Permits & Development - Encroachment(EP)/Driveway(DW) Permits - 2007_EP-07-301 thru EP-07-400_ - EP-07-352

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20-2.25 BACKFLOW PREVENTERS • Backflow preventers shall be one of the reduced pressure principle devices as specified in these specifications and the special provisions. • Backflow preventers shall be factory assembled and shall include 2 check valves, one pressure differential relief valve,2 shut-off valves and 4 test cocks. Backflow preventer and valves shall be the same size as the pipeline in which they are installed,unless otherwise shown on the plans. • Backflow preventer shut-off valves shall be manufactured from iron or bronze and shall be either resilient wedged gate valves, resilient seated and fully ported ball valves, or resilient seated butterfly valves. Threaded type shut-off valves shall be provided with a union on one side of each valve. Unions shall be brass or malleable iron. Section 20-5.03J, "Check and Test Backflow Preventers,"of the Standard Specifications is amended to read: 20-5.03J Check and Test Backflow Preventers • Backflow preventers shall be checked and tested for proper operation by a certified Backflow Preventer Tester. The tester shall hold a valid certification as a Backflow Preventer Tester from the local governing authority in which the device to be tested is located. The local governing authority shall be the county,city or water purveyor having the governing authority over testing of backflow preventers involved. If the local governing authority does not have a certification program for Backflow Preventer Testers,the tester shall have a certificate from one of the following: A. The American Water Works Association. B. A county which has a certification program for Backflow Preventer Testers. • Tests for proper operation shall conform to the requirements of the governing authority. • The Engineer shall be notified at least 5 days prior to testing backflow preventers. • One copy of the test results for each backflow preventer tested shall be furnished to the Engineer. • Backflow preventers,installed by the Contractor,failing required tests shall be repaired at the Contractor's expense. SECTION 27: CEMENT TREATED BASES Issue Date: January 5,2007 The first paragraph of Section 27-1.02, "Materials,"of the Standard Specifications is amended to read: • Cement shall be Type II portland cement conforming to the provisions in Section 90-2.01A, "Cement." The third paragraph of Section 27-1.02, "Materials,"of the Standard Specifications is amended to read: • Aggregate for use in Class A cement treated base shall be of such quality that when mixed with cement in an amount not to exceed 5 percent by mass of the dry aggregate and compacted at optimum moisture content, the compressive strength of a sample of the compacted mixture shall not be less than 5.2 MPa at 7 days,when tested by California Test 312. The fourth paragraph of Section 27-1.02, "Materials,"of the Standard Specifications is amended to read: • Aggregate for use in Class B cement treated base shall have a Resistance(R-value)of not less than 60 before mixing with cement and a Resistance(R-value)of not less than 80 after mixing with cement in an amount not to exceed 2.5 percent by mass of the dry aggregate. SECTION 28: LEAN CONCRETE BASE Issue Date: January 5,2007 The first paragraph of Section 28-1.02, "Materials,"of the Standard Specifications is amended to read: • Cement shall be Type II portland cement conforming to the provisions in Section 90-2.O1A, "Cement." The sixth paragraph of Section 28-1.02, "Materials," of the Standard Specifications is amended to read: Contract No. 10-0M7104 19