. Smoke testing. This pracedure is designed to icientify direct ir�flow type sources such as low lying manhole covers, roof drains, catch basins and area drair�s. B. Physical survey. This procedure invoives physically opening and 'mspecting each manhole from the grnund surface to identify deficient adjusting rings, manhole barrel joints or wall leakage, and pip� penetration joint leakage. C. Internal tefe�ising. This procedure invoi�es cleaning the sanitary sewer segment to remove as much debris and sediment as possibEe and then sending a speciaily designed television camera down the line to view and video tape the condition of th� pipe under grour�d. The tele�isian ir�spection typically identifes structural pipe probEems including open and leaking joints, colEapsed pipes, poor quality service connections, and broken pEpes, in addition to I/T defects such as leaking joints and leaking or running service conr�ections, D. Surr�p pump inspection. This procedure involves actually entering each home or b�ilding in the selected area ta inspect the baseme�t for sump purr�ps that may be connec�ed to the sanitary sewer. The "inspector" campletes a standard form and �e[Is the bui�ding owner if their s�mp pump is correctiy connected to discharge outside or illegally connected io the sanitary sewer. If tf�e pump is i[legally connected, the property owner has an opportunity to correct the siivation and ha�e the property re-inspected to appro�e the instaElation. Sump pump inspections can require a significant labor effort to maice appointments and complete ti�e ac�ual in E�ome inspeciion. E. Foundation drain (or leaking service line) inspection. This procedure is difficult and can be highly invasi�e in certain property cases. Faundation drains that are directly connected to the sani�ary service la�eral or �eaking service la�eraE lines cannot be easily observed or inspected. Small diameter television cameras have been de�eloped that can be pushed down a 4 inch diameter sewer service pipe frorn t1�e b�ilding basement to the sewer main. However, no� every buildir�g has plumbing t�at wi[I allow the entry of the tele�ision camera. in some cases, a new cleanout must be i�tstalled to pro�ide access for tf�e camera. This can require breaking a hole in the concrete basement floor to install the new cleanout. Portions of the sewer service line can sometimes be inspected by a small rernote camera that extends up the sewer service from t�e main inspeciian camera in the street sewer. This remote camera can be effecti�e at viewing the pipe condition in a portion of the sewer service lir�e, but the length af tra�el is limited and some defects can effectively block the camera and preven� access for �iewing. identification of directly connected foundation drains and leaking service lines on pri�ate property is a difficuft and potentialfy expensive task that is appropriaiefy left to the end investigatian list. 7. Throughout the project it is impartant to compile and update a data base of defects and projected rehabilitation methods and costs to ultir►�ately prepare a priority listing of rehabiiitatior� req�ired to correct the problems. ��Metro-inet�ardenhills�PR&P11J�Engineering�1&1�6.9.Q$ Council Update�Ciry_CR]^Memarandum re iT Plan Ob 04 2448.doc 2of3