Loading...
20050755 Storm Drainage Rpt 03202012~ ~L~JW~ ENGINEERING, INCORPORATED _~i~r«! ~rrelr~ireirt ~rc~.s•riona/ Je~uicer Storm Drainage Maintenance Manual Windshadow 14920 Berry Valley Drive SE Yelm, Washington Parcel Nos. 217242-0000, 2172424-0200, & 2172424-0300 Prepared For American West Bank 4 Nickerson Street Suite 200 Seattle. Washington 98109 March 20, 2012 BASELINE Job No. 08-104 Prepared by Jerry A. Waldron. P.E. I ~. ~I'~ `, 3~ ~ a~ ~, . ~~,,,-,h = - ~ Manual content used with permission from the Clty of Port Orchard "Drainage Maintenance Standards for Commeraal and Multi-Family Drainage Facilities,'" dated August 2001 '..' /, r .... ~ ~ Lantl Planning & Use Engineering Surveying 1970-64th Avenuo West•Tacoma. WA 96466 (253)565-4491 Fax (2531566-8563 Seatlle (206)6~J1-1120.5-------------- _ "The industry starts here" Table of Contents Llst of Figures 3 Project Description 3 Drainage Facility Self-Inspection 4 Resource Listing i3 Facility Key g Site Map 10 Maintenance Components 11 Appendix A - InspectionlMaintenance Checklist ' PROJECT DESCRIPTION The project proposal is to subdivide Parcels 217242-0000, 2172424-0200, 8 2172424-0300 ' into 217 residential units composed of single-family residences and townhomes. The project site is composed of Soil Type A -Gravelly Sandy loam and the storm design will utilize underground Low Impact Design BMPs to discharge all runoff generated from the development into the native permeable soils. There is a residential single-family home on-site, which will ' serve as a construction office and will be removed from the site prior to recording of the plat. A public street connected to Tahoma Boulevard to Berry Valley Road. The site is zoned Low Density Residential R-4. ' The 30.2-acre site is located at 14848 SE Berry Valley Rd in Yelm, WA. The subject property is located in the NW quarter of Section 24, Township 17 North, Range 1 East, and W.M. The project will propose a sewer S.T_E.P. system, watermain, storm drainage, and extend dry utilities from Tahoma Boulevard. The project improvements consist of subdividing the parcels into 175 tots for single-family residences, a 10 open space/storm tract areas, 56-foot right of way dedication for the public road improvements and access to the residences, and 20' wide alley way. All interior streets shall be improved to Yelm City Standards for a Local Access Residential, including a 35-foot paved roadway with two 7-foot parking lanes, rolled curb and gutter, and a 5-foot concrete sidewalk on one side. II 1 1 DRAINAGE FACILITY SELF-INSPECTION 1. How the Process Works: Commercial and multifamily property owners within the City of University Place are responsible for inspecting their drainage facilities as well as performing regular maintenance in accordance with City of University Place and Washington Stale Department of Ecology standards. This work may be done either by in-house stall or avendor/contractor. This manual includes an individual site plan showing your property's drainage facilities, information about the jurisdiction's standards for drainage facilities, maintenance information and instructions, and an inspection/maintenance checklist form to be completed indicating that the inspection and maintenance have been completed. A copy of this manual and copies of all completed inspectionlmaintenance checklists must be kept on site at all times. The City may require that you submit the inspectionlmaintenance checklist. Contact the City for submittal requirements. See the Resource Listings on page 8 for contact information. Here are the speciTic steps in the process: A. Facility Identification: Review your site plan on page 10 for drainage facilities such as a pond, lank, vault, etc. To assist you in identifying components, refer to the definitions and sketches in this manual. NOTE: Most systems have both retention/detention (R/D) and conveyance system components (typically a conveyance system can contain a combination of bioswale(s), ditch(es), pipe(s), and catch basins). B. Inspection: Inspect all facilitiesicomponents using in-house personnel or a vendor/contractor. Refer to this manual, which describes the City of University Place standards for each component and identifies possible maintenance problems with number and description. Report the inspection results on the enclosed inspectionlmaintenance checklist in the following manner: • If the facility component already meets the standard, write "meets standard" in the space for that component. • If the component has a maintenance problem, list the problem number from this booklet in the space for that component. NOTE_ If there is more than one component, list the component ID number (i.e., CB #3, CB #4, etc.) along with the problem number. You need only list components with problems in this case. Use the back sheet of the form or attach a separate sheet if necessary. ' C. Maintenance Work: If maintenance is required, have the work performed by in-house personnel or a t vendorlcontractor. On the inspection/maintenance checklist, check off that the work has been completed in the "Work Completed" column, and indicate the date completed. D. Certification: Provide the information indicated and sign under the certification section, certifying under penalty of perjury that the inspection has been performed, and either no maintenance needs were identified or the work was completed as indicated on [he checklist. E. Submittal: ' The City may require that you submit the inspectionlmaintenance checklist. Contact the City for submittal requirements. See the Resource Listings on page 8 for contact information. ' 2. Be Safe! Use caution when entering or working around catch basins and manholes, and conform to confined space entry laws. Most inspections can be performed above ground. If confined space entry is required, it is recommended that you contract with a qualified vendor or contractor with confined space entry experience. 1 Property owners are responsible for the safety of all persons, including in-house and vendor/contractor personnel, performing confined space entry on their property under ' Washington Administrative Code (WAC) 296-62-145, with is Part M, Chapter 62, Confined Spaces. This responsibility may involve undergoing an assessment of the property to determine whether a permit is required for confined space entry. Contact the City for permit requirements. 1 1 1 1 1 1 f For information and assistance, contact Washington State Labor 8 Industries Consultation Program at (206) 281-5470. Information can also be found at http:pwww.lni.wa.gov. 3. Tools of the Trade Depending of the type of facility you have, some of the following tools may be of assistance in doing your own inspection: Task Tool Opening Manhole Cover /Z" Allen Wrench Opening Stuck Lids/Grates Crow Bar • Liquid Wrench Measuring Sediment Depths Measuring rod (an 8-foot length of aluminum conduit marked at 1-foot intervals works well for most systems) • Tape or Chalk II Measuring Storage Space/Sediment Depths Lifting Grates/Lids Inspection from above ground Tape Measure (12ft) Manhole Cover Hook Mirror on a long handle Probing for catch basinslmoving heavy Straight-pointed bar ob ects General Flashlight (6 volt lantern or halogen recommended) • Flat Screwdriver • Phillips Screwdriver • Shovel • Trash Can • Vice Grips • 10" Wrench • 15" Wrench 4. Sediment Estimating-the Most Common Task The most common maintenance problem encountered is excessive sediment level in a Type I ' or Type II Catch Basin. Please refer to this manual for information on other maintenance problems. Here is how to check the sediment level in a Type I or Type II Catch Basin: A. Remove the manhole cover/grate. Using a Y. -inch Allen wrench and a catch basin grate hook or crow bar. i Identify the sump depth (water level). Usiny a probe or rod, identify the sump depth. This is done by inserting the rod through the water and sediment until it hits the bottom of the catch basin; water level will be visible for measurement upon removal. NOTE: Under normal conditions, the water level should be even with the outlet pipe. A higher level indicates a blockage m the outlet. (Refer to the booklet for more information) 8. Identity the sediment level. 1) Put the probe or rod in through the water until it touches the top of the sediment. Mark it with relation to a stationary point in the catch basin wllh tape or chalk (Position A). 2) Put the probe or rod in through the water and sediment until it touches the bottom of the catch basin, and mark the probe with relation to the same stationary point as in Item 1 above (Position B). The difference between the two marks is the sediment depth. a 3) The water mark left on the rod is the "sump depth". Measure the ratio of sediment depth to sump depth to determine the allowable amounts. in Type I and Type II catch basins, the sediment must be removed if the sediment level exceeds one-third (1/3) of the sump depth (water level} in order to meet City of University Place and State of Washington standards. RESOURCE LISTING If after consulting this manual you are still unsure whether a problem exists or the steps that need to be taken to correct the problem. please contact the City of University Place at the number below and ask for technical assistance, Jurisdiction: City of Yelm 360.458-8406 Other Project Contacts Developer: Viking Bank 4 Nickerson Street, Suite 200 Seattle, Washington 98109 Engineer: Baseline Engineering Inc 191064`" Avenue West Tacoma, Washington 98466 253-565-4491 FACILITY KEY Use the table below along with the Site Map on the following page to identify the components of your storm drainage system. Then use the information in the Maintenance Components section of this manual to inspect and maintain your storm drainage system, Storm Drainage System Component I Abbreviation A. Type I Catch Basin CB B. Type II Catch Basin TIICB D. Pipe P E. Infiltration Gallery IG E. 4nfittratson Trench (Private 1 Roof) PT / RT F. Sand Filter I SF p NOlONIF~+M MIEA ~O A.UJ vvrva rw romo.o: • •wn nw.•r wrs-o;e: 'wnas~r rms .Y -,,®""°~- __ e.ptwns ewwyera .vl P apu~.;a owe ~ a.c ~ y ~(/`~ ~'t HIM OOZ 3.LIf18 13~H16 No8H3)IJM 4 cvsv-s.s(scc) m• mx;-.xaoox) .m.s.;a..-catocxl ~_~~ Y i~ NVld ALIlII 31180del0.7 HN'd8 `JNIHN ~-n••~` ,~ "~NI ''JNIa33Nl`JN3 ~~0'~1~~`'~/~ -qx'-mnsa U ~nui a_aoi3n3a/a~aMa nsw ~ti ~ ~f~ I ~~ ~ ~~ (. ~ 1... ~- ~ ,~~ ~ ~~ ~~ R _ ao~ .~ : l~ ~~!! i as I e ~ `. . _, ~ i ~ t ~ I _ ~ es r ~,., ~ ; I W~ W __ __ __ _ ~ ' I 1 c I e ~ I '- .'~ . _• . I• ~ 'i - - Y,_ i a.a.a /x u •rs p t B i I I i. f I g •8 t e I ~~ + ~ I 4- - -- a ~ --,:. _ - `e ..- _ r _ _ 6 . ~ - y _ _ _ _ _ ~~ R x s F I LL ~~ ~ ~ R ~ ~ ~~ r, - . - ~ ~~ 9 M _ g~ '~ p@p~~ o r~~r~uurya¢~ya¢55~~yy~k~yq~~FpCyjx~ /aea/rr~,~,~~Y~Y„~~~R ~ ~ _ ~ _ _ - _ ar ~s9rz~we+o9~l~ooa~.ve~'Io~s t~a ~aunnabo~~wt~oor.~ MAINTENANCE COMPONENTS A. Type I Catch Basin Definition: An underground concrete, water receiving, inlet, rectangular in shape (approximately 3' x 2' x 4' deep) with a slotted iron grate on top to inlet water or a solid rectangular cover. Water may also enter/exit through culverts visible in the side walls of the basin. Maintenance Problem and Number: A.1 Trash 8 Debris (including Sediment) Blocking Water from Entering Basin: Trash or debris of more than '/: cubic foot that is covering the catch basin grate or is blocking the inlet grate to basin by more than 20%. Maintenance Necessary to bring to Standard: Remove all trash and debris from the front of the catch basin inlet. If using a vendor or contractor, ensure that the vendor or contractor properly disposes of waste. If not using a vendor or contractor, call the City for disposal information. A.2 Trash 8 Debris (including Sediment): Trash and debris (in the basin) that exceeds one-third the depth form the bottom of the basin to invert of lowest pipe into or out of the basin. This is the most common maintenance requirement. Maintenance Necessary to bring to Standard: Remove all trash and debris from the catch basin. If using a vendor or contractor, ensure that the vendor or contractor properly disposes of waste. If not using a vendor or contractor, call the City for disposal information. A.3 Trash & Debris (including Sediment): Trash and debris rn any rnfet or outlet prpe blocking more than one-third of its height. Maintenance Necessary to bring to Standard: Remove all trash and debris from inlet and outlet pipes. If using a vendor or contractor, ensure that the vendor or contractor properly disposes of waste. If not using a vendor or contractor, call the City for disposal information. A.4 Settlement/Misalignment: Basin settles more than t inch or has rotated more than 2 inches out of aliynmenl. Maintenance Necessary to bring to Standard: Repair or replace basin to design standards. A.5 Structural Damage to Frame andlor Top Slab: Top concrete slab has holes larger than 2 square inches or cracks wider than % inch (intent is to make sure all material is running into the basin through the grate). Maintenance Necessary to bring to Standard: Repair top slab so that it is free of holes and cracks. A.6 Frame Not Sitting Flush on Top Slab: i.e., separation of more than'/. inch of the frame from the top slab. Maintenance Necessary to bring to Standard: Repair top slab so that it is free of holes and cracks. A.7 Cracks in Basin Walls/Bottom: Cracks wider than'/z inch, any evidence of soil particles or water entering the catch basin through cracks, or maintenance person judges that the structure is unsound. tVtaintenance Necessary to bring to Standard: Repair or replace basin fo design standards. A.8 Cracks in Basin Around InIeUOutiet Culverts: Cracks wider than'/z inch at the joint of any inleUoutlet pipe or any evidence of soil particles or water entering the catch basin through cracks. Maintenance Necessary to bring to Standard: Repair or replace basin to design standards. A.9 Fire Hazard: Presence of chemicals such as natural gas, oil and gasoline. Maintenance Necessary to bring to Standard: Remove flammable chemicals so that none are present. Call the City for disposal information. A.10 Pollution: Presence of any chemical pollution, Maintenance Necessary to bring to Standard: Remove contaminants so that none are present. Call the City for disposal information and notify them of the presence of chemical pollution. A. t 1 Catch Basin Cover Not Jn Alace: Cover is missing or only partially in place. Any open catch basin requires maintenance. Maintenance Necessary to bring to Standard: Repair catch basin cover so that it is closed. A.12 Metal Grates -Safety Hazard: Grate with opening wider than 718 inch. Maintenance Necessary to bring to Standard: Repair grate opening so that they meet design standards. A.13 Metal Grates -Damaged or Missing: Grate is missing or has broken members. Maintenance Necessary to bring to Standard: Repair or replace grate so that it Is in place and meets design Standards. 8. Type +i' Catch Sasin Definition: A round underground concrete basin (4'- 8' diameter, 6' deep or deeper), may contain a PROP (Flow Restrirtor/Oil Pollution Control device). These basins are also required when larger diameter Culverts are used. Maintenance Problem and Number: 8.1 Trash & Debris (including Sediment) Blocking Water from Entering Basin: Trash or debris of more than % cubic foot that is covering the catch basin grate or is blocking the inlet grate to basin by more than 20%. h4aintenance Necessary to bring fo Standard: Remoa~e a!! trash and debris from the front of the catch basin inlet. If using a vendor or contractor, ensure that the vendor or contractor properly disposes of waste. If not using a vendor or contractor, call the City for disposal information. 6.2 Trash & Debris (including Sediment): Trash and debris (in the basin) that exceeds one-third the depth form the bottom of the basin to invert of lowest pipe into or out of the basin. This is the most common maintenance requirement. Maintenance Necessary to bring to Standard: Remove all trash and debris from the catch basin. If using a vendor or contractor, ensure that the vendor or contractor property disposes of waste. If not using a vendor or contractor, call the City for disposal information. 6.3 Trash & Debris (including Sediment): Distance between trash and debris build- up from the bottom of orifice plate is less than 1-1l2 feet. Maintenance Necessary to bring to Standard: Remove all trash and debris from the catch basin. If using a vendor or contractor, ensure that the vendor or contractor properly disposes of waste. if not using a vendor or contractor, call the City for disposal information. 6.4 Structural Damage to Frame and/or Top Slabs Top concrete slab has holes larger than 2 square inches or cracks wider than %. inch (intent is to make sure all material is running into the basin through the grate). Maintenance Necessary to bring to Standard: Repair top slab so that it is free of holes and cracks. 6.5 Frame Not Sitting Flush on Top Siab: i.e., separation of more than'h inch of the frame from the top slab. Maintenance Necessary to bring to Standard: Repair top slab so that it is free of holes and cracks. B.6 Cracks in Basin WailslBottom: Cracks wider than 1!2 inch and longer than 3 feet, any evidence of soil particles or water entering the catch basin through cracks, or maintenance person judges that the structure is unsound. Maintenance Necessary to bring to Standard: Repair or replace basin to design standards. 8.7 Cracks in Basin Around Inlet/Outlet Culverts: Cracks wider than Y, inch and longer than 1 foot at the joint of any inleUoutlet pipe or any evidence of soil particles or water entering the catch basin through cracks. Connections to inleUoutlet pipe are not watertight and show signs of rust. Maintenance Necessary to bring to Standard: Repair or replace basin to design standards. Repair connection to pipe to become watertight. 8.8 Settlement/Misalignmenf: Basin settles more than 1 inch or has rotated more than 6 inches out of alignment. Maintenance Necessary to bring to Standard: Repair or replace basin to design standards. 6.9 Fire Hazard: Presence of chemicals such as natural gas, oil and gasoline. Maintenance Necessary to bring to Standard: Remove flammable chemicals so that none are present. Call the City for disposal information. 6.10 Pollution: Presence of any chemical pollution. Maintenance Necessary to bring to Standard: Remove contaminants so that none are present. Call the City for disposal information and notify them of fhe presence of chemical pollution. 6.11 Catch Basin Cover Not In Place: Cover is missing or only partially in place. Any open catch basin requires maintenance. fvtaintenance Necessary to bring to Standard: Repair catch basin cover so that it is closed. 8.12 Metal Grates -Safety Hazard: Grate with opening wider than 718 inch. Maintenance Necessary to bring to Standard: Repair grate opening so that they meet design standards. 6.13 Metal Grates -Damaged or Missing: Grate is missing or has broken members. Maintenance Necessary to bring to Standard' Repair or replace grate so that it is in place and meets design standards. 6.14 Metal Grates -Trash and Debris: Trash or debris that is blocking more than 20% of the grate surface. 1 Maintenance Necessary to bring to Standard: Remove all trash and debris from grate. B.15 Access ladder -Unsafe: Ladder is unsafe due to missing rungs, misalignment, rust or cracks. Maintenance Necessary to bring to Standard: Repair ladder so that It is in place and meets design standards and allows maintenance person safe access. D. Pipe /Culvert Definition: A conveyance culvert of varying diameter. May be constructed as concrete pipe (CP), reinforced concrete pipe (RCP), corrugated metal pipe (CMP), high density (smooth wall) polyethylene pipe (HDPP), ductile iron (DI), or corrugated high density polyethylene pipe (CPEP), or polyvinyl chloride pipe (PVC). Maintenance Problem and Number: D.1 Sediment & Debris: Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Maintenance Necessary to bring to Standard: Clean pipe of all sediment and debris. D.2 Vegetation: Vegetation that reduces free movement of water through pipes. Maintenance Necessary to bring to Standard: Remove vegetation so water flows freely through pipes. D.3 Protective Coating Damage: Protective coating is visibly damaged, or rust is causing more than 50% deterioration to any part of the pipe. Maintenance Necessary to bring to Standard: Repair or replace pipe. D.4 Joint or Culvert Misalignment: Joints are visibly misaligned, or culverts alignment is disrupted. Maintenance Necessary to bring to Standard: Realign or re-connect affected pipe. D.5 Pipe Damaged: Any dents that decrease the cross sectional area of the pipe by more than 20%. Maintenance Necessary to bring to Standard: Repair or replace pipe. E. & F. Other -Specific to Infiltration & Sand Fitter Definition: A stormwater facility designed to store runoff while allowing it to penetrate into the native soil. Due to the high permeable soils imported sand is required below the trench of the sand filter to reduce the infiltration rates from 20 inches/hr (3 min/in) to 2 inches/hr (30 min/in). Maintenance Problem and Number: E.1 Plugged Air Vents: qne-half of the end area of the vent is blocked at any point with sediment and/or debris. Maintenance Necessary to bring to Standard: Remove sediment and debris so that there is no clogging or blockage in the vent. If using a vendor or contractor, ensure that the vendor or contractor property disposes of waste. If not using a vendor or contractor, tail the City for disposal information. E.2 Storage Area -Sediment (Infiltration Tanks and Vaults Only): Accumulated sediment that exceeds 6 inches in depth. Maintenance Necessary to bring to Standard: Remove all sediment from the storage area in the vault. If using a vendor or contractor, ensure that the vendor or contractor property disposes of waste. If not using a vendor or contractor, call the City (or disposal information. E.3 Gaps between VaulUPipe Section (Infiltration Tanks Only): Any cracks allowing material to enter into the facility. Maintenance Necessary to bring to Standard: Seal all joints between tank/pipe sections. E.4 Tank/Pipe -Structural Damage (Infiltration Tanks Only): Any part of the tank/pipe that is bent out of shape more than 10% of its design shape. Maintenance Necessary to bring to Standard: Repair or replace tank/pipe to design standards. NOTES: 1. Sediment accumulations of more than 0.25 inches per year may indicate excessive erosion is occurring upstream of the facility or that the conveyance systems are nol being properly maintained. The contributing drainage area should be checked for erosion problems or inadequate maintenance of conveyance systems if excessive sedimentation is noted in an infiltration facility. 2. In order to access the effectiveness of the infiltration function, inspection is recommended of downspouts, drains and catch basins during a storm. Also, evaluate adjacent properties for damages causetl by system failure. Slow water dissipation or system backups and flooding may indicate that an infiltration system is not adequately peKorming. APPENDIX A INSPECTION/MAINTENANCE CHECKLIST DRAINAGE FACILITY INSPECTION/MAINTENANCE CHECKLIST (Checklist content used xnth permission fran the City of Port Orchard "Pnvate Drainage FacAity 2003 Maintenance Checklist) Property Name:_ Property Address:_ Property Owner or I -Checklist Instructions for properly owner/manager or maintenance vendorlcontractor. 1. Refer to your site plan and component definitions in the Storm Drainage Maintenance Manual to determine which facilities you have on your property. (On the site plan, "CB" refers to catch basin, "CI" to curb inlet, "MH" to manhole, and "CMH" to control manhole.) 2. Within the appropriate facility type section check "yes" or "no" indicating whether you have each facility component on your property (i.e. Type II catch basin, pipe, etc.). 3. Inspect each component for maintenance problems (refer to Storm Drainage Maintenance Manual.) 4. In the "Meets Standard or Problems" column, list the applicable defect number (A.I, A.2, etc.) from the Storm Drainage Maintenance Manual or write "Meets Standard" if the component meets the standard at the time of the inspection. (NOTE: If there is more than one component for a facility type, list each component by its number on the site plan (CB-1, CS-2, etc.) along with the problem number. You need only list the components with problems in this case.) Use the back page of the form or add a separate sheet if necessary. 5. Perform maintenance on all facilities that have problems in order to bring them to the appropriate standard (refer to the Storm Drainage Maintenance Manual). 6. Check off work that has been completed and write in the date the work completed. l Facility Type Component (See standards booklet) Yes/NO 'Meets Standard" Work Completed Or Problem Number ~ Date WaterQual' -Continued Public: 1. Infltration (not Including ponds) E. Infiltration Gallery Definition: Undergrountl or erforated e tank pip , p , vault system that allows private: runoff to percolate back E. Roof Infiltration Trench (Provide Lol Number) info surrounding so+7. Some may have assoaated Type I Catch Basins. Type II Catch B i M h l as ns ( an o es), or elements to facilRate inspection and cleaning. Public: 2. Conveyance A. Type I Catch Basin (Inlet) L'ef~mhon.- Culverts, pipes, B, Type II Catch Basin dittoes, vetch basins, and manholes that pick up and convey runofl from Dpi e p buildings and parking ereas to one of the above RiD facilities. Private: A. Type I Catch Basin (Inlet) B. Type II Catch Basin (Control Manhole) D Pipe Water Quali F Sand Filler 3. Filtration System Definition: A system whero import sand slows down the infiurafion :ate (See Appendix C for manufacturer's Operation and Maintenance Guidelines for maintenance requirements and manufacturer's checklists) 2 ' II- Certification I, the undersigned, do hereby certify under penalty of perjury, that the inspection has been performed, the materials have been furnished, the services rendered, and/or the labor performed as deemed necessary from the inspection to meet City of University Place standards and as indicated above. Signature (Owner/Managing Agent) Printed Name Service Contractor Name Representative's Signature PLEASE NOTE ANY CHANGES IN OWNERSHIP/MANAGING AGENT OR COMMENTS IN THE SPACE PROVIDED BELOW' 3