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HomeMy WebLinkAboutMaintenance and Operation Manual - BLD Engineering / Geo-tech Reports - 12/21/2017 fHFtE NAWS MUST BE C N THE JOB SITE 'XJR NSPECTION Maintenance and Operation Manual for Shearer Single Family Residential Property 401 NE Timberline Drive Parcel No. 12320-34-00030 Mason County, Washington December 21, 2017 Project#17195 TO BE KEPT IN THE RECEIVED PARCEL FILE JAN 0 8 2018 Prepared For: 615 W. Alder .`.street Tom Shearer PO Box 1959 Belfair, Washington 98528 cLYDE S w Sys T Q Prepared By: Envirotech Engineering, PLLC PO Box 984 3 5 4� Belfair, Washington 98528 °��R�C/STER�°G`�� Phone: 360-275-9374 S/ONALE� Introduction Envirotech Engineering, PLLC (Envirotech) has completed this maintenance manual for a proposed single family residential development located at 401 NE Timberline Drive (Parcel 12320-34-00030) in Belfair, Mason County, Washington. Manual Purpose The purpose of this manual is to provide the property owner with a specific maintenance plan in order to ensure the continued proper operation of all stormwater management facilities associated with this project. Lack of maintenance could lead to local flooding, water damage, excess pollution, and/ or costly repairs or replacements of property or drainage systems. Maintenance Responsibilities Facility maintenance is ultimately the responsibility of the current property owner. Currently, stormwater maintenance responsibility for this property belongs to: Tom Shearer PO Box 1959 Belfair, Washington 98528 Maintenance Requirements The stormwater management facilities provided in Attachment A include provisions for inspection procedures and maintenance, when necessary. All stormwater facilities that were designed for are accounted for. Maintenance procedures for additional components are also provided, which consist of general practices for some of the selected drainage features for this development. Only applicable facilities and components per the stormwater design are required to be inspected and maintained. Envirotech Engineering Operation and Maintenance Manual Ph. 360-275-9374 Page I of 1 401 NE Timberline Drive, Belfair Fax: 360-275-4789 Parcel 12320-34-00030 December 21,2017 ATTACHMENT A 4.6 Maintenance Standards for Drainage Facilities The facility-specific maintenance standards contained in this section are intended to be conditions for determining if maintenance actions are required as identified through inspection. They are not intended to be measures of the facility's required condition at all times between inspections. In other words, exceedence of these conditions at any time between inspections and/or maintenance does not automatically constitute a violation of these standards. However, based upon inspection observations, the inspection and maintenance schedules shall be adjusted to minimize the length of time that a facility is in a condition that requires a maintenance action. Table 4.5—Maintenance Standards No. 1 —Detention Ponds Maintenance Defect Conditions When Maintenance Is Results Expected When Component Needed Maintenance Is Performed General Trash&Debris Any trash and debris which exceed 5 Trash and debris cleared from site. cubic feet per 1,000 square feet(this is about equal to the amount of trash it would take to fill up one standard size garbage can). In general,there should be no visual evidence of dumping. If less than threshold all trash and debris will be removed as part of next scheduled maintenance. Poisonous Any poisonous or nuisance No danger of poisonous vegetation Vegetation and vegetation which may constitute a where maintenance personnel or the noxious weeds hazard to maintenance personnel or public might normally be. (Coordinate the public. with local health department) Any evidence of noxious weeds as Complete eradication of noxious weeds defined by State or local regulations. may not be possible. Compliance with State or local eradication policies (Apply requirements of adopted IPM required policies for the use of herbicides). Contaminants Any evidence of oil,gasoline, NO and Pollution contaminants or other pollutants its OF POIltAdWS (Coordinate removal/cleanup with V _ local water quality response agency). Rodent Holes Any evidence of rodent holes if Rodents destroyed and dam or berm facility is acting as a dam or berm,or repaired. (Coordinate with local health any evidence of water piping through department; coordinate with Ecology dam or berm via rodent holes. Dam Safety Office if pond exceeds 10 acre-feet.) 4-30 Volume V—Runoff Treatment BMPs February 2005 No. 1 —Detention Ponds Maintenance Defect Conditions When Maintenance Is Results Expected When Component Needed Maintenance Is Performed Beaver Dams Dam results in change or function of Facility is returned to design function. the facility. (Coordinate trapping of beavers and removal of dams with appropriate permitting agencies) Insects When insects such as wasps and Insects destroyed or removed from site. hornets interfere with maintenance activities. Apply insecticides in compliance with adopted IPM policies Tree Growth Tree growth does not allow Trees do not hinder maintenance and Hazard maintenance access or interferes activities. Harvested trees should be Trees with maintenance activity(i.e.,slope recycled into mulch or other beneficial mowing,silt removal,vactoring,or uses(e.g.,alders for firewood). equipment movements). If trees are not interfering with access or Remove hazard Trees maintenance,do not remove If dead,diseased,or dying trees are identified (Use a certified Arborist to determine health of tree or removal requirements) Side Slopes Erosion Eroded damage over 2 inches deep Slopes should be stabilized using of Pond where cause of damage is still appropriate erosion control measure(s); present or where there is potential for e.g., rock reinforcement, planting of continued erosion. grass,compaction. Any erosion observed on a If erosion is occurring on compacted compacted berm embankment. berms a licensed civil engineer should be consulted to resolve source of erosion. Storage Area Sediment Accumulated sediment that exceeds Sediment cleaned out to designed pond 10%of the designed pond depth shape and depth; pond reseeded if unless otherwise specified or affects necessary to control erosion. inletting or outletting condition of the facility. Liner(If Liner is visible and has more than Liner repaired or replaced. Liner is fully Applicable) three 1/4-inch holes in it. covered. February 2005 Volume V—Runoff Treatment BMPs 4-31 No. 1 —Detention Ponds Maintenance Defect Conditions When Maintenance Is Results Expected When Component Needed Maintenance Is Performed Pond Berms Settlements Any part of berm which has settled 4 Dike is built back to the design (Dikes) inches lower than the design elevation. elevation. If settlement is apparent, measure berm to determine amount of settlement. Settling can be an indication of more severe problems with the berm or outlet works. A licensed civil engineer should be consulted to determine the source of the settlement. Piping Discernable water flow through pond Piping eliminated. Erosion potential berm. Ongoing erosion with potential resolved. for erosion to continue. (Recommend a Goethechnical engineer be called in to inspect and evaluate condition and recommend repair of condition. Emergency Tree Growth Tree growth on emergency spillways Trees should be removed. If root Overflow/ creates blockage problems and may system is small (base less than 4 Spillway and cause failure of the berm due to inches)the root system may be left in Berms over 4 uncontrolled overtopping. place. Otherwise the roots should be feet in height. removed and the berm restored. A Tree growth on berms over 4 feet in licensed civil engineer should be height may lead to piping through the consulted for proper berm/spillway berm which could lead to failure of restoration. the berm. Piping Discernable water flow through pond Piping eliminated. Erosion potential berm. Ongoing erosion with potential resolved. for erosion to continue. (Recommend a Goethechnical engineer be called in to inspect and evaluate condition and recommend repair of condition. Emergency Emergency Only one layer of rock exists above Rocks and pad depth are restored to Overflow/ Overflow/ native soil in area five square feet or design standards. Spillway Spillway larger,or any exposure of native soil at the top of out flow path of spillway. (Rip-rap on inside slopes need not be replaced.) Erosion See"Side Slopes of Pond" 4-32 Volume V—Runoff Treatment BMPs February 2005 No. 2—Infiltration Maintenance Defect Conditions When Maintenance Is Results Expected When Component Needed Maintenance Is Performed General Trash&Debris See"Detention Ponds"(No. 1). See"Detention Ponds" (No. 1). Poisonous/Noxious See"Detention Ponds"(No. 1). See"Detention Ponds" Vegetation (No. 1). Contaminants and See"Detention Ponds"(No. 1). See"Detention Ponds" Pollution (No. 1). Rodent Holes See"Detention Ponds"(No. 1). See"Detention Ponds" (No. 1) Storage Area Sediment Water ponding in infiltration pond after Sediment is removed rainfall ceases and appropriate time and/or facility is cleaned allowed for infiltration. so that infiltration system works according to (A percolation test pit or test of facility design. indicates facility is only working at 90%of its designed capabilities. If two inches or more sediment is present, remove). Filter Bags(if Filled with Sediment and debris fill bag more than 1/2 Filter bag is replaced or applicable) Sediment and full. system is redesigned. Debris Rock Filters Sediment and By visual inspection, little or no water flows Gravel in rock filter is Debris through filter during heavy rain storms. replaced. Side Slopes of Erosion See"Detention Ponds"(No. 1). See"Detention Ponds" Pond (No. 1). Emergency Tree Growth See"Detention Ponds"(No. 1). See"Detention Ponds" Overflow Spillway (No. 1). and Berms over 4 feet in height. Piping See"Detention Ponds"(No. 1). See"Detention Ponds" (No. 1). Emergency Rock Missing See"Detention Ponds"(No. 1). See"Detention Ponds" Overflow Spillway (No. 1). Erosion See"Detention Ponds"(No. 1). See"Detention Ponds" (No. 1). Pre-settling Facility or sump 6"or designed sediment trap depth of Sediment is removed. Ponds and Vaults filled with Sediment sediment. and/or debris February 2005 Volume V—Runoff Treatment BMPs 4-33 No. 5—Catch Basins Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed General Trash& Trash or debris which is located immediately No Trash or debris located Debris in front of the catch basin opening or is immediately in front of blocking inletting capacity of the basin by catch basin or on grate more than 10%. opening. Trash or debris(in the basin)that exceeds 60 No trash or debris in the percent of the sump depth as measured from catch basin. the bottom of basin to invert of the lowest pipe into or out of the basin, but in no case less than a minimum of six inches clearance from the debris surface to the invert of the lowest pipe. Trash or debris in any inlet or outlet pipe Inlet and outlet pipes free blocking more than 1/3 of its height. of trash or debris. Dead animals or vegetation that could No dead animals or generate odors that could cause complaints vegetation present within or dangerous gases(e.g., methane). the catch basin. Sediment Sediment(in the basin)that exceeds 60 No sediment in the catch percent of the sump depth as measured from basin the bottom of basin to invert of the lowest pipe into or out of the basin, but in no case less than a minimum of 6 inches clearance from the sediment surface to the invert of the lowest pipe. Structure Top slab has holes larger than 2 square Top slab is free of holes Damage to inches or cracks wider than 1/4 inch and cracks. Frame and/or Top Slab (Intent is to make sure no material is running into basin). Frame not sitting flush on top slab, i.e., Frame is sitting flush on separation of more than 3/4 inch of the frame the riser rings or top slab from the top slab. Frame not securely and firmly attached. attached Fractures or Maintenance person judges that structure is Basin replaced or repaired Cracks in unsound. to design standards. Basin Walls/ Bottom Grout fillet has separated or cracked wider Pipe is regrouted and than 1/2 inch and longer than 1 foot at the secure at basin wall. joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. Settlement/ If failure of basin has created a safety, Basin replaced or repaired Misalignment function,or design problem. to design standards. Vegetation Vegetation growing across and blocking more No vegetation blocking than 10%of the basin opening. opening to basin. Vegetation growing in inlet/outlet pipe joints No vegetation or root that is more than six inches tall and less than growth present. six inches apart. 4-36 Volume V—Runoff Treatment BMPs February 2005 No. 5—Catch Basins Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed Contamination See"Detention Ponds"(No. 1). No pollution present. and Pollution Catch Basin Cover Not in Cover is missing or only partially in place. Catch basin cover is Cover Place Any open catch basin requires maintenance. closed Locking Mechanism cannot be opened by one Mechanism opens with Mechanism maintenance person with proper tools. Bolts proper tools. Not Working into frame have less than 1/2 inch of thread. Cover Difficult One maintenance person cannot remove lid Cover can be removed by to Remove after applying normal lifting pressure. one maintenance person. (Intent is keep cover from sealing off access to maintenance.) Ladder Ladder Rungs Ladder is unsafe due to missing rungs, not Ladder meets design Unsafe securely attached to basin wall, standards and allows misalignment, rust,cracks,or sharp edges. maintenance person safe access. Metal Grates Grate opening Grate with opening wider than 7/8 inch. Grate opening meets (If Applicable) Unsafe design standards. Trash and Trash and debris that is blocking more than Grate free of trash and Debris 20%of grate surface inletting capacity. debris. Damaged or Grate missing or broken member(s)of the Grate is in place and Missing. grate. meets design standards. No. 6—Debris Barriers(e.g.,Trash Racks) Maintenance Defect Condition When Maintenance is Results Expected When Components Needed Maintenance is Performed General Trash and Trash or debris that is plugging more Barrier cleared to design flow Debris than 20%of the openings in the barrier. capacity. Metal Damaged/ Bars are bent out of shape more than 3 Bars in place with no bends more Missing inches. than 3/4 inch. Bars. Bars are missing or entire barrier Bars in place according to design. missing. Bars are loose and rust is causing 50% Barrier replaced or repaired to deterioration to any part of barrier. design standards. [Inlet/Outlet Debris barrier missing or not attached to Barrier firmly attached to pipe Pe pipe February 2005 Volume V—Runoff Treatment BMPs 4-37 I No. 10—Filter Strips Maintenance Defect or Condition When Recommended Maintenance to Correct Component Problem Maintenance is Needed Problem General Sediment Sediment depth exceeds 2 Remove sediment deposits, re-level so Accumulation on inches. slope is even and flows pass evenly through Grass strip. Vegetation When the grass becomes Mow grass,control nuisance vegetation, excessively tall(greater such that flow not impeded. Grass should be than 10-inches);when mowed to a height between 3-4 inches. nuisance weeds and other vegetation starts to take over. Trash and Debris Trash and debris Remove trash and Debris from filter. Accumulation accumulated on the filter strip. Erosion/Scouring Eroded or scoured areas For ruts or bare areas less than 12 inches due to flow channelization, wide, repair the damaged area by filling with or higher flows. crushed gravel. The grass will creep in over the rock in time. If bare areas are large, generally greater than 12 inches wide,the filter strip should be re-graded and re- seeded. For smaller bare areas,overseed when bare spots are evident. Flow spreader Flow spreader uneven or Level the spreader and clean so that flows clogged so that flows are are spread evenly over entire filter width. not uniformly distributed through entire filter width. February 2005 Volume V-Runoff Treatment BMPs 4-41