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HomeMy WebLinkAbout262.002% 1 2.5 MIN. 1 2.5 MIN. GENERAL NOTES: 1.MINIMUM UTILITY SETBACKS AND PROTECTION MEASURES MUST CONFORM TO CURRENT CITY STANDARDS, STD. PLANS 265.00, 265.10, AND 265.20, AND OTHER UTILITY PROVIDER REQUIREMENTS. COORDINATE WITH CITY ENGINEER IN THE EVENT OF UTILITY CROSSINGS OR CONFLICTS. 2.BSM PLACEMENT, GRADING, AND CONSOLIDATION SHALL NOT OCCUR WHEN THE BSM IS EXCESSIVELY WET OR HAS BEEN SUBJECTED TO MORE THAN 1/2" OF PRECIPITATION WITHIN 48 HOURS PRIOR TO PLACEMENT. EXCESSIVELY WET IS DEFINED AS BEING AT OR ABOVE 22% SOIL MOISTURE BY A GENERAL TOOLS AND INSTRUMENTS DSMM500 PRECISION DIGITAL SOIL MOISTURE METER WITH PROBE (OR EQUIVALENT). THERE SHOULD BE NO VISIBLE FREE WATER IN THE MATERIAL. THE CONTRACTOR SHALL PLACE BSM LOOSELY WITH A CONVEYOR BELT OR WITH AN EXCAVATOR OR LOADER FROM A HEIGHT NO HIGHER THAN 6 FEET, UNLESS OTHERWISE APPROVED BY THE ENGINEER (I.E., DO NOT DUMP MATERIAL DIRECTLY FROM TRUCK INTO CELL). COMPACT BSM USING NON-MECHANICAL COMPACTION METHODS (E.G., BOOT PACKING, HAND TAMPING, OR WATER CONSOLIDATION) TO 83% (± 2%) OF THE MAXIMUM DRY DENSITY PER MODIFIED PROCTOR TEST (ASTM D1557), OR AS DIRECTED BY THE ENGINEER. 3.SEE CONSTRUCTION PLANS FOR SPECIFIC PROJECT REQUIREMENTS. NOTES: 1.AVOID COMPACTION OF EXISTING SUBGRADE BELOW BASIN. 2.SCARIFY SUBGRADE TO A DEPTH OF 3 INCHES MINIMUM IMMEDIATELY PRIOR TO PLACEMENT OF BIORETENTION SOIL MIX (BSM) AND UNDERDRAIN AGGREGATE. 3.18" MIN. BIORETENTION SOIL MIX ON BOTTOM AND SIDES TO TOP OF PONDING AREA. BIORETENTION SOIL MIX TO MEET STD. PLAN 262.60. 4.ARBORIST WOOD CHIP MULCH TO MEET STD. PLAN 262.60. 5.DO NOT USE FILTER FABRIC BETWEEN SUBGRADE AND THE BIORETENTION SOIL MIX. 6.MAXIMUM LONGITUDINAL SLOPE (ALONG DIRECTION OF FLOW) OF BIORETENTION SWALES SHALL BE 6%. 7.WHERE NOT CONFLICTING WITH REQUIRED CLEARANCES OR UTILITIES, TREES MAY BE LOCATED IN BIORETENTION. REDUCE BOTTOM WIDTH TO 6 INCHES MINIMUM AND INCREASE SIDE SLOPE TO 1.5H:1V ADJACENT TO TREE. TREES TO BE LOCATED ONLY OUTSIDE OF LINER FOR LINED FACILITIES. 1.5 1 FOR EDGE TREATMENT OPTIONS, SEE STD. PLAN 262.20 ROADWAY OR PARKING LOT TRANSITION ZONE SOIL, SEE STD. PLAN 262.20 2"-4" DEPTH ARBORIST WOOD CHIP MULCH, SEE NOTE 4 OVERFLOW TO STORM MAIN SIDEWALK, LANDSCAPING, DRIVEWAY, OR PAVEMENT ANGLE OF REPOSE DESIGNER TO SPECIFY WATER STORAGE ELEVATION TOP OF BANK ELEVATION SCARIFIED AND UNCOMPACTED SUBGRADE, SEE NOTES 1 AND 2 OVERFLOW STRUCTURE PER STD. PLAN 262.40 UNLESS SPECIFIED OTHERWISE BIORETENTION SOIL MIX (BSM), SEE NOTE 3 GRAVEL BASE, SEE STD. PLAN 262.40 SEE STD. PLAN 262.20 1" 6" 2"-12" PONDING DEPTH 18" MIN. SEE STD. PLAN 262.20 BOTTOM WIDTH MIN. 18" 6" MIN. FREEBOARD 12" MIN. ABOVE SEASONAL HIGH GROUNDWATER OR HYDRAULICALLY RESTRICTIVE LAYER SIDE SLOPE AT TREE, SEE NOTE 7 BIORETENTION SECTION (NO UNDERDRAIN) STD. PLAN - 262.00 PUBLIC WORKS DEPARTMENT APPROVED: DATEMartin Pastucha Public Works Administrator UNLESS OTHERWISE NOTED, DRAWING IS NOT TO SCALE (NTS) DocuSign Envelope ID: A9707D3B-A0EF-441F-8140-2CDB48E878CA 11/2/2020 | 1:04 PM PST