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HomeMy WebLinkAboutRC 20230202000071 Return Address: I City Clerk's Office 1 1111 Y Cit of Renton 11111111 I��� I�III III�I�II�II�II�I!!II� IIIllllll�II 1055 S Grady Way 20230202000071 Renton,WA 98057 COVENANT Roc:$244.60 2/2/2023 9:05 AM KING COUNTY,WA DECLARATION OF COVENANT FOR INSPECTION AND MAINTENANCE OF DRAINAGE FACILITIES AND ON-SITE BMPS Grantor: MainVue WA LLC Pt I ELAt Pc!2-E L)NM-CD CAAYIPA-N-14 Grantee: City of Renton,a Washington municipal corporation Legal Description: PTN SEC 14 TWP 23N RGE 5E SW QTR SE QTR, KING COUNTY See Exhibit C for full legal description Assessor's Tax Parcel ID#: 142305-9013 IN CONSIDERATION of the approved City of Renton (check one of the following) ['Residential Building Permit ['Commercial Building Permit ❑Clearing and Grading Permit ©Civil Construction or Utility Permit for Permit(s)C21003180 (Construction/Building/Utility Permit#)relating to the real property ("Property") described above, the Grantor(s), the owner(s) in fee of that Property, hereby covenants (covenant)with the City of Renton ("City of Renton" or"City"),a municipal corporation of the state of Washington,that he/she(they)will observe,consent to,and abide by the conditions and obligations set forth and described in Paragraphs 1 through 9 below with regard to the Property, and hereby grants (grant) an easement as described in Paragraphs 2 and 3. Grantor(s) hereby grants (grant),covenants(covenant),and agrees (agree)as follows: 1. The Grantor(s)or his/her(their)successors in interest and assigns("Owners")shall at their own cost,operate, maintain, and keep in good repair,the Property's drainage facilities constructed as required in the approved construction plans and specifications TED-40-4188 (Project Plan#) on file with the City of Renton and submitted to the City of Renton for the review and approval of permit(s) C21003180 (Construction/Building/Utility Permit#).The Property's drainage facilities are shown and/or listed on Exhibit A—Site Plan. The Property's drainage facilities shall be maintained in compliance with the operation and maintenance schedule included and attached herein as Exhibit B—Operations and Maintenance. Drainage facilities include pipes, channels, flow control facilities, water quality facilities, on-site best management practices (BMPs) and other engineered structures designed to manage and/or Page 1 of 42 s .4, 7 l treat stormwater on the Property. On-site BMPs include dispersion and infiltration devices, bioretention, permeable pavements, rainwater harvesting systems, tree retention credit, reduced impervious surface footprint,vegetated roofs and other measures designed to mimic pre-developed hydrology and minimize stormwater runoff on the Property. 2. City of Renton shall have the right to ingress and egress over those portions of the Property necessary to perform inspections of the stormwater facilities and BMPs and conduct maintenance activities specified in this Declaration of Covenant and in accordance with the Renton Municipal Code. City of Renton shall provide at least thirty(30) days'written notice to the Owners that entry on the Property is planned for the inspection of drainage facilities.After the thirty(30) days,the Owners shall allow the City of Renton to enter for the sole purpose of inspecting drainage facilities. In lieu of inspection by the City,the Owners may elect to engage a licensed civil engineer registered in the state of Washington who has expertise in drainage to inspect the drainage facilities and provide a written report describing their condition. If the engineer option is chosen,the Owners shall provide written notice to the City of Renton within fifteen(15)days of receiving the City's notice of inspection.Within thirty(30)days of giving this notice,the Owners,or engineer on behalf of the Owners,shall provide the engineer's report to the City of Renton. If the report is not provided in a timely manner as specified above,the City of Renton may inspect the drainage facilities without further notice. 3. If City of Renton determines from its inspection, or from an engineer's report provided in accordance with Paragraph 2,that maintenance, repair, restoration,and/or mitigation work is required to be done to any of the drainage facilities, City of Renton shall notify the Owners of the specific maintenance, repair, restoration, and/or mitigation work ("Work") required pursuant to the Renton Municipal Code. The City shall also set a reasonable deadline for the Owners to complete the Work, or to provide an engineer's report that verifies completion of the Work. After the deadline has passed, the Owners shall allow the City access to re-inspect the drainage facilities unless an engineer's report has been provided verifying completion of the Work. If the Work is not completed within the time frame set by the City, the City may initiate an enforcement action and/or perform the Work and hereby is given access to the Property for such purposes. Written notice will be sent to the Owners stating the City's intention to perform such Work.This Work will not commence until at least seven(7)days after such notice is mailed. If, within the sole discretion of the City, there exists an imminent or present danger, the seven (7) day notice period will be waived and Work will begin immediately. 4. The Owners shall assume all responsibility for the cost of any Work,or any measures taken by the City to address conditions as described in Paragraph 3. Such responsibility shall include reimbursement to the City within thirty(30)days of the receipt of the invoice for any such Work performed. Overdue payments will require payment of interest at the maximum legal rate allowed by RCW 19.52.020(currently twelve percent(12%)). If the City initiates legal action to enforce this agreement, the prevailing party in such action is entitled to recover reasonable litigation costs and attorney's fees. 5. The Owners are required to obtain written approval from City of Renton prior to filling, piping, cutting, or removing vegetation (except in routine landscape maintenance) in open vegetated stormwater facilities (such as swales, channels, ditches, ponds, etc.), or performing any alterations or modifications to the drainage facilities referenced in this Declaration of Covenant. Page 2 of 42 6. Any notice or consent required to be given or otherwise provided for by the provisions of this Agreement shall be effective upon personal delivery,or three(3)days after mailing by Certified Mail, return receipt requested. 7. With regard to the matters addressed herein,this agreement constitutes the entire agreement between the parties, and supersedes all prior discussions, negotiations, and all agreements whatsoever whether oral or written. 8. This Declaration of Covenant is intended to protect the value and desirability and promote efficient and effective management of surface water drainage of the real property described above, and shall inure to the benefit of all the citizens of the City of Renton and its successors and assigns. This Declaration of Covenant shall run with the land and be binding upon Grantor(s),and Grantor's(s')successors in interest,and assigns. 9. This Declaration of Covenant may be terminated by execution of a written agreement by the Owners and the City that is recorded by King County in its real property records. IN WITNESS WHEREOF, this Declaration of Covenant for the Inspection and Maintenance of Drainage Facilities is executed this 2S day of V 3O bed ,20 22-. MainVue WA LLC GRANTOR,owner of the Property Vanessa Normandin President of MainVue Homes LLC, Manager of MainVue WA LLC STATE OF WASHINGTON COUNTY OF KING )ss. On this day personally appeared before me: \kAV\.QSSO\ 1\-10\rmcLncli.,/-\__ , to me known to be the individual(s) described in and who executed the within and foregoing instrument and acknowledged that they signed the same as their free and voluntary act and deed,for the uses and purposes therein stated. Given under my hand and official seal this 2ta day of 1\-30\i'eAY‘ -r , 202.2. 2. AtIA DV. pith +oja'� ' -.0 Printed name 0 %°22031220 % Notary Public in and for the State of i IPA AtiltP = 2: Washington, residing at lilt +t«W�s• My appointment expires (p_ l0-2026 Page 3 of 42 1 1 EXHIBIT A - SITE PLAN Page 4 of 42 N o II I I El O 04 O LLI J IR U WW' - -1-- -_L- --L -- -L- - T_L - �p--I/ (� Q CONNECT TO EXISTING I O STORM SYSTEM o p CONTECH CDS I r • 'I _—•�ii CITY OF RENTON R-4 ?lam i TRACT B �� \: CONTECH 7 STORM FILTER �li PUBLIC TRACT ; ; I I I I T 1 STORM LINE lg 1 ) I ACO ST IRMBRIXX j j 3 4 s ' ' 6a Lv riti _INFILTRATION FACILITY I J L �__ t ! 8 CF 74:r CITY QF RENTON IR-4 C,,, 4 KING COUNTY R-4 'aA°"M f �' T 11j � I�..t A. 11 I I —-I < ;.I I 14 1 SE 143RD ST 11 IIII / Page 5 of 42 3 1 EXHIBIT B - OPERATIONS AND MAINTENANCE 1. Appendix A "Maintenance Requirements for Stormwater Facilities and On-site BMPs" from the 2017 City of Renton Surface Water Design Manual 2. Contech Engineered Solutions StormFilter Inspection and Maintenance Procedures Guide, dated August 2016 3. ACO StormBrixx Maintenance and Inspection Guidance 4. Contech Engineered Solutions CDS Guide - Operation, Design, Performance and Maintenance, dated March 2017 Page 6 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.3-DETENTION TANKS AND VAULTS MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic Trash and debris cleared from site. foot per 1,000 square feet(this is about equal to the amount of trash it would take to fill up one standard size office garbage can).In general,there should be no visual evidence of dumping. Noxious weeds Any noxious or nuisance vegetation which Noxious and nuisance vegetation removed may constitute a hazard to City personnel according to applicable regulations.No or the public. danger of noxious vegetation where City personnel or the public might normally be. Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of pollution such as oil,gasoline,concrete slurries or according to applicable regulations.Source paint. control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of Grass or groundcover exceeds 18 inches Grass or groundcover mowed to a height grass/groundcover in height. no greater than 6 inches. Tank or Vault Trash and debris Any trash and debris accumulated in vault No trash or debris in vault. Storage Area or tank(includes floatables and non- floatables). Sediment Accumulated sediment depth exceeds All sediment removed from storage area. accumulation 10%of the diameter of the storage area for 1/2 length of storage vault or any point depth exceeds 15%of diameter.Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than length of tank. Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of Any part of tank/pipe is bent out of shape Tank repaired or replaced to design. shape more than 10%of its design shape. Gaps between A gap wider than%-inch at the joint of any No water or soil entering tank through sections,damaged tank sections or any evidence of soil joints or walls. joints or cracks or particles entering the tank at a joint or tears in wall through a wall. Vault Structure Damage to wall, Cracks wider than%-inch,any evidence of Vault is sealed and structurally sound. frame,bottom,and/or soil entering the structure through cracks top slab or qualified inspection personnel determines that the vault is not structurally sound. Inlet/Outlet Pipes Sediment Sediment filling 20%or more of the pipe. Inlet/outlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in No trash or debris in pipes. inlet/outlet pipes(includes floatables and non-floatables). Damaged inlet/outlet Cracks wider than%-inch at the joint of the No cracks more than%-inch wide at the pipes inlet/outlet pipes or any evidence of soil joint of the inlet/outlet pipe. entering at the joints of the inlet/outlet pipes. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in Manhole access covered. place.Any open manhole requires immediate maintenance. Page 7 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.3-DETENTION TANKS AND VAULTS MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Access Manhole Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. (cont.) not working maintenance person with proper tools. Bolts cannot be seated.Self-locking cover/lid does not work. Cover/lid difficult to One maintenance person cannot remove Cover/lid can be removed and reinstalled remove cover/lid after applying 80 lbs of lift. by one maintenance person. Ladder rungs unsafe Missing rungs,misalignment,rust,or Ladder meets design standards.Allows cracks. maintenance person safe access. Large access Damaged or difficult Large access doors or plates cannot be Replace or repair access door so it can doors/plate to open opened/removed using normal equipment. opened as designed. Gaps,doesn't cover Large access doors not flat and/or access Doors close flat;covers access opening completely opening not completely covered. completely. Lifting rings missing, Lifting rings not capable of lifting weight of Lifting rings sufficient to lift or remove door rusted door or plate. or plate. • Page 8 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.4-CONTROL STRUCTURE/FLOW RESTRICTOR MAINTENANCE DEFECT OR CONDITION WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPONENT PROBLEM IS NEEDED MAINTENANCE IS PERFORMED • Structure Trash and debris Trash or debris of more than cubic foot No Trash or debris blocking or potentially which is located immediately in front of the blocking entrance to structure. structure opening or is blocking capacity of the structure by more than 10%. Trash or debris in the structure that No trash or debris in the structure. exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. Deposits of garbage exceeding 1 cubic No condition present which would attract or foot in volume. support the breeding of insects or rodents. Sediment Sediment exceeds 60%of the depth from Sump of structure contains no sediment. accumulation the bottom of the structure to the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section or is within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Damage to frame Corner of frame extends more than%inch Frame is even with curb. and/or top slab past curb face into the street(If applicable). Top slab has holes larger than 2 square •Top slab is free of holes and cracks. inches or cracks wider than%inch. Frame not sitting flush on top slab,i.e., Frame is sitting flush on top slab. separation of more than' inch of the frame from the top slab. Cracks in walls or Cracks wider than%inch and longer than Structure is sealed and structurally sound. bottom 3 feet,any evidence of soil particles entering structure through cracks,or maintenance person judges that structure is unsound. Cracks wider than inch and longer than No cracks more than 1/4 inch wide at the 1 foot at the joint of any inlet/outlet pipe or joint of inlet/outlet pipe. any evidence of soil particles entering structure through cracks. Settlement/ Structure has settled more than 1 inch or Basin replaced or repaired to design misalignment has rotated more than 2 inches out of standards. alignment. Damaged pipe joints Cracks wider than%-inch at the joint of the No cracks more than Y-inch wide at the inlet/outlet pipes or any evidence of soil joint of inlet/outlet pipes. entering the structure at the joint of the inlet/outlet pipes. Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of pollution such as oil,gasoline,concrete slurries or according to applicable regulations.Source paint. control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Ladder rungs missing Ladder is unsafe due to missing rungs, Ladder meets design standards and allows or unsafe misalignment,rust,cracks,or sharp edges. maintenance person safe access. FROP-T Section Damaged FROP-T T section is not securely attached to T section securely attached to wall and structure wall and outlet pipe structure outlet pipe. should support at least 1,000 lbs of up or down pressure. Structure is not in upright position(allow up Structure in correct position. to 10%from plumb). Page 9 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.4-CONTROL STRUCTURE/FLOW RESTRICTOR - MAINTENANCE DEFECT OR CONDITION WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPONENT PROBLEM IS NEEDED MAINTENANCE IS PERFORMED FROP-T Section Damaged FROP-T Connections to outlet pipe are not Connections to outlet pipe are water tight; (cont.) (cont.) watertight or show signs of deteriorated structure repaired or replaced and works grout. as designed. Any holes—other than designed holes—in Structure has no holes other than designed the structure. holes. Cleanout Gate Damaged or missing Cleanout gate is missing. Replace cleanout gate. cleanout gate Cleanout gate is not watertight. Gate is watertight and works as designed. Gate cannot be moved up and down by Gate moves up and down easily and is one maintenance person. watertight. Chain/rod leading to gate is missing or Chain is in place and works as designed. damaged. Orifice Plate Damaged or missing Control device is not working properly due Plate is in place and works as designed. orifice plate to missing,out of place,or bent orifice plate. Obstructions to orifice Any trash,debris,sediment,or vegetation Plate is free of all obstructions and works plate blocking the plate. as designed. Overflow Pipe Obstructions to Any trash or debris blocking(or having the Pipe is free of all obstructions and works overflow pipe potential of blocking)the overflow pipe. as designed. Deformed or Lip of overflow pipe is bent or deformed. Overflow pipe does not allow overflow at damaged lip of an elevation lower than design overflow pipe Inlet/Outlet Pipe Sediment Sediment filling 20%or more of the pipe. Inlet/outlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in No trash or debris in pipes. inlet/outlet pipes(includes floatables and non-floatables). Damaged inlet/outlet Cracks wider than%-inch at the joint of the No cracks more than'%-inch wide at the pipe inlet/outlet pipes or any evidence of soil joint of the inlet/outlet pipe. entering at the joints of the inlet/outlet pipes. Metal Grates Unsafe grate opening Grate with opening wider than inch. Grate opening meets design standards. (If applicable) Trash and debris Trash and debris that is blocking more Grate free of trash and debris.footnote to than 20%of grate surface. guidelines for disposal Damaged or missing Grate missing or broken member(s)of the Grate is in place and meets design grate grate. standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in Cover/lid protects opening to structure. place.Any open structure requires urgent maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. not working maintenance person with proper tools. Bolts cannot be seated.Self-locking cover/lid does not work. Cover/lid difficult to One maintenance person cannot remove Cover/lid can be removed and reinstalled remove cover/lid after applying 80 lbs.of lift. by one maintenance person. Page 10 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.5-CATCH BASINS AND MANHOLES MAINTENANCE DEFECT OR CONDITION WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPONENT PROBLEM IS NEEDED MAINTENANCE IS PERFORMED Structure Sediment Sediment exceeds 60%of the depth from Sump of catch basin contains no sediment. accumulation the bottom of the catch basin to the invert of the lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Trash and debris Trash or debris of more than cubic foot No Trash or debris blocking or potentially which is located immediately in front of the blocking entrance to catch basin. catch basin opening or is blocking capacity of the catch basin by more than 10%. Trash or debris in the catch basin that No trash or debris in the catch basin. exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. Dead animals or vegetation that could No dead animals or vegetation present generate odors that could cause within catch basin. complaints or dangerous gases(e.g., methane). Deposits of garbage exceeding 1 cubic No condition present which would attract or foot in volume. support the breeding of insects or rodents. Damage to frame Corner of frame extends more than%inch Frame is even with curb. and/or top slab past curb face into the street(If applicable). Top slab has holes larger than 2 square Top slab is free of holes and cracks. inches or cracks wider than'/<inch. Frame not sitting flush on top slab,i.e., Frame is sitting flush on top slab. separation of more than 3/<inch of the frame from the top slab. Cracks in walls or Cracks wider than inch and longer than Catch basin is sealed and is structurally bottom 3 feet,any evidence of soil particles sound. entering catch basin through cracks,or maintenance person judges that catch basin is unsound. Cracks wider than'%inch and longer than No cracks more than 1/4 inch wide at the 1 foot at the joint of any inlet/outlet pipe or joint of inlet/outlet pipe. any evidence of soil particles entering catch basin through cracks. Settlement/ Catch basin has settled more than 1 inch Basin replaced or repaired to design misalignment or has rotated more than 2 inches out of standards. alignment. Damaged pipe joints Cracks wider than'/2-inch at the joint of the No cracks more than'/-inch wide at the inlet/outlet pipes or any evidence of soil joint of inlet/outlet pipes. entering the catch basin at the joint of the inlet/outlet pipes. Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of pollution such as oil,gasoline,concrete slurries or according to applicable regulations.Source paint. control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment Sediment filling 20%or more of the pipe. Inlet/outlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in No trash or debris in pipes. inlet/outlet pipes(includes floatables and non-floatables). Page 11 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS • • NO.5-CATCH BASINS AND MANHOLES • MAINTENANCE DEFECT OR CONDITION WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPONENT PROBLEM IS NEEDED MAINTENANCE IS PERFORMED Inlet/Outlet Pipe Damaged inlet/outlet Cracks wider than%-inch at the joint of the No cracks more than%-inch wide at the (cont.) pipe inlet/outlet pipes or any evidence of soil joint of the inlet/outlet pipe. entering at the joints of the inlet/outlet pipes. Metal Grates Unsafe grate opening Grate with opening wider than inch. Grate opening meets design standards. (Catch Basins) Trash and debris Trash and debris that is blocking more Grate free of trash and debris.footnote to than 20%of grate surface. guidelines for disposal Damaged or missing Grate missing or broken member(s)of the Grate is in place and meets design grate grate.Any open structure requires standards. urgent maintenance. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in Cover/lid protects opening to structure. place.Any open structure requires urgent maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. not working maintenance person with proper tools. Bolts cannot be seated.Self-locking cover/lid does not work. • Cover/lid difficult to One maintenance person cannot remove Cover/lid can be removed and reinstalled remove cover/lid after applying 80 lbs.of lift. by one maintenance person. Page 12 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.6-CONVEYANCE PIPES AND DITCHES MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Pipes Sediment&debris Accumulated sediment or debris that Water flows freely through pipes. accumulation exceeds 20%of the diameter of the pipe. Vegetation/root Vegetation/roots that reduce free Water flows freely through pipes. growth in pipe movement of water through pipes. Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of pollution such as oil,gasoline,concrete slurries or according to applicable regulations.Source paint. control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective Protective coating is damaged;rust or Pipe repaired or replaced. coating or corrosion corrosion is weakening the structural integrity of any part of pipe. Damaged pipes Any dent that decreases the cross section Pipe repaired or replaced. area of pipe by more than 20%or is determined to have weakened structural integrity of the pipe. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per Trash and debris cleared from ditches. 1,000 square feet of ditch and slopes. Sediment Accumulated sediment that exceeds 20% Ditch cleaned/flushed of all sediment and accumulation of the design depth. debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which Noxious and nuisance vegetation removed may constitute a hazard to City personnel according to applicable regulations.No or the public. danger of noxious vegetation where City personnel or the public might normally be. Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of pollution such as oil,gasoline,concrete slurries or according to applicable regulations.Source paint. control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive vegetation Vegetation that reduces free movement of Water flows freely through ditches. growth water through ditches. Erosion damage to Any erosion observed on a ditch slope. Slopes are not eroding. slopes Rock lining out of One layer or less of rock exists above Replace rocks to design standards. place or missing(If native soil area 5 square feet or more,any applicable) exposed native soil. Page 13 of 42 • APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS • • NO.7-DEBRIS BARRIERS(E.G.,TRASH RACKS) MAINTENANCE DEFECT OR CONDITION WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPONENT PROBLEM IS NEEDED MAINTENANCE IS PERFORMED. Site Trash and debris Trash or debris plugging more than 20%of Barrier clear to receive capacity flow. the area of the barrier. Sediment Sediment accumulation of greater than Barrier clear to receive capacity flow. accumulation 20%of the area of the barrier Structure Cracked,broken,or Structure which bars attached to is Structure barrier attached to is sound. loose pipe or structure damaged—pipe is loose or cracked or concrete structure is cracked,broken,or loose. Bars Incorrect bar spacing Bar spacing exceeds 6 inches. Bars have at most 6 inches spacing. Damaged or missing Bars are bent out of shape more than 3 Bars in place with no bends more than' bars inches. inch. Bars are missing or entire barrier missing. Bars in place according to design. Bars are loose and rust is causing 50% Repair or replace barrier to design • deterioration to any part of barrier. standards. Page 14 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.8-ENERGY DISSIPATERS MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED. Site Trash and debris Trash and/or debris accumulation. Dissipater clear of trash and/or debris. Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of pollution such as oil,gasoline,concrete slurries or according to applicable regulations.Source paint. control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Rock Pad Missing or moved Only one layer of rock exists above native Rock pad prevents erosion. rock soil in area five square feet or larger or any exposure of native soil. Dispersion Trench Pipe plugged with Accumulated sediment that exceeds 20% Pipe cleaned/flushed so that it matches sediment of the design depth. design. Not discharging water Visual evidence of water discharging at Water discharges from feature by sheet properly concentrated points along trench(normal flow. condition is a"sheet flow'of water along trench). Perforations plugged Over 1/4 of perforations in pipe are Perforations freely discharge flow. plugged with debris or sediment. Water flows out top of Water flows out of distributor catch basin No flow discharges from distributor catch "distributor"catch during any storm less than the design basin. • basin. storm. Receiving area over- Water in receiving area is causing or has No danger of landslides. saturated potential of causing landslide problems. Gabions Damaged mesh Mesh of gabion broken,twisted or Mesh is intact,no rock missing. deformed so structure is weakened or rock may fall out. Corroded mesh Gabion mesh shows corrosion through All gabion mesh capable of containing rock more than'A of its gage. and retaining designed form. Collapsed or Gabion basket shape deformed due to any All gabion baskets intact,structure stands deformed baskets cause. as designed. Missing rock Any rock missing that could cause gabion No rock missing. to loose structural integrity. Manhole/Chamber Worn or damaged Structure dissipating flow deteriorates to 1/4 Structure is in no danger of failing. post,baffles or side of or original size or any concentrated worn chamber spot exceeding one square foot which would make structure unsound. Damage to wall, Cracks wider than'/-inch or any evidence Manhole/chamber is sealed and frame,bottom,and/or of soil entering the structure through structurally sound. top slab cracks,or maintenance inspection personnel determines that the structure is not structurally sound. Damaged pipe joints Cracks wider than 1/4-inch at the joint of the No soil or water enters and no water inlet/outlet pipes or any evidence of soil discharges at the joint of inlet/outlet pipes. entering the structure at the joint of the inlet/outlet pipes. Page 15 of 42 � J APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.9-FENCING MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Site Erosion or holes Erosion or holes more than 4 inches high No access under the fence. under fence and 12-18 inches wide permitting access through an opening under a fence. Wood Posts,Boards Missing or damaged Missing or broken boards,post out of No gaps on fence due to missing or broken and Cross Members parts plumb by more than 6 inches or cross boards,post plumb to within 1%inches, members broken cross members sound. Weakened by rotting Any part showing structural deterioration All parts of fence are structurally sound. or insects due to rotting or insect damage Damaged or failed Concrete or metal attachments Post foundation capable of supporting post foundation deteriorated or unable to support posts. posts even in strong wind. • Metal Posts,Rails Damaged parts Post out of plumb more than 6 inches. Post plumb to within 1'/s inches. and Fabric Top rails bent more than 6 inches. Top rail free of bends greater than 1 inch. Any part of fence(including post,top rails, Fence is aligned and meets design and fabric)more than 1 foot out of design standards. alignment. Missing or loose tension wire. Tension wire in place and holding fabric. Deteriorated paint or Part or parts that have a rusting or scaling Structurally adequate posts or parts with a protective coating condition that has affected structural uniform protective coating. adequacy. Openings in fabric Openings in fabric are such that an 8-inch Fabric mesh openings within 50%of grid diameter ball could fit through. size. Page 16 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO. 10-GATES/BOLLARDS/ACCESS BARRIERS MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Chain Link Fencing Damaged or missing Missing gate. Gates in place. Gate members Broken or missing hinges such that gate Hinges intact and lubed.Gate is working cannot be easily opened and closed by a freely. maintenance person. Gate is out of plumb more than 6 inches Gate is aligned and vertical. and more than 1 foot out of design alignment. Missing stretcher bar,stretcher bands,and Stretcher bar,bands,and ties in place. ties. Locking mechanism Locking device missing,no-functioning or Locking mechanism prevents opening of does not lock gate does not link to all parts. gate. Openings in fabric Openings in fabric are such that an 8-inch Fabric mesh openings within 50%of grid diameter ball could fit through. size. Bar Gate Damaged or missing Cross bar does not swing open or closed, Cross bar swings fully open and closed cross bar is missing or is bent to where it does not and prevents vehicle access. prevent vehicle access. Locking mechanism Locking device missing,no-functioning or Locking mechanism prevents opening of does not lock gate does not link to all parts. gate. Support post Support post does not hold cross bar up. Cross bar held up preventing vehicle damaged access into facility. Bollards Damaged or missing Bollard broken,missing,does not fit into No access for motorized vehicles to get bollards support hole or hinge broken or missing. into facility. Bollards do not lock Locking assembly or lock missing or No access for motorized vehicles to get cannot be attached to lock bollard in place. into facility. Boulders Dislodged boulders Boulders not located to prevent motorized No access for motorized vehicles to get vehicle access. into facility. Evidence of vehicles Motorized vehicles going around or No access for motorized vehicles to get circumventing between boulders. into facility. boulders Page 17 of 42 • APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS • NO.11 -GROUNDS(LANDSCAPING) MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic Trash and debris cleared from site. foot per 1,000 square feet(this is about equal to the amount of trash it would take to fill up one standard size office garbage can).In general,there should be no visual evidence of dumping. Noxious weeds Any noxious or nuisance vegetation which Noxious and nuisance vegetation removed may constitute a hazard to City personnel according to applicable regulations.No or the public. danger of noxious vegetation where City personnel or the public might normally be. Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of pollution such as oil,gasoline,concrete slurries or according to applicable regulations.Source paint. control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of Grass or groundcover exceeds 18 inches Grass or groundcover mowed to a height grass/groundcover in height. no greater than 6 inches. Trees and Shrubs Hazard tree identified Any tree or limb of a tree identified as No hazard trees in facility. having a potential to fall and cause property damage or threaten human life.A hazard tree identified by a qualified arborist must be removed as soon as possible. Damaged tree or Limbs or parts of trees or shrubs that are Trees and shrubs with less than 5%of total shrub identified split or broken which affect more than 25% foliage with split or broken limbs. of the total foliage of the tree or shrub. Trees or shrubs that have been blown No blown down vegetation or knocked over down or knocked over. vegetation.Trees or shrubs free of injury. Trees or shrubs which are not adequately Tree or shrub in place and adequately supported or are leaning over,causing supported;dead or diseased trees exposure of the roots. removed. Page 18 of 42 • APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.12-ACCESS ROADS: • MAINTENANCE DEFECT OR CONDITION WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPONENT PROBLEM IS NEEDED MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris exceeds 1 cubic foot per Roadway drivable by maintenance 1,000 square feet(i.e.,trash and debris vehicles. would fill up one standards size garbage can). Debris which could damage vehicle tires or Roadway drivable by maintenance prohibit use of road. vehicles. Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of pollution such as oil,gasoline,concrete slurries or according to applicable regulations.Source paint. control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Blocked roadway Any obstruction which reduces clearance Roadway overhead clear to 14 feet high. above road surface to less than 14 feet. Any obstruction restricting the access to a At least 12-foot of width on access road. 10-to 12 foot width for a distance of more than 12 feet or any point restricting access to less than a 10 foot width. Road Surface Erosion,settlement, Any surface defect which hinders or Road drivable by maintenance vehicles. potholes,soft spots, prevents maintenance access. ruts Vegetation on road Trees or other vegetation prevent access Maintenance vehicles can access facility. surface to facility by maintenance vehicles. Shoulders and Erosion Erosion within 1 foot of the roadway more Shoulder free of erosion and matching the Ditches than 8 inches wide and 6 inches deep. surrounding road. Weeds and brush Weeds and brush exceed 18 inches in Weeds and brush cut to 2 inches in height height or hinder maintenance access. or cleared in such a way as to allow maintenance access. Modular Grid Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of Pavement pollution such as oil,gasoline,concrete slurries or according to applicable regulations.Source paint. control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damaged or missing Access surface compacted because of Access road surface restored so road blocks/grids broken on missing modular block. infiltrates. • Page 19 of 42 1 • APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.21 -PROPRIETARY FACILITY CARTRIDGE FILTER SYSTEMS MAINTENANCE DEFECT OR CONDITION WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPONENT PROBLEM IS NEEDED MAINTENANCE IS PERFORMED In addition to the specific maintenance criteria provided below,all manufacturers'requirements shall be followed. Facility Documentation Update facility inspection record after each Maintenance records are up to date. inspection. Provide certification of replaced filter Filter media is certified to meet media. manufacturer specifications. Site Trash and debris Any trash or debris which impairs the Trash and debris removed from facility. function of the facility. Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of pollution such as oils,gasoline,concrete slurries or according to applicable regulations.Source paint. control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Life cycle Once per year. Facility is re-inspected and any needed maintenance performed. Vault Treatment Sediment on vault Varies—Refer to manufacturer's Vault is free of sediment. Area floor requirements. Sediment on top of Varies—Refer to manufacturer's Vault is free of sediment. cartridges requirements. Multiple scum lines Thick or multiple scum lines above top of Cause of plugging corrected,canisters above top of cartridges.Probably due to plugged replaced if necessary. cartridges canisters or underdrain manifold. Vault Structure Damage to wall, Cracks wider than'/rinch and any Vault replaced or repaired to design frame,bottom,and/or evidence of soil particles entering the specifications. top slab structure through the cracks,or qualified inspection personnel determines the vault is not structurally sound. Baffles damaged Baffles corroding,cracking warping,and/or Repair or replace baffles to specification. showing signs of failure as determined by maintenance/inspection person. Filter Media Standing water in Varies—Refer to manufacturer's No standing water in vault 24 hours after a vault requirements. rain event. Short circuiting Flows do not properly enter filter Flows go through filter media. cartridges. Underdrains and Sediment and debris Underdrains or clean-outs partially plugged Underdrains and clean-outs free of Clean-Outs or filled with sediment and/or debris. sediment and debris. Inlet/Outlet Pipe Sediment Sediment filling 20%or more of the pipe. Inlet/outlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in No trash or debris in pipes. inlet/outlet pipes(includes floatables and non-floatables). Damaged inlet/outlet Cracks wider than 1/2-inch at the joint of the No cracks more than 1/2-inch wide at the pipe inlet/outlet pipes or any evidence of soil joint of the inlet/outlet pipe. entering at the joints of the inlet/outlet pipes. Page 20 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.21 -PROPRIETARY FACILITY CARTRIDGE FILTER SYSTEMS MAINTENANCE DEFECT OR CONDITION WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPONENT PROBLEM IS NEEDED MAINTENANCE IS PERFORMED Access Manhole Cover/lid not in place Cover/lid is missing or only partially in Manhole access covered. place.Any open manhole requires immediate maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. not working maintenance person with proper tools. Bolts cannot be seated.Self-locking cover/lid does not work. Cover/lid difficult to One maintenance person cannot remove Cover/lid can be removed and reinstalled remove cover/lid after applying 80 Ibs•of lift. by one maintenance'person. Ladder rungs unsafe Missing rungs,misalignment,rust,or Ladder meets design standards.Allows cracks. maintenance person safe access. Large Access Damaged or difficult Large access doors or plates cannot be Replace or repair access door so it can Doors/Plate to open opened/removed using normal equipment. opened as designed. • Gaps,doesn't cover Large access doors not flat and/or access Doors close flat and cover access opening completely opening not completely covered. completely. Lifting Rings missing, Lifting rings not capable of lifting weight of Lifting rings sufficient to lift or remove door rusted door or plate. or plate. • Page 21 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.24-CATCH BASIN INSERT(NOT ALLOWED IN THE CITY FOR OIL CONTROL) Page 22 of 42 J � APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.28-NATIVE VEGETATED•SURFACE/NATIVE VEGETATED LANDSCAPE BMP MAINTENANCE DEFECT OR CONDITION WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPONENT PROBLEM IS NEEDED MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on the Native vegetated surface site free of any native vegetated surface/native vegetated trash or debris. landscape site. Vegetation Insufficient vegetation Less than two species each of native A minimum of two species each of native trees,shrubs,and groundcover occur in trees,shrubs,and groundcover is the design area. established and healthy. Poor vegetation Less than 90%if the required vegetated A minimum of 90%of the required coverage area has healthy growth. vegetated area has healthy growth. Undesirable Weeds,blackberry,and other undesirable Less than 10%undesirable vegetation vegetation present plants are invading more than 10%of occurs in the required native vegetated vegetated area. surface area. Vegetated Area Soil compaction Soil in the native vegetation area Less than 8%of native vegetation area is compacted. compacted. Insufficient vegetation Less than 3.5 square feet of native A minimum of 3.5 square feet of native vegetation area for every 1 square foot of vegetation area for every 1 square foot of impervious surface. impervious surface. Excess slope Slope of native vegetation area greater Slope of native growth area does not than 15%. exceed 15%. • NO.29-PERFORATED PIPE CONNECTIONS BMP MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Preventive Blocking,obstructions Debris or trash limiting flow into perforated Outfall of BMP is receiving designed flows pipe system or outfall of BMP is plugged or from perforated pipe connection. otherwise nonfunctioning. Inflow Inflow impeded Inflow into the perforated pipe is partially or Inflow to the perforated pipe is unimpeded. fully blocked or altered to prevent flow from getting into the pipe. Pipe Trench Area Surface compacted Ground surface over the perforated pipe Ground surface over the perforated pipe is trench is compacted or covered with not compacted and free of any impervious impermeable material. cover. Outflow Outflow impeded Outflow from the perforated pipe into the Outflow to the public drainage system is public drainage system is blocked. unimpeded. Outfall Area Erosion or landslides Existence of the perforated pipe is causing Perforated pipe system is sealed off and or exasperating erosion or landslides. an alternative BMP is implemented. • Page 23 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.32-RAINWATER HARVESTING BMP MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED • Preventive Insufficient storage No rain water in storage unit at the Maximum storage available at the volume beginning of the rain season. beginning of the rain season(Oct.1). Collection Area Trash and debris Trash of debris on collection area may plug Collection area clear of trash and debris. filter system Filter Restricted or plugged Filter is partially or fully plugged preventing Filter is allowing collection water into filter water from getting in to the storage unit. storage unit. NO.33-ROCK PAD BMP MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on rock pad Rock pad site free of any trash or debris. site. Rock Pad Area Insufficient rock pad Rock pad is not 2 feet by 3 feet by 6 inches Rock pad is 2 feet by 3 feet by 6 inches size thick or as designed. thick or as designed. Vegetation growth Vegetation is seen growing in or through No vegetation within rock pad area. rock pad. Rock Exposed soil Soil can be seen through the rock pad. Full thickness of the rock pad is in place, no soil visible through rock pad. NO.34-SHEET FLOW BMP MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on the Sheet flow site free of any trash or debris. sheet flow site. Sheet flow area Erosion Soil erosion occurring in sheet flow zone. Soil erosion is not occurring and rills and channels have been repaired. Concentrated flow Sheet flow is not occurring in the sheet Sheet flow area is regraded to provide flow zone. sheet flow. NO.35-SPLASH BLOCK BMP MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on the Splash block site free of any trash or splash block. debris. Splash Block Dislodged splash Splash block moved from outlet of Splash block correctly positioned to catch block downspout. discharge from downspout. Channeling Water coming off the splash block causing No erosion occurs from the splash block. erosion. Downspout water Water coming from the downspout is not Water is discharging normally to the misdirected discharging to the dispersal area. dispersal area. Page 24 of 42 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS NO.38-SOIL AMENDMENT BMP MAINTENANCE DEFECT OR CONDITIONS WHEN RESULTS EXPECTED WHEN COMPONENT PROBLEM MAINTENANCE IS NEEDED MAINTENANCE IS PERFORMED Soil Media Unhealthy vegetation Vegetation not fully covering ground Plants are healthy and appropriate for site surface or vegetation health is poor. conditions Yellowing:possible Nitrogen(N) deficiency.Poor growth:possible Phosphorous(P)deficiency.Poor flowering,spotting or curled leaves,or weak roots or stems:possible Potassium (K)deficiency. Inadequate soil In the fall,retum leaf fall and shredded Soil providing plant nutrients and structure nutrients and woody materials from the landscape to the structure site when possible Excessive vegetation Grass becomes excessively tall(greater Healthy turf-"grasscycle"(mulch-mow or growth than 10 inches);nuisance weeds and other leave the clippings)to build turf health vegetation start to take over. Weeds Preventive maintenance Avoid use of pesticides(bug and weed killers),like"weed&feed,"which damage the soil Fertilizer needed Where fertilization is needed(mainly turf Integrated Pest Management(IPM) and annual flower beds),a moderate protocols for fertilization followed •fertilization program should be used which relies on compost,natural fertilizers or slow-release synthetic balanced fertilizers Bare spots Bare spots on soil No bare spots,area covered with vegetation or mulch mixed into the underlying soil. Compaction Poor infiltration due to soil compaction No soil compaction • To remediate compaction,aerate soil,till to at least 8-inch depth,or further amend soil with compost and re-till • If areas are turf,aerate compacted areas and top dress them with 1/4 to 1/2 inch of compost to renovate them • If drainage is still slow,consider investigating alternative causes(e.g., high wet season groundwater levels, low permeability soils) • Also consider site use and protection from compacting activities Poor infiltration Soils become waterlogged,do not appear Facility infiltrating properly to be infiltrating. ErosioNScouring Erosion Areas of potential erosion are visible Causes of erosion(e.g.,concentrate flow entering area,channelization of runoff) identified and damaged area stabilized (regrade,rock,vegetation,erosion control matting).For deep channels or cuts(over 3 inches in ponding depth),temporary erosion control measures in place until permanent repairs can be made GrassNegetation Unhealthy vegetation Less than 75%of planted vegetation is Healthy vegetation.Unhealthy plants healthy with a generally good appearance. removed/replaced.Appropriate vegetation planted in terms of exposure,soil and soil moisture. Noxious Weeds Noxious weeds Listed noxious vegetation is present(refer No noxious weeds present. to current County noxious weed list). Page 25 of 42 r • • •PPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS . NO. 9-RETAINED TREES MAINTE ANCE DEFECT OR CONDITIONS WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPON T PROBLEM IS NEEDED MAINTENANCE IS PERFORMED Tree Dead or declining Dead,damaged,or declining Tree replaced per planting plan or acceptable substitute • NO.40-FILTER- ' SYSTEM - • MAINTENANCE DEFECT OR CONDITION WHEN MAINTENANCE RESULTS EXPECTED WHEN COMPONENT PROBL' IS NEEDED MAINTENANCE IS PERFORMED In addition to the specific maintenan -criteria provided below,all manufacturer's requirements shall be followed. Facility—General Life cycle Once per year,except mulch and trash j Facility is re-inspected and any needed Requirements removal twice per year maintenance performed Contaminants and Any evidence of contaminants or pollution Materials removed and disposed of pollution such as oil,gasoline,concrete slurries,or according to applicable regulations.Source saint control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet Excessive sediment or Accum.lated sediments or trash impair free Inlet should be free of obstructions allowing trash accumulation flow of :ter into system free distributed flow of water into system Mulch Cover Trash and floatable Excessive t =sh and/or debris accumulation Minimal trash or other debris on mulch debris accumulation cover.Mulch cover raked level. "Ponding"of water on "Ponding"in unit,suld be indicative of Stormwater should drain freely and evenly mulch cover clogging due to ex.-ssive fine sediment through mulch cover accumulation or spil .f petroleum oils Proprietary Filter "Pending"of water on Excessive fine sedimen sasses the mulch Stormwater should drain freely and evenly Media/ mulch cover after cover and clogs the filter •edia/vegetative through mulch cover.Replace substrate and Vegetation Substrate mulch cover has been substrate vegetation when needed maintained Vegetation Plants not growing or in Soil/mulch too wet,evidence of 'ill, Plants should be healthy and pest free poor condition incorrect plant selection,pest infe ..tion, and/or vandalism to plants Media/mulch too dry Irrigation is required Plants absent Plants absent Appropriate plants are present Excessive plant growth Excessive plant growth inhibits facility •runing and/or thinning vegetation maintains function or becomes a hazard for pedestrian p•per plant density.Appropriate plants are and vehicular circulation and safety pre ent. Structure Structure has visible Cracks wider than'A inch Struct e is sealed and structurally sound cracks Evidence of soil particles entering the structure through the cracks Page 26 of 42 C;'-NTECH® StormFilter Inspection and ENGINEERED SOLUTIONS Maintenance Procedures Page 27 of 42 � 0 Maintenance Guidelines In addition to these two activities,it is important to check The primary purpose of the Stormwater Management the condition of the StormFilter unit after major storms for StormFilter6 is to filter and prevent pollutants from entering our potential damage caused by high flows and for high sediment waterways.Like any effective filtration system, periodically these accumulation that may be caused by localized erosion in the •)Ilutants must be removed to restore the StormFilter to its full drainage area.It may be necessary to adjust the inspection/ maintenance schedule depending on the actual operating efficiency and effectiveness. conditions encountered by the system.In general, inspection Maintenance requirements and frequency are dependent on the activities can be conducted at any time,and maintenance should pollutant load characteristics of each site. Maintenance activities occur, if warranted,during dryer months in late summer to early may be required in the event of a chemical spill or due to fall. excessive sediment loading from site erosion or extreme storms. It is a good practice to inspect the system after major storm events. Maintenance Frequency The primary factor for determining frequency of maintenance for Maintenance Procedures the StormFilter is sediment loading. Although there are many effective maintenance options,we A properly functioning system will remove solids from water by believe the following procedure to be efficient,using common trapping particulates in the porous structure of the filter media equipment and existing maintenance protocols.The following inside the cartridges.The flow through the system will naturally two-step procedure is recommended:: decrease as more and more particulates are trapped.Eventually 1.Inspection the flow through the cartridges will be low enough to require • Inspection of the vault interior to determine the need for replacement.It may be possible to extend the usable span of the maintenance. cartridges by removing sediment from upstream trapping devices on a routine as-needed basis, in order to prevent material from 2.Maintenance being re-suspended and discharged to the StormFilter treatment • Cartridge replacement system. • Sediment removal The average maintenance lifecycle is approximately 1-5 years. Inspection and Maintenance Timing Site conditions greatly influence maintenance requirements. At least one scheduled inspection should take place per year with StormFilter units located in areas with erosion or active maintenance following as warranted. construction may need to be inspected and maintained more often than those with fully stabilized surface conditions. st,an inspection should be done before the winter season. buring the inspection the need for maintenance should be Regulatory requirements or a chemical spill can shift maintenance determined and, if disposal during maintenance will be required, timing as well.The maintenance frequency may be adjusted as samples of the accumulated sediments and media should be additional monitoring information becomes available during the obtained. inspection program.Areas that develop known problems should be inspected more frequently than areas that demonstrate no Second, if warranted,a maintenance(replacement of the filter problems, particularly after major storms. Ultimately,inspection cartridges and removal of accumulated sediments)should be and maintenance activities should be scheduled based on the performed during periods of dry weather. historic records and characteristics of an individual StormFilter system or site. It is recommended that the site owner develop a database to properly manage StormFilter inspection and maintenance programs.. Page 28 of 42 . a • Inspection Procedures Maintenance Decision Tree The need for maintenance is typically based on results of the The primary goal of an inspection is to assess the condition of inspection. The following Maintenance Decision Tree should be used as the cartridges relative to the level of visual sediment loading as a general guide.(Other factors,such as Regulatory Requirements,may it relates to decreased treatment capacity. It may be desirable to need to be considered) conduct this inspection during a storm to observe the relative flow through the filter cartridges. If the submerged cartridges 1. Sediment loading on the vault floor. are severely plugged,then typically large amounts of sediments a. If>4"of accumulated sediment, maintenance is will be present and very little flow will be discharged from the required. drainage pipes.If this is the case,then maintenance is warranted and the cartridges need to be replaced. 2. Sediment loading on top of the cartridge. Warning: In the case of a spill,the worker should abort a. If>1/4"of accumulation, maintenance is required. inspection activities until the proper guidance is obtained. 3. Submerged cartridges. Notify the local hazard control agency and Contech Engineered a. If>4"of static water above cartridge bottom for more Solutions immediately. than 24 hours after end of rain event, maintenance To conduct an inspection: is required.(Catch basins have standing water in the cartridge bay.) Important: Inspection should be performed by a person who is familiar with the operation and configuration of the 4. Plugged media. StormFilter treatment unit. a. If pore space between media granules is absent, • maintenance is required. 1. If applicable,set up safety equipment to protect and notify surrounding vehicle and pedestrian traffic. 5. Bypass condition. 2. Visually inspect the external condition of the unit and take a. If inspection is conducted during an average rain fall notes concerning defects/problems. event and StormFilter remains in bypass condition 3. Open the access portals to the vault and allow the system (water over the internal outlet baffle wall or submerged vent. cartridges),maintenance is required. 4. Without entering the vault,visually inspect the inside of the 6. Hazardous material release. unit,and note accumulations of liquids and solids. a. . If hazardous material release(automotive fluids or other) 5. Be sure to record the level of sediment build-up on the floor is reported,maintenance is required. of the vault,in the forebay,and on top of the cartridges. If flow is occurring, note the flow of water per drainage pipe. 7. Pronounced scum line. Record all observations. Digital pictures are valuable for a. If pronounced scum line(say>_ 1/4"thick)is present historical documentation. above top cap,maintenance is required. 6. Close and fasten the access portals. 7. Remove safety equipment. 8. If appropriate, make notes about the local drainage area relative to ongoing construction,erosion problems,or high loading of other materials to the system. 9. Discuss conditions that suggest maintenance and make decision as to weather or not maintenance is needed. Page 29 of 42 • • aintenance Des-nding on the configuration of the particular system, main':nance personnel will be required to enter the vault to perform he maintenance. Importa,t: If vault entry is required,OSHA rules for confined space ent ust be followed. Filter cartridge re.acement should occur during dry weather. It may be necessa 'o plug the filter inlet pipe if base flows is occurring. Replacement cartridges c. be delivered to the site or customers facility. Information concer ' g how to obtain the replacement cartridges is available from Co(tech Engineered Solutions. Warning: In the case of a spil,the maintenance personnel should abort maintenance activit•s until the proper guidance is obtained.Notify the local hazar. ontrol agency and Contech Engineered Solutions imme...tely. To conduct cartridge replacement and sedi ent removal maintenance: Important:Care must be used to avoid damaging the 1. If applicable,set up safety equipment to prot- t maintenance cartridges during removal and installation.The cost of personnel and pedestrians from site hazards. repairing components damaged during maintenance will be 2. Visually inspect the external condition of the unit a'd take the responsibility of the owner. notes concerning defects/problems. C. Set the used cartridge aside or load onto the hauling 3. Open the doors(access portals)to the vault and allow t•e truck. system to vent. 4. Without entering the vault,give the inside of the unit, D. Continue steps a through c until all cartridges have been including components,a general condition inspection. removed. Make notes about the external and internal condition of -thod 2: the vault.Give particular attention to recording the level of sediment build-up on the floor of the vault,in the forebay, A. This activity will require that maintenance personnel enter and on top of the internal components. e vault to remove the cartridges from the under drain 6. Using appropriate equipment offload the replacement m. Hold and place them under the vault opening for cartridges(up to 150 lbs.each)and set aside. lifting (removal). Disconnect each filter cartridge from the under. ain connector by rotating counterclockwise 1/4 of 7. Remove used cartridges from the vault using one of the a turn. '•II the loose cartridge,on edge,to a convenient following methods: spot benea the vault access. Method 1: B. Unscrew the c. ridge cap. A. This activity will require that maintenance personnel enter C. Remove the cartri.ee hood and float. the vault to remove the cartridges from the under drain manifold and place them under the vault opening for D. At location under stru.ture access,tip the cartridge on its lifting(removal). Disconnect each filter cartridge from the side. underdrain connector by rotating counterclockwise 1/4 of E. Empty the cartridge onto th;vault floor. Reassemble the a turn. Roll the loose cartridge,on edge,to a convenient empty cartridge. spot beneath the vault access. F. Set the empty,used cartridge asi.- or load onto the Using appropriate hoisting equipment,attach a cable hauling truck. from the boom,crane,or tripod to the loose cartridge. Contact Contech Engineered Solutions for suggested G. Continue steps a through e until all car idges have been attachment devices. removed. B. Remove the used cartridges(up to 250 lbs.each)from the vault. Page 30 of 42 • • 8. Remove accumulated sediment from the floor of the Material Disposal vault and from the forebay.This can most effectively be The accumulated sediment found in stormwater treatment accomplished by use of a vacuum truck. and conveyance systems must be handled and disposed of in 9. Once the sediments are removed,assess the condition of the accordance with regulatory protocols. It is possible for sediments vault and the condition of the connectors. to contain measurable concentrations of heavy metals and 10.Using the vacuum truck boom,crane,or tripod,lower and organic chemicals(such as pesticides and petroleum products). install the new cartridges.Once again,take care not to Areas with the greatest potential for high pollutant loading damage connections. include industrial areas and heavily traveled roads. 11.Close and fasten the door. Sediments and water must be disposed of in accordance with 12.Remove safety equipment. all applicable waste disposal regulations.When scheduling 13.Finally,dispose of the accumulated materials in accordance maintenance,consideration must be made for the disposal of with applicable regulations. Make arrangements to return the solid and liquid wastes.This typically requires coordination with used empty cartridges to Contech Engineered Solutions. a local landfill for solid waste disposal. For liquid waste disposal a number of options are available including a municipal vacuum truck decant facility,local waste water treatment plant or on-site treatment and discharge. Related Maintenance Activities - Performed on an as-needed basis StormFilter units are often just one of many structures in a more comprehensive stormwater drainage and treatment system. In order for maintenance of the StormFilter to be successful,it is imperative that all other components be properly maintained. The maintenance/repair of upstream facilities should be carried out prior to StormFilter maintenance activities. In addition to considering upstream facilities, it is also important to correct any problems identified in the drainage area.Drainage area concerns may include:erosion problems,heavy oil loading, and discharges of inappropriate materials. Page 31 of 42 Inspection Report Date: Personnel: • Location: System Size: System Type: Vault ❑ Cast-In-Place ❑ Linear Catch Basin ❑ Manhole ❑ Other ❑ Date: Sediment Thickn- sin Forebay: • Sediment Depth on .ult Floor: Structural Damage: Estimated Flow from Draina�a Pipes(if available): Cartridges Submerged: Yes ❑ No ❑ Depth of Standing Water: StormFilter Maintenance Activities • eck off if done and give description) ❑ Trash and Debris Removal: ❑ Minor Structural Repairs: ❑ Drainage Area Report Excessive Oil Loading: Ye' ❑ No ❑ Source: Sediment Accumulation on Pavement: Yes \\ No ❑ Source: Erosion of Landscaped Areas: Yes ❑ No ❑ Source: Items Needing Further Work: Owners should contact the local public works department and i'quire about how the department disposes of their street waste residuals. Other Comments: Review the condition reports from the previous inspection visits. Page 32 of 42 + i • StormFilter Maintenance Report Date: Personnel: Location: System Size: System Type: Vault Cast-In-Place ❑ Linear Catch Basin ❑ Manhole ❑ Other ❑ List Safety Procedu -s and Equipment Used: System Observation Months in Service: Oil in Forebay(if present): Yes ❑ No ❑ Sediment Depth in Forebay(if present): Sediment Depth on Vault Floor: Structural Damage: Drainage Area Report Excessive Oil Loading: Yes No ❑ Source: Sediment Accumulation on Pavement: Yes ❑ No MI Source: Erosion of Landscaped Areas: Yes ❑ No ource: StormFilter Cartridge Replacement Maintena e Activities Remove Trash and Debris: Yes ❑ No ❑ Details: Replace Cartridges: Yes ❑ No ❑ Details: Sediment Removed: Yes ❑ No ❑ Details: Quantity of Sediment Removed(estimate?): Minor Structural Repairs: Yes ❑ No ❑ Details: Residuals(debris,sediment)Disposal Methods: Notes: Page 33 of 42 • Maintenance and inspection guidance Maintenance procedures www.acostormbrixx.com.au It is important to note that failure to control and remove sediment build-up in stormwater tanks is the largest cause of system failure.Incorporation of a sediment bay in a StormBrixx®infiltration system, or a silt trap in a StormBrixx®retention/ detention system,can ensure the effective management of silt. The open design of ACO StormBrixx® allows the system to be inspected by remote CCTV either through the inlet connection,access chambers,inspection points or pipes at the sides of the ACO StormBrixx®system.This allows the system to be inspected for sediment build-up and enables collected sediment to be removed from the infiltration system or flushed through a retention/ detention system. In the event that a sediment bay,or silt trap,has not been incorporated with the ACO StormBrixx®system,please contact ACO Technical Services for further advice. Infiltration systems In order to periodically check the effectiveness of the StormBrixx®infiltration system,a percolation test can be carried out on the tank and compared with the original data.If there is a significant decrease in the infiltration rates,the infiltration tank should be filled via the inspection chamber to the invert level of the inlet pipe.It should then be flushed through with water in order to remove sediment and unblock the geotextile. Retention/detention systems In order to clean the ACO StormBrixx® The frequency of a maintenance procedure • sediment has the potential to carry l high levels of pollutant,it is important system,if a silt trap has not been for the tank will be determined by the vels • that any sediment removed from the incorporated,it will be necessary to inspection regime.A recommendation system is disposed of by,a licensed block the outflow control device,not the is not less than twice-yearly inspections, contractor and in accordance with • : local regulations and codes. overflow pipe,before filling the tank to the and during the first year after every • invert of the vent pipe.The tank should be significant storm event. filled and flushed as above and the water effluent removed and disposed of by a In order to minimise silt build-up,ACO suction truck with vacuum pump. recommends the use of pretreatment systems upstream of the retention/ If a silt trap has been installed,lift the detention system. access chamber cover and using a suction truck remove all water in the silt trap and jet the sump channel as required to remove all sediment. Page 34 of 42 C=:: NTECH® ENGINEERED SOLUTIONS CDS Guide Operation, Design, Performance and Maintenance Page 35 of 42 s CDS° Design Basics Using patented continuous deflective separation technology,the There are three primary methods of sizing a CDS system.The CDS system screens,separates and traps debris,sediment,and Water Quality Flow Rate Method determines which model size oil and grease from stormwater runoff.The indirect screening provides the desired removal efficiency at a given flow rate for a capability of the system allows for 100%removal of floatables defined particle size.The Rational Rainfall Method'' or the and and neutrally buoyant material without blinding. Flow and Probabilistic Method is used when a specific removal efficiency of screening controls physically separate captured solids,and the net annual sediment load is required. minimize the re-suspension and release of previously trapped pollutants.Inline units can treat up to 6 cfs,and internally bypass Typically in the Unites States,CDS systems are designed to flows in excess of 50 cfs(1416 Us).Available precast or cast-in- achieve an 80%annual solids load reduction based on lab place,offline units can treat flows from 1 to 300 cfs(28.3 to generated performance curves for a gradation with an average 8495 Lis).The pollutant removal capacity of the CDS system has particle size(d50)of 125 microns(pm).For some regulatory been proven in lab and field testing. environments,CDS systems can also be designed to achieve an 80%annual solids load reduction based on an average particle size(d50)of 75 microns(pm)or 50 microns(pm). Operation Overview Stormwater enters the diversion chamber where the diversion Water Quality Flow Rate Method weir guides the flow into the unit's separation chamber and In some cases,regulations require that a specific treatment rate, pollutants are removed from the flow.All flows up to the often referred to as the water quality design flow(WQQ),be system's treatment design capacity enter the separation chamber treated.This WQQ represents the peak flow rate from either and are treated. an event with a specific recurrence interval,e.g.the six-month Swirl concentration and screen deflection force floatables and storm,or a water quality depth,e.g. 1/2-inch(13 mm) of solids to the center of the separation chamber where 100%of rainfall. floatables and neutrally buoyant debris larger than the screen The CDS is designed to treat all flows up to the WQQ.At influent apertures are trapped. rates higher than the WQQ,the diversion weir will direct most Stormwater then moves through the separation screen,under flow exceeding the WQQ around the separation chamber.This the oil baffle and exits the system.The separation screen remains allows removal efficiency to remain relatively constant in the clog free due to continuous deflection. separation chamber and eliminates the risk of washout during • bypass flows regardless of influent flow rates. During the flow events exceeding the treatment design capacity, the diversion weir bypasses excessive flows around the separation Treatment flow rates are defined as the rate at which the CDS chamber,so captured pollutants are retained in the separation will remove a specific gradation of sediment at a specific removal cylinder, efficiency.Therefore the treatment flow rate is variable, based on the gradation and removal efficiency specified by the design engineer. GRATE INLET Rational Rainfall Method'" CLEAN OUT (CAST IRON HOOD FOR (REQUIRED) CUflB INLETOPENINGI —740 ti� ,` Differences in local climate,topography and scale make every 1 = site hydraulically unique. It is important to take these factors into DEFLECTION PAN,3 SIDED , consideration when estimating the long-term performance of (GRATE INLET DESIGN) T ,N,t _ Y). any stormwater treatment system.The Rational Rainfall Method � CRESTOF BYPASS WEIR $� (ONE EACH SIDD combines site-specific information with laboratory generated SEPARATION CYLINDER :� + ..,tom=�-"' '� performance data,and local historical precipitation records to ll - estimate removal efficiencies as accurately as possible. Y.1S �. I 1 . INLET FLUME - i l Short duration rain gauge records from across the United States —� 1 e and Canada were analyzed to determine the percent of the total 5't annual rainfall that fell at a range of intensities. US stations' �) t depths were totaled every 15 minutes,or hourly,and recorded in ;4. INLET(MULTIPLE PIPES POSSIBLE) 0.01-inch increments.Depths were recorded hourly with 1-mm resolution at Canadian stations.One trend was consistent at OUTLET . ,5 _ ,,. OIL BAFFLE I. •r:' " ' ) all sites;the vast majority of precipitation fell at low intensities TREATMENT SCREEN 4 \! and high intensitystorms contributed relativelylittle to the total f. 9 ° C. j• annual depth. SEPARATION SLAB • •'• "I�, SUMP STORAGE ii cj These intensities,along with the total drainage area and runoff ,'' coefficient for each specific site,are translated into flow rates using the Rational Rainfall Method.Since most sites are relatively small and highly impervious,the Rational Rainfall Method is appropriate. Based on the runoff flow rates calculated for each intensity,operating rates within a proposed CDS system are Page 36 of 42 • determined.Performance efficiency curve determined from full Two different gradations of silica sand material(UF Sediment scale laboratory tests on defined sediment PSDs is applied to &OK-110)were used in the CDS performance evaluation. The calculate solids removal efficiency.The relative removal efficiency particle size distributions(PSDs)of the test materials were at each operating rate is added to produce a net annual pollutant analyzed using standard method"Gradation ASTM D-422 removal efficiency estimate. "Standard Test Method for Particle-Size Analysis of Soils"by a Probabilistic Rational Method certified laboratory. The Probabilistic Rational Method is a sizing program Contech UF Sediment is a mixture of three different products produced developed to estimate a net annual sediment load reduction for by the U.S.Silica Company:"Sil-Co-Sil 106","#1 DRY"and a particular CDS model based on site size,site runoff coefficient, "20/40 Oil Frac". Particle size distribution analysis shows that regional rainfall intensity distribution,and anticipated pollutant the UF Sediment has a very fine gradation(d50= 20 to 30 pm) characteristics. covering a wide size range(Coefficient of Uniformity,C averaged at 10.6). In comparison with the hypothetical TSS gradation The Probabilistic Method is an extension of the Rational Method specified in the NJDEP(New Jersey Department of Environmental used to estimate peak discharge rates generated by storm events Protection)and NJCAT(New Jersey Corporation for Advanced of varying statistical return frequencies(e.g.2-year storm event). Technology)protocol for lab testing.,the OF Sediment covers a Under the Rational Method,an adjustment factor is used to similar range of particle size but with a finer d50(d50 for NJDEP adjust the runoff coefficient estimated for the 10-year event, is approximately 50 pm)(NJDEP,2003). correlating a known hydrologic parameter with the target storm event. The rainfall intensities vary depending on the return The OK 110 silica sand is a commercial product of U.S.Silica frequency of the storm event under consideration.In general, Sand. The particle size distribution analysis of this material,also these two frequency dependent parameters(rainfall intensity included in Figure 1,shows that 99.9%of the OK-110 sand is and runoff coefficient)increase as the return frequency increases finer than 250 microns,with a mean particle size(d50)of 106 while the drainage area remains constant. microns. The PSDs for the test material are shown in Figure 1. These intensities,along with the total drainage area and runoff 100.0 coefficient for each specific site,are translated into flow rates 90.0 — UF Sediment(Avg) --L using the Rational Method.Since most sites are relatively small 80.0 -- —=--OK 110(Avg) and highly impervious,the Rational Method is appropriate. Based 70.0 ---—o--NJCAT r-' on the runoff flow rates calculated for each intensity,operating 60.0 rates within a proposed CDS are determined.Performance 50.0 ��J T J� -~-. efficiency curve on defined sediment PSDs is applied to calculate 40.0 --- --- ��— solids removal efficiency.The relative removal efficiency at each 30.0 = r operating rate is added to produce a net annual pollutant 20.0 • — — T, removal efficiency estimate. 10.0 --• 0.0 . . . - Treatment Flow Rate 1 10 100 1000 The inlet throat area is sized to ensure that the WQQ passes Particle Size(gm) through the separation chamber at a water surface elevation equal to the crest of the diversion weir.The diversion weir Figure 1. Particle size distributions bypasses excessive flows around the separation chamber, Tests were conducted to quantify the performance of a specific thus preventing re-suspension or re-entrainment of previously captured particles. CDS unit(1.1 cfs(31.3-Ifs)design capacity)at various flow rates, ranging from 1%up to 125%of the treatment design capacity of Hydraulic Capacity the unit,using the 2400 micron screen.All tests were conducted The hydraulic capacity of a CDS system is determined by the with controlled influent concentrations of approximately 200 length and height of the diversion weir and by the maximum mg/L.Effluent samples were taken at equal time intervals allowable head in the system.Typical configurations allow across the entire duration of each test run. These samples hydraulic capacities of up to ten times the treatment flow rate. were then processed with a Dekaport Cone sample splitter to The crest of the diversion weir may be lowered and the inlet obtain representative sub-samples for Suspended Sediment throat may be widened to increase the capacity of the system Concentration(SSC)testing using ASTM D3977-97 "Standard at a given water surface elevation.The unit is designed to meet Test Methods for Determining Sediment Concentration in Water project specific hydraulic requirements. Samples",and particle size distribution analysis. Performance Results and Modeling Full-Scale Laboratory Test Results Based on the data from the University of Florida,a performance A full-scale CDS system(Model CDS2020-5B)was tested at the model was developed for the CDS system. A regression analysis was used to develop a fitting curve representative of the facility of University of Florida,Gainesville,FL. This CDS unit was scattered data points at various design flow rates.This model, evaluated under controlled laboratory conditions of influent flow which demonstrated good agreement with the laboratory data, rate and addition of sediment. can then be used to predict CDS system performance with respect Page 37 of 42 • o SSC removal for any particle size gradation,assuming the Maintenance p. ides are inorganic sandy silt. Figure 2 shows CDS predictive The CDS system should be inspected at regular intervals and per • mance for two typical particle size gradations(NJCAT maintained when necessary to ensure optimum performance. gradat.n and OK 110 sand)as a function of operating rate. The rate at which the system collects pollutants will depend more heavily on site activities than the size of the unit.For example, 100.00.— unstable soils or heavy winter sanding will cause the grit chamber 80.00 . . to fill more quickly but regular sweeping of paved surfaces will slow accumulation. 60.00 40.00 Inspection Inspection is the key to effective maintenance and is easily 20.00 '- performed. Pollutant transport and deposition may vary from OK � o.00 year to year and regular inspections will help ensure that the 0% 20% 40% •0% 80% 100% 120% 140% system is cleaned out at the appropriate time. At a minimum, %De''.n Flow Rate inspections should be performed twice per year(e.g.spring and fall)however more frequent inspections may be necessary Figure 2.CDS stormwater treatment edictive performance for in climates where winter sanding operations may lead to rapid various particle gradations as a functio of operating rate, accumulations,or in equipment washdown areas. Installations Many regulatory jurisdictions set a perform:nce standard for should also be inspected more frequently where excessive hydrodynamic devices by stating that the de es shall be capable amounts of trash are expected. of achieving an 80%removal efficiency for part les having a The visual inspection should ascertain that the system mean particle size(d50)of 125 microns(e.g.Wa ,ington State components are in working order and that there are no Department of Ecology—WASDOE-2008). The 'del can blockages or obstructions in the inlet and separation screen. be used to calculate the expected performance of suc' a PSD The inspection should also quantify the accumulation of (shown in Figure 3). The model indicates(Figure 4)that•he CDS hydrocarbons,trash,and sediment in the system. Measuring system with 2400 micron screen achieves approximately 80°° pollutant accumulation can be done with a calibrated dipstick, removal at the design(100%)flow rate,for this particle size tape measure or other measuring instrument.If absorbent distribution(d50= 125 pm). material is used for enhanced removal of hydrocarbons,the level of discoloration of the sorbent material should also be identified Partide Sze Distribution 100 !. •• • ..,. SO BO 70 60 50 ., 40 30 . 20 10 1 10 100 1000 10000 Particle Size(micron) Figure 3. WASDOE PSD CDS Utit Performance for Ecology PSD dro=125 Fun 100 • 80 • 60 40 y=-19.145x*100.92 20 R�=0.931 0- 0% 20% 40% 60% 80% 100% 120% 140% %Design Flow Rate Figure 4. Modeled performance for WASDOE PSD. page 38 of 42 r during inspection.It is useful and often required as part of an Cleaning operating permit to keep a record of each inspection. A simple Cleaning of a CDS systems should be done during dry weather form for doing so is provided. conditions when no flow is entering the system.The use of a Access to the CDS unit is typically achieved through two manhole vacuum truck is generally the most effective and convenient access covers. One opening allows for inspection and cleanout method of removing pollutants from the system.Simply remove of the separation chamber(cylinder and screen)and isolated the manhole covers and insert the vacuum hose into the sump. sump. The other allows for inspection and cleanout of sediment The system should be completely drained down and the sump captured and retained outside the screen. For deep units,a fully evacuated of sediment.The area outside the screen should single manhole access point would allows both sump cleanout also be cleaned out if pollutant build-up exists in this area. and access outside the screen. In installations where the risk of petroleum spills is small, liquid The CDS system should be cleaned when the level of sediment contaminants may not accumulate as quickly as sediment. has reached 75%of capacity in the isolated sump or when an However,the system should be cleaned out immediately in the appreciable level of hydrocarbons and trash has accumulated. event of an oil or gasoline spill.Motor oil and other hydrocarbons If absorbent material is used,it should be replaced when that accumulate on a more routine basis should be removed significant discoloration has occurred. Performance will not be when an appreciable layer has been captured.To remove these impacted until 100%of the sump capacity is exceeded however pollutants,it may be preferable to use absorbent pads since they it is recommended that the system be cleaned prior to that are usually less expensive to dispose than the oil/water emulsion for easier removal of sediment. The level of sediment is easily that may be created by vacuuming the oily layer.Trash and debris determined by measuring from finished grade down to the can be netted out to separate it from the other pollutants. The top of the sediment pile. To avoid underestimating the level of screen should be cleaned to ensure it is free of trash and debris. sediment in the chamber,the measuring device must be lowered Manhole covers should be securely seated following cleaning to the top of the sediment pile carefully. Particles at the top of activities to prevent leakage of runoff into the system from above the pile typically offer less resistance to the end of the rod than and also to ensure that proper safety precautions have been consolidated particles toward the bottom of the pile. Once this followed.Confined space entry procedures need to be followed measurement is recorded,it should be compared to the as-built drawing for the unit to determine weather the height of the if physical access is required.Disposal of all material removed sediment pile off the bottom of the sump floor exceeds 75%of from the CDS system should be done in accordance with local the total height of isolated sump. regulations. In many jurisdictions,disposal of the sediments may be handled in the same manner as the disposal of sediments removed from catch basins or deep sump manholes.Check your local regulations for specific requirements on disposal. Page 39 of 42 I ,> Diameter Distance from Water Surface Sediment Storage Capacity to Top of Sediment.Pile CDS Model ft m ft m y3 m3 CDS1515 3 0.9 3.0 0.9 0.5 0.4 CDS2015 4 1.2 3.0 0.9 0.9 0.7 CDS2015 5 1.5 3.0 0.9 1.3 1.0 CDS2020 5 . 1.5 3.5 1.1 1.3 1.0 CDS2025 5 1.5 4.0 1.2 1.3 1.0 CDS3020 . 6 1.8 4.0 1.2 2.1 1.6 CDS3025 6 1.8 4.0 1.2 2.1 1.6 CDS3030 6 , 1.8 4.6 1.4 . 2.1 1.6 CDS3035 6 1.8 5.0 1.5 2.1 1.6 CDS4030 . 8 2.4 4.6 1.4 5.6 4.3 CDS4040 8 2.4 5.7 1.7 5.6 4.3 CDS4045 8 2.4 6.2 1.9 • 5.6 4.3 CDS5640 10 3.0 6.3 1.9 8.7 6.7 CDS5653 10 , 3.0 ., 7.7 2.3 8.7 6.7 CDS5668 10 3.0 9.3 2.8 8.7 6.7 CDS5678 10 3.0 10.3 3.1 8.7 6.7 Table 1:CDS Maintenance Indicators and Sediment Storage Capacities Note:To avoid underestimating the volume of sediment in the chamber,carefully lower the measuring device to the top of the sediment pile.Finer silty particles at the top of the pile may be more difficult to feel with a measuring stick.These finer particles typically offer less resistance to the end of the rod than larger particles toward the bottom of the pile. Page 40 of 42 r • a 1 CDS Inspection & Maintenance Log CDS Model: Location: Water Floatable Describe Maintenance Date depth to Layer Maintenance Comments Personnel sediment' Thickness2 Performed • 1. The water depth to sediment is determined by taking two measurements with a stadia rod:one measurement from the manhole opening to the top of the sediment pile and the other from the manhole opening to the water surface. If the difference between these measurements is less than the values listed in table 1 the system should be cleaned out. Note:to avoid underestimating the volume of sediment in the chamber, the measuring device must be carefully lowered to the top of the sediment pile. 2. For optimum performance,the system should be cleaned out when the floating hydrocarbon layer accumulates to an appreciable thickness.In the event of an oil spill,the system should be cleaned immediately. Page 41 of 42 EXHIBIT C - LEGAL DESCRIPTION The land in the County of King, State of Washington, described as follows: BEING A PORTION OF THE SOUTHWEST QUARTER OF THE SOUTHEAST QUARTER OF SECTION 14, TOWNSHIP 23 NORTH, RANGE 5 EAST, WILLAMETTE MERIDIAN, KING COUNTY, WASHINGTON DESCRIBED AS FOLLOWS: BEGINNING AT THE SOUTHEAST CORNER OF THE WEST 30 FEET OF THE NORTH 165 FEET OF THE SOUTH HALF OF THE SOUTHWEST QUARTER OF THE SOUTHEAST QUARTER OF SECTION 14; THENCE NO°28'42"E ALONG THE EAST LINE OF SAID WEST 30 FEET A DISTANCE OF 164.93 FEET(165 FEET, DEED)TO THE NORTH LINE OF SAID NORTH 165 FEET OF THE SOUTH HALF OF THE SOUTHWEST QUARTER OF THE SOUTHEAST QUARTER; THENCE S88°27 58"E ALONG SAID NORTH LINE A DISTANCE OF 720.14 FEET TO THE WEST LINE OF THE EAST 558 FEET OF SAID NORTH 165 FEET OF THE SOUTH HALF OF THE SOUTHWEST QUARTER OF THE SOUTHEAST QUARTER; THENCE SO°25'10"W ALONG SAID WEST LINE A DISTANCE OF 164.67 FEET(165 FEET, DEED)TO THE SOUTH LINE OF SAID NORTH 165 FEET OF THE SOUTH HALF OF THE SOUTHWEST QUARTER OF THE SOUTHEAST QUARTER; THENCE N88°29'13"W ALONG SAID SOUTH LINE A DISTANCE OF 169.57 FEET TO THE NORTHEAST CORNER OF LOT 7 OF CAROLWOOD ACCORDING TO THE PLAT THEREOF RECORDED IN VOLUME 111 OF PLATS, PAGES 99 AND 100 (AFN 7908280585), RECORDS OF KING COUNTY, WASHINGTON; THENCE N1°20'59"E ALONG THE NORTHERLY PROLONGATION OF THE EAST LINE OF SAID LOT 7 A DISTANCE OF 1.00 FEET; THENCE N88°29'13"W ALONG A LINE PARALLEL WITH THE NORTH LINE OF SAID LOT A DISTANCE OF 89.00 FEET TO THE NORTHERLY PROLONGATION OF THE WEST LINE OF SAID LOT; THENCE S1°20'59"W ALONG SAID PROLONGATION A DISTANCE OF 1.00 FEET TO THE NORTHWEST CORNER OF SAID LOT; THENCE N88°29'13"W ALONG SAID SOUTH LINE OF THE NORTH 165 FEET OF THE SOUTH HALF OF THE SOUTHWEST QUARTER OF THE SOUTHEAST QUARTER A DISTANCE OF 461.74 FEET TO THE POINT OF BEGINNING. ALSO KNOWN AS PARCEL A OF BOUNDARY LINE ADJUSTMENT NO. LUA22-000228 RECORDED ON AUGUST 16, 2022 AS RECORDING NUMBER 20220816900003, IN THE OFFICIAL RECORDS OF KING COUNTY, WASHINGTON. Page 42 of 42