1) Connections of service laterals to existing sewers shall be made watertight. Connection shall be made where possible to existing tees or wyes previously installed and plugged. In all cases, the integrity of the existing tee or wye shall be verified by Public Works prior to connection.
2) Where tees or wyes for connection are absent or unusable, connection of service laterals into existing sewer lines shall be made with approved couplings or service saddles. Taps shall be installed without protrusion into or damage to the existing sewer, and shall result in a watertight connection.
3) Service lateral connections to existing AC pipe shall be with approved service saddles. Connections to all other types of existing pipes shall use Insert-a-Tee type couplings. A note shall be added to the drawings stating that the coring machine for Insert-a-Tee couplings shall be anchored in accordance with the manufacturer's recommendations.
4) As a condition of connecting to and/or extending sewer mainlines, the design shall include verification that the existing sewer is in adequate condition and with adequate capacity to handle the new flows. This shall include verification of existing sewer slopes downstream of the connection point (as part of the design topographic survey), and cleaning/TV inspection of existing mainlines which meet any of the following conditions: (a) existing or design slopes less than 1.0% or (b) have had a history of flow or maintenance problems, or (c) end with mainline cleanouts. Costs for cleaning and TV inspection are the responsibility of the developer. Unless otherwise approved in writing by the City Engineer, this survey verification and TV inspection shall be done as part of the design process (approval by the City to defer this pre-design TV inspection work shall not relieve the Developer and/or his contractor of the responsibility to correct problems subsequently discovered). The design shall include provisions to correct any adverse grade conditions, broken/obstructed pipe or other conditions found in the existing sewer which, in the opinion of the Director, may cause sewer backups or significant maintenance issues upon extension of the mainline and connection of additional services. Any corrections of adverse grade conditions shall occur prior to extending the mainline or setting new manholes.
b. Manholes over Existing Sewers.
1) Manholes constructed over existing sanitary sewers shall conform to the requirements of OSSC (Manholes Over Existing Sewers). The existing pipe shall not be broken out until after the completion of the manhole test. Notes to this effect shall be placed on the construction drawings.
c. Maintaining Sanitary Sewer Flows. The construction of sewer improvements that impact existing sewers shall address the following, including notes on the drawings.
1) All existing sanitary sewer system components shall remain in service through the construction operations unless specific exceptions are approved in writing by the Director, and written approval from each affected property owner.
2) Sewer service from upstream and affected properties must be maintained unless such written approval is granted. The methods used to maintain sewer flows shall be the Developer’s responsibility, subject to approval by the City Engineer. Required methods of conveying sewer flows may include, but are not limited to, bypass pumping, use of flow through plugs with periodic release of sewage flows, etc. The bypass system shall be capable of conveying flows when the sewers are flowing full. Normal unrestricted flows shall be restored at the end of each work day. Bypass systems left in place or operated outside normal working hours shall be monitored continuously by the Developer and contractor unless alternate arrangements proposed by the Developer and Contractor are acceptable to the City Engineer (ie. high level & pump fail alarm callouts, etc.). The Developer and Contractor shall provide for City review all submittal information required to demonstrate compliance with these requirements.
3) Contractor shall be responsible for all costs related to cleanup, damages and fines resulting from any sewerage spill or overflow associated with any methods used to convey sewage flows during construction.