Laserfiche WebLink
<br />. <br /> <br />e <br /> <br />.- <br /> <br />(1) Connections between public sanitary sewers and the manhole <br />shall adhere to the following criteria. <br /> <br />(a) The elevation of the flowline of the discharging <br />sanitary sewer shall match the elevation of the <br />flowline of the receiving sanitary sewer for both <br />equal and unequal pipe diameters. <br />(b) Drop manholes are allowed. A drop connection or <br />drop manhole is required when the difference in <br />elevation between the effluent flowline and the <br />influent flowline is greater than 36 inches. <br /> <br />D. Manholes should be located as to minimize or eliminate the inflow of storm water into the <br />sanitary sewer. The top of manhole rim shall be set a minimum of 6 inches above the <br />surrounding finished grade when the manhole is not in a paved roadway. Sealed <br />manholes are required on all newly constructed manholes within the 1 OO-year flood plain. <br />Vented manholes are required a minimum of every 800 feet when not located in the <br />100-year floodplain. Under no circumstances shall the elevation of the top of rim of a <br />sanitary sewer manhole be below the 100-year base flood elevation for the area it is being <br />built in. <br />E. Manholes shall be constructed in accordance with the Standard Details where applicable. <br />All manholes shall include rubber seals precast into the manhole for pipe inserts or 3M <br />Scotch Seal 5600 and Oakum at all pipe connections (no Fosroc or cement) or approved <br />equal. Precast manholes shall incorporate a boot-type connector for sanitary sewer <br />diameters up to 24 inches. For sanitary sewer diameters greater than 24 inches, utilize <br />either the boot-type connector if available or an integral gasket. <br />F. Steps in manholes shall not be allowed. <br />G. All manhole adjustments shall be made with precast concrete rings when an additional <br />precast vertical section is too large. <br />H. All manholes shall be tested by the construction contractor and results provided to the <br />City of La Porte before being accepted by the city for maintenance. The City of La Porte <br />reserves the right to require retesting of manholes if there is reason to question the results. <br />All manhole testing shall comply with or exceed the procedures and qualifications listed <br />in Texas Administrative Code, Chapter 317, Section 317.2(c)(5)(H). <br /> <br />L. Lift Stations <br /> <br />I. Lift station design and construction drawings as wen as design requirements and <br />pertinent data shall be sealed by a Professional Engineer registered in the State <br />of Texas and submitted with the construction drawings for review by the City. <br />2. Lift Stations should be considered only when a gravity system cannot be <br />achieved from both an engineering and an economic standpoint. Lift stations <br />should only be considered with prior approval from the City of La Porte or <br />where the lift station is designed to be temporary in nature. <br />3. Lift station controls shall be enclosed and fenced in such a way to deter <br />unauthorized operation, vandalism and/or terrorism. <br /> <br />a. Controls and equipment shall be approved by the City. Pumps shall be <br />submersible type manufactured by Hydromatic, or Flygt, or approved <br />equal. Pump controls shall be manufactured by E.G. Controls or <br />Consolidated Electric, or approved equal. <br /> <br />4. Wet Wells <br /> <br />a. .Provide adequate clearance between pumps so as to easily facilitate <br />retrieval of a pump. <br /> <br />Sanitary Sewcr Design Criteria Page 10 of 11 <br />