MAINTENENCE COVENANT PROPERTY OWNER REQUIRED TO MAINTAIN STORMWATER FACILITIES AND MEASURES (REPRESENTATIVE VERSION)

Transcription

1 MAINTENENCE COVENANT PROPERTY OWNER REQUIRED TO MAINTAIN STORMWATER FACILITIES AND MEASURES (REPRESENTATIVE VERSION) INSTRUCTIONS FOR APPLICANTS AND STAFF When d I have t cmplete this cvenant fr my prperty? This cvenant is required fr develpment activity that triggers Minimum Requirements (MR) #1 thrugh #5 (prjects that trigger MR#1 thrugh MR#5 are required t prepare an Advanced Abbreviated Plan as part f their Site Develpment Permit). AND The Advanced Abbreviated Plan includes any f the fllwing Best Management Practices (BMPs): dwnsput infiltratin, dwnsput dispersin, sheet flw dispersin, perfrated stub-ut cnnectin, biretentin, cncentrated flw dispersin, sil amendment, rain garden, shreline dispersin facility, permeable pavement, 65/10 dispersin area, r prus gravel driveway. AND The prperty wner is currently a crpratin, partnership, r ther business entity. If all these ANDs are true, this frm is required. Wh prepares this cvenant? This cvenant will be prepared by the Develpment Engineering staff that reviews the Site Develpment Permit Applicatin. I knw that the wner has t sign and ntarize this cvenant, s what is the prcess fr actually cmpleting it? 1.) At the time Develpment Engineering staff is ready t apprve the Advanced Abbreviated Plan, he/she will fill ut the first page and will identify which strmwater facilities and measures have been selected fr the site n the secnd page. 2.) Develpment Engineering staff will then attach the applicable maintenance instructins t the cvenant based n the selected strmwater facilities and measures. 3.) Develpment Engineering staff will then the cmpleted cvenant t the prperty wner. Pierce Cunty Planning and Land Services, 2401 Suth 35 th Street, Tacma, Washingtn Page 1 f 2

2 4.) The prperty wner must sign the dcument in frnt f a Ntary Public. 5.) After the dcument is signed and ntarized, the prperty wner (r agent) must recrd the dcument with the Pierce Cunty Auditr at the Pierce Cunty Annex. It shuld be nted the Auditr can nly recrd the riginal dcument. 6.) A cpy f the recrded dcument must then be delivered t the Develpment Engineering Divisin at the Develpment Center. 7.) Develpment Engineering staff will then save the dcument and/r recrding number int the PALS Plus electrnic permit system, and will release the related hld that is placed n the final building inspectin. Des this cvenant need t be recrded befre my building permit is issued? N. Hwever, it must be recrded prir t signff f the final building inspectin. In rder nt t delay the final building inspectin, it is recmmended t get the cvenant cmpleted and signed ff at the time f permit issuance r shrtly thereafter. Pierce Cunty Planning and Land Services, 2401 Suth 35 th Street, Tacma, Washingtn Page 2 f 2

3 After recrding return t: Develpment Engineering Divisin Planning and Land Services Department 2401 Suth 35 th Street Tacma, WA MAINTENANCE COVENANT PROPERTY OWNER REQUIRED TO MAINTAIN STORMWATER FACILITIES AND MEASURES (REPRESENTATIVE) Fr purpses f this agreement and fr indexing by the Auditr as required by R.C.W. Ch , the parties t this agreement are Grantr (als knwn as present wner), and Pierce Cunty, Grantee. Grantr is the wner f certain real prperty in Pierce Cunty, Washingtn, as described belw and referred t in this agreement as the Prperty. Parcel Number(s): Parcel Address: Legal Descriptin: Site Develpment Permit Number:

4 Grantr prpses t develp (cnstruct buildings, clear, grade, etc.) the Prperty. If left unmitigated, this develpment will cause pllutin f surface waters and will increase the amunt f strmwater runff that leaves the prperty. Pierce Cunty requires strmwater facilities be installed and/r strmwater measures be implemented that will prevent the pllutin f surface water and grundwater. Pierce Cunty als requires that strmwater facilities and/r measures be implemented that will prevent an increase in strmwater runff. The upkeep and maintenance f these strmwater facilities and/r measures are essential t the prtectin f the Cunty s surface and grundwater resurces, as well as dwnstream prperties. The fllwing strmwater facilities/measures are lcated n the Prperty and are intended t mitigate the impacts f the develpment: Dwnsput Infiltratin Facility Dwnsput Dispersin Sheet Flw Dispersin Perfrated Stub-Out Cnnectin Biretentin Facility Cncentrated Flw Dispersin Sil Amendment Rain Garden Shreline Dispersin Facility Permeable Pavement 65/10 Dispersin Area Prus Gravel Driveway Other In cnnectin with the Grantr s develpment, Pierce Cunty requires, and the Grantr agrees t maintain, the abve strmwater facility/measures in accrdance with the maintenance instructins attached herein. Apprved site develpment drawings and cnstructin phts fr the strmwater facility/measures fr this prperty can be viewed n the Pierce Cunty Planning and Land Services n-line permit system web site using the permit number n the frnt f this dcument. Cunty apprval must be btained prir t any mdificatin t, relcatin f, r remval f these strmwater facilities r measures. This cvenant runs with the land, and is binding n all parties having r acquiring any right, title, r interest in the Prperty. This cvenant cannt be terminated unless a ntice f cvenant terminatin is recrded by Pierce Cunty. Directr r Designee Signature Pierce Cunty Planning and Land Services

5 Signature f wner(s): Print Name: STATE OF WASHINGTON ) ) ss COUNTY OF PIERCE ) I certify that I knw r have satisfactry evidence that is the persn wh appeared befre me, and said persn acknwledged that (he/she/they) signed this instrument, n ath stated that (he/she/they) was authrized t execute the instrument and acknwledged it as the f (type f authrity e.g. fficer, trustee) (n behalf f whm instrument was executed) t be the free and vluntary act f such party fr the uses and purpses mentined in the instrument. Given under my hand and fficial seal this day f,. Ntary Public in and fr the State f Washingtn Residing at My cmmissin expires AFFIX SEAL OR STAMP ABOVE THIS LINE

6 65/10 Dispersin Area What is a 65/10 Dispersin Area? A 65/10 Dispersin Area is a frested/native vegetatin area that has nt been mdified r disturbed. 65/10 Dispersin Areas are used t cntrl the increased strmwater runff frm driveways, rfs, lawns, sidewalks, rads and ther develped areas. The 65/10 Dispersin methdlgy is typically used n parcels f land 1 acre r larger when a prperty wner des nt plan n remving existing frest and native vegetatin frm a large prtin (65% apprximately) f their prperty. The use f 65/10 Dispersin benefits a prperty wner because they d nt have the cnstructin csts assciated with ther strmwater facilities r measures, such as prus cncrete, dwnsput infiltratin, rain gardens, bifiltratin, etc. Prperty wners that chse t use 65/10 Dispersin t address the strmwater impacts f their prject must agree t retain, maintain, and prtect native vegetatin in a specific prtin f their prperty. Hw des a 65/10 Dispersin Area Wrk? 65/10 Dispersin cntrls strmwater runff thrugh infiltratin, and evaptranspiratin. 65/10 Dispersin als remves pllutants thrugh sedimentatin, filtratin, adsrptin, and phytremediatin. What if I want t remve my 65/10 Dispersin Area? This 65/10 Dispersin Area must remain in place in perpetuity, unless the prperty wner elects t btain a new site develpment permit and address the strmwater impacts f their prject by cnstructing anther type f strmwater facility r measure. A Ntice f Terminatin f Maintenance Cvenant will need t be recrded by the Cunty. What can I d in my 65/10 Dispersin Area? The area can be used fr passive recreatin such as pedestrian and bicycle trails, nature viewing areas, camping areas and ther similar activities that d nt require permanent structures, prvided that cleared areas and areas f cmpacted sil assciated with these areas are kept t a minimum. The area can cntain utilities and utility easements, but nt septic systems (utilities are defined as ptable and wastewater undergrund piping, undergrund wiring, and utility ples). Invasive, nn-native vegetatin and weeds listed n the State Nxius Weed List may be remved by clipping, hand-pulling, hand-digging, r ther methd that leaves the native vegetatin, trees, duff, and tpsil intact. Trees that are dangerus t life r prperty may be remved, but the stump must be left in place.

7 Hw d I knw where the bundaries f my 65/10 Dispersin Area are? The apprved site develpment drawings fr the prperty identify the lcatin f the 65/10 Dispersin Area. These drawings can be viewed n the Pierce Cunty Planning and Land Services n-line permit system web site using the site develpment permit number n page 1 f this dcument. What d I need t d t maintain and prtect my 65/10 Dispersin Area? A prperty wner shuld: a) understand where the bundaries f the area are lcated in relatinship t prperty lines and ther visual/cnstructed features, and b) prevent remval f existing native vegetatin frm the area, and c) prevent intrusin int area with mtrized equipment that might cmpact the grund r damage the vegetatin, and d) replant areas with native shrubs, grundcver and trees, if existing vegetatin is smehw damaged r dies.

8 Sil Amendment What is Sil Amendment? Sil amendment (r amended sils as they are smetimes called) is the intrductin f cmpst, tp sil, r anther rganic additives int the sils that have been disturbed during cnstructin. The intent f this practice is t recreate the existing duff layer that existed prir t cnstructin. Hw des Sil Amendment wrk? In cnjunctin with sil rganisms and vegetatin, undisturbed sil, r sil amended after cnstructin disturbance, prvides imprtant strmwater management functins, such as: Water infiltratin Shallw subsurface water strage and transmissin Nutrient, sediment, and pllutant adsrptin Sediment and pllutant bifiltratin Pllutant decmpsitin These functins are largely lst when develpment strips away native sil and vegetatin and replaces it with un-amended sil and sd. Mrever, withut prper amendment, disturbed landscapes can als becme pllutin-generating surfaces due t sil cmpactin; increased use f pesticides, fertilizers, and ther landscaping and husehld chemicals; the cncentratin f pet wastes; and pllutants assciated with radside litter. The practice f amending sil helps t regain strmwater functins, minimize the need fr sme landscaping chemicals (thus reducing pllutin thrugh preventin), and prvide increased treatment f pllutants and sediments (that can result frm develpment and habitatin). Hw d I maintain my Amended Sils? The fllwing are required maintenance practices fr amended sils: D Replenish the sil rganic matter by leaving leaf litter and grass clippings nsite (r by adding cmpst and mulch regularly). Prtect amended sils frm ersin r re-cmpactin by heavy equipment. D Nt Cmpact r pave ver amended sils. Use fertilizers, herbicides, r pesticides.

9 Dwnsput Infiltratin Facility What is a Dwnsput Infiltratin Facility? A dwnsput infiltratin facility is an undergrund strmwater strage area that is created by excavating a trench r deep pit (drywell) and filling it with washed drain rck. The drain rck creates vid spaces and these vid spaces temprarily stre the strmwater until it saks (infiltrates) int the sil. Strmwater runff frm building rfs is piped int the trench r drywell and distributed within it via a perfrated pipe. Hw d I maintain my Dwnsput Infiltratin Facility? The fllwing are required maintenance practices fr Dwnsput Infiltratin Facilities: D Check fr accumulated trash, debris, r sediment that impedes sheet flw r cnveyance int the trench r drywell. Remve if present. Check infiltratin trench r drywell fr mss r vegetatin grwth impedes flw and remve if present. Check fr blckages in pipes t r frm sump, trench, r drywell. Remve blckage if present. Ensure that the access lid n the catch basin (if present) is accessible and easy t pen (i.e., nt buried r missing). Check fr accumulated sediment in catch basin sump, and remve and dispse f in accrdance with slid waste requirements. Check underdrain/ perfrated pipe fr standing water. If standing water remains in the dispersin area fr mre than 3 days hurs fllwing a strm, address cause f pnding (e.g., remve sediment frm pipe). Check fr accumulated sediment and debris in drain rck r underdrain/ perfrated pipe. Remve sediment and debris. Check fr evidence f cntaminants such as il, gasline, r paint and clean as sn as pssible (Crdinate surce cntrl, remval, and/r cleanup with Pierce Cunty Surface Water Management and/r Dept. f Eclgy Spill Respnse ). D Nt Pave ver trench r drywell area. Discharge debris t the infiltratin trench frm rf cleaning practices.

10 Rain Garden What is a Rain Garden? A rain garden is a, shallw landscaped depressin, with cmpst amended native sils and adapted plants that cllects, absrbs, and filters strmwater runff frm rf tps, driveways, patis, and ther hard surfaces. Rain gardens are sized t pnd and temprarily stre strmwater runff and allw strmwater t sak int the grund. Hw des a Rain Garden Wrk? Rain gardens are designed t cntrl strmwater runff thrugh detentin, infiltratin, and evaptranspiratin. Rain gardens als remve pllutants thrugh sedimentatin, filtratin, adsrptin, and phytremediatin. Hw d I maintain my Rain Garden? The fllwing are required maintenance practices fr Rain Gardens: Remve trash r debris. Remve accumulated leaves. D Remve weeds and apply mulch as needed. Water plants during plant establishment (first 1-3 years). Water plants during drught cnditins (after 3 years). Check fr standing water: If standing water remains in the rain garden fr mre than 48 hurs fllwing a strm, address cause f pnding (fr example: remve debris r litter built up in the bttm f the rain garden). If standing water remains in the rain garden fr mre than 3 days fllwing a strm, cver all inlets, verflws, and penings with msquit screens t cntrl ptential pest activity. Check fr ersin r scur n rain garden walls and side slpes. Re-direct inflws t inlet r stabilize walls. Check fr instability f the walls and side slpes (nte: may require cnsultatin with a prfessinal engineer). Check fr sediment accumulatin r depsitin in the bttm f the rain garden. Remve sediment and eliminating sediment surce. Check fr bare spts withut mulch. Add 2-3 inches f mulch where needed.

11 Check verflw spillway fr missing rck, and replace if needed. Check inlets, utlets, and verflw fr accumulated leaves, sediment, debris, r vegetatin. Remve any leaves, sediment, debris, r vegetatin that blcks r inhibits flw. Check inlets, utlets, and verflw pipes fr damage (fr example: cracks r punctures frm rts). Repair r replace pipes as needed. Ensure that site water is being directed int the rain garden. If water is being directed away frm the inlet, recnfigure the inlet r splashblck t direct flws int the rain garden. Check fr ersin r missing rck arund the inlet and utlet. Address the cause f ersin and cver grund with rck r cbble t prtect subgrade sils. Check the vegetatin fr ptential issues (fr example: disclratin, lack f flwers, is blcking access t rain garden), and replace r address as needed. D Nt Cmpact r walk in the rain garden area. Remve installed vegetatin (unless it is blcking flws r is being replaced). Plant additinal vegetatin that is nt apprpriate fr the rain garden. Allw fr vegetatin t blck line-f-sight clearances and sidewalks. Use fertilizers, herbicides, r pesticides.

12 Biretentin Facility What is a Biretentin Facility? A Biretentin Facility is a shallw pnd that is designed by an engineer that temprarily stres and treats strmwater runff. It is designed t remve pllutants and t mitigate the peak strmwater flws caused by rfs, driveways r ther impervius surfaces. Biretentin Facilities are lined with a special sil mixture and are typically planted with water lving vegetatin. Biretentin Facilities cntrl strmwater runff thrugh detentin, retentin and evapratin. Bifiltratin Facilities remve pllutants thrugh sedimentatin, filtratin, adsrptin, and phytremediatin. There are three main types f Biretentin: Biretentin cells: Shallw depressins with a planting sil mix and a variety f plant material including trees, shrubs, grasses, and/r ther herbaceus plants. Biretentin swale: Similar t biretentin cells, hwever, biretentin swales are designed t als cnvey excess strmwater. Biretentin planters and planter bxes: Planters have an pen bttm and allw infiltratin t the subgrade. Hw d I maintain my Biretentin Facility? Biretentin Facilities are engineered systems, and sme larger r mre cmplex designs may require the assistance f prfessinal experts t perfrm maintenance inspectins and activities. If yu have questins r cncerns abut perfrming the required maintenance, cntact the Cunty fr further infrmatin. The fllwing are required maintenance practices fr Biretentin Facilities. D General Remve trash r debris. Remve accumulated leaves. Remve weeds and apply mulch as needed. Water plants during plant establishment (1-3 years). Water plants during drught cnditins (after 3 years). Check fr evidence f rdents and remve/eliminate if present. Check fr evidence f rdents and remve/eliminate if present. Check fr vandalism r damage and restre t riginal cnditins if needed.

13 Pnding Area Check fr standing water: If standing water remains in the Biretentin Facility fr mre than 48 hurs fllwing a strm, remve leaf r debris buildup, clean underdrain, investigate ther water inputs (e.g., grundwater, illicit cnnectins), and verify cntributing area. If these d nt slve the prblem, replace biretentin sil and replant the area. If standing water remains in the Biretentin FacilityMP: fr mre than 3 days fllwing a strm, cver all inlet, verflws and penings with msquit screens t cntrl ptential pest activity. Check fr ersin, scur, r cracks wider than 0.5 inch (in cncrete) n walls r side slpes. Address by stabilizing walls and side slpes r repairing/replacing cncrete. Check fr any instability f the walls and side slpes (nte: may require cnsultatin with a prfessinal engineer). Check berm betweden cells fr leaks r seeps. Plug hles r cnsult with a prfessinal engineer. Check berm fr settlement. Restre design height with additinal mulch if needed. Check fr sediment accumulatin r depsitin in the bttm f the Biretentin Facility. Remve sediment and eliminate sidement surce. Check fr bare spts withut mulch. Add 2-3 inches f mulch where needed. Ensure that side slpes d nt exceed 1H:3V (this can be a safety hazard). Inlets, Outlets, Overflw and Underdrain Ensure that site water is being directed prperly t the Biretentin Facility inlet structure. If water is being directed away frm the inlet, recnfigure the inlet r splashblck t direct flws int the Biretentin Facility. Check fr ersin (gullies/rills) arund inlets, utlets, verflw, and n side slpes. Regrade area r add rck, vegetatin, r ersin cntrl blanket. Check fr ersin r missing rck arund the inlet and utlet. Address the cause f ersin and cver grund with rck r cbble t prtect subgrade sils. Check inlets, utlets, and verflw fr accumulated leaves, sediment, debris, r vegetatin. Remve any leaves, sediment, debris, r vegetatin that blcks r inhibits flw. Check inlets, utlets, and verflw pipes fr damage and cracks r punctures greater than 0.25 inches. Repair r replace pipes as needed. Check trash rack fr missing r damaged bar screens. Repair r replace t design standards if needed. Check verflw spillway fr missing rck, and replace if needed. Check underdrain pipe fr blckage (plant rts, sediment, r debris), and remve if needed. Ensure that pipes and culverts are cvered and secured if they are hazards t children.

14 Check dams, weirs, and flw spreaders Check sediment, vegetatin, and debris accumulatin at check dam r weir. Clear blckage and eliminate surce. Check fr ersin and/r undercutting f check dam r weir. Address ersin and undercutting as needed. Check the weir, grade bard, r baffle fr settlement r damage. Restre t level psitin. Check sediment accumulatin alng flw spreader. Remve and dispse f the sediment if it blcks 35 percent r mre f the prts/ntches. Vegetatin Check vegetatin arund inlets and utlets. Remve vegetatin if within 1 ft f inlets and utlets. Check the vegetatin fr ptential issues (fr example: disclratin, lack f flwers, blcking access t Biretentin Facility), and replace r address as needed. Check fr dead standing vegetatin. Remve any dead standing vegetatin. Replace any plants with high mrtality rate with a mre apprpriate species. Ensure that large trees and shrubs d nt interfere with peratin f the basin r access fr maintenance. Prune trees r shrubs if they d interfere with peratin r access. Ensure that emergent vegetatin (vegetatin n the bttm f the Biretentin Facility) desn t blck flw f water. Remve grass r ther vegetatin clippings if accumulated t 2 inches r greater. Check vegetatin cverage. If less than 75 percent f the Biretentin Facility is cvered, replant as needed. Check fr presence f nxius weeds and remve accrding t applicable regulatins. Check irrigatin system and refer t manufacturer s instructins fr maintenance. Cntaminants Use spill preventin measures when handling r string ptential cntaminants in the vicinity. Check fr evidence f cntaminants such as il, gasline, r paint and clean as sn as pssible (Crdinate surce cntrl, remval, and/r cleanup with Pierce Cunty Surface Water Management and/r Dept. Of Eclgy Spill Respnse ).

15 D Nt Cmpact r walk in the Biretentin Facility. Cmpact biretentin sil media. Remve installed vegetatin (unless it is blcking flws r is being replaced). Plant additinal vegetatin that is nt apprpriate fr the Biretentin Facility. Allw fr vegetatin t blck line-f-sight clearances and sidewalks. Use fertilizers, herbicides, r pesticides.

16 Dwnsput Dispersin What is a Dwnsput Dispersin? Dwnsput Dispersin are gravel-filled trenches r splashblcks lcated at the rf dwnsput, which serve t spread rf runff ver vegetated areas. Hw des a Dwnsput Dispersin wrk? Dwnsput dispersin methds reduce peak flws by slwing strmwater runff entering int the cnveyance system, allwing fr sme infiltratin, and prviding sme water quality benefits. Hw d I maintain my Dwnsput Dispersin? The fllwing are required maintenance practices fr Dwnsput Dispersin methds: Check rf dwnsput fr leaves and debris and remve if present. D Ensure that the splashblck r rck pad is directed away frm the building structure. Check fr ersin r disruptin f the sil arund the splashblck r rck pad that is causing cncentrated flw (cnfined flw). Replace r restre sil if needed. Check rck pad fr adequate cverage (shuld be mre than ne layer f rck abve native sil). Add rck t meet design standards if needed. Check dispersin trench fr accumulated trash, debris, r sediment and remve and dispse f in accrdance with slid waste requirements if present. Check dispersin trench fr mss r vegetatin that impedes flw and remve if present. Check dispersin trench fr evidence f cncentrated flw (flw that is channelizing and nt evenly flwing ver the trench). Realign ntched grade bard r ther type f level spreader t prevent channelized flw, r rebuild trench t standards. Ensure that the access lid n the catch basin (if present) is accessible and easy t pen (i.e., nt buried r missing). Check fr sediment accumulatin in the sump f the catch basin r pipes frm sump t trench and remve if present. D Nt Cmpact r pave dispersal area. Use fertilizers, herbicides, r pesticides.

17 Check inlets, utlets, and verflw pipes fr damage and cracks r punctures greater than 0.25 inches. Repair r replace pipes as needed. Check fr ersin (gullies/rills) f the dispersal area. Ersin greater than 2 deep shuld be addressed by replacing tpsil/vegetatin. Check fr accumulated sediment r debris in the dispersal area that is blcking flw. Remving accumulated sediment r debris and eliminate surce. Check fr standing water. If standing water remains in the dispersal area fr mre than 3 days fllwing a strm, address cause f pnding (i.e., regrade depressins) and cver all inlets, verflws and penings with msquit screens. Check vegetatin cverage and ensure that vegetatin is healthy and watered during perids f n rain. Ensure that the vegetatin is nt blcking r inhibiting flw. Trim, weed, r replant as needed t restre flw path. Cnversely, ensure that vegetatin cverage is sufficient t prevent ersin r scur f the flw path. Check fr presence f nxius weeks and remve accrding t applicable regulatins. Check fr evidence f rdents and remve/eliminate if present.

18 Perfrated Stub-ut Cnnectins What is a Perfrated Stub-ut Cnnectin? A Perfrated Stub-ut Cnnectin cnsists f a length f perfrated pipe within a gravelfilled trench that is placed between rf dwnsputs and a stub-ut t the dwnstream drainage system. Hw des a Perfrated Stub-ut Cnnectin wrk? Rf runff is cnveyed t the perfrated stub-ut cnnectin, and infiltrates int the underlying sils. These systems prvide infiltratin during drier mnths, hwever during the wet winter mnths, they may prvide little r n flw cntrl. Hw d I maintain my Perfrated Stub-ut Cnnectin? The fllwing are required maintenance practices fr Perfrate Stub-ut Cnnectins: D Inspect perfrated stub-ut cnnectin during heavy rain t ensure that water is cnveyed t the drainage stub-ut. Replace drain rck r remve sediment and debris if present and blcking flw thrugh t the perfrated pipe. D Nt Pave ver trench area. Ensure that the access lid n the catch basin (if present) is accessible and easy t pen (i.e., nt buried r missing). Check underdrain/ perfrated pipe fr standing water. If standing water remains in the dispersin area fr mre than 3 days hurs fllwing a strm, address cause f pnding (e.g., remve sediment frm pipe). Check fr accumulated sediment and debris in drain rck r underdrain/ perfrated pipe. Remve sediment and debris. Check fr evidence f cntaminants such as il, gasline, r paint and clean as sn as pssible (Crdinate surce cntrl, remval, and/r cleanup with Pierce Cunty Surface Water Management and/r Dept. f Eclgy Spill Respnse ).

19 Permeable Pavement What is Permeable Pavement? Permeable pavement (als knwn as pervius and prus pavement) lks very much like rdinary pavement except it has small penings that allw water t pass thrugh and eventually sak int the grund. Permeable paving significantly reduces the amunt f strmwater runff cmpared t cnventinal pavement. Hw des Permeable Pavement Wrk? After water drains thrugh permeable pavement, it is held in a strage reservir bed (made up f aggregate rck, r drain rck), and then slwly saks (infiltrates) int the grund. There are fur main types f permeable pavement. Prus asphalt Pervius cement cncrete Interlcking cncrete paver blcks Open-celled paving grid systems Hw d I maintain my Permeable Pavement? Permeable pavements are engineered systems, and sme larger r mre cmplex designs may require the assistance f prfessinal experts t perfrm maintenance inspectins and activities. The fllwing are required maintenance practices fr Permeable Paving. Nte that nt all design elements will be present in all permeable pavement applicatins: D General Check adjacent areas t ensure that they are nt depsiting sil, mulch, r sediment n the permeable pavement area. Replant r stabilize adjacent pervius areas t reduce ersin if needed. Check fr fallen leaves r debris and remve if present. Check fr sediment r debris accumulatin between paver blcks, n surface f pavement, r in grid vids and remve if present. Inlet, utlet, and underdrain pipes (if present) Check inlet and utlet pipes fr clgging r damage. Repair, replace, and remve debris as needed. Check areas arund inlet and utlet pipes fr ersin (expsed sil), and eliminate cause f ersin if present. Check underdrain pipe fr plant rts, sediment, r debris. Jet clean, cut rts, and remve debris f present. Check and clean rifice (if present).

20 Prus asphalt and pervius cement cncrete Check adjacent vegetatin t ensure it is nt grwing int the permeable pavement area. Trim r remve vegetatin that encraches upn the permeable pavement area. Perfrm regular maintenance t prevent clgging with fine sediments. Use a vacuum r pwer washer with rtating brushes tw t three times annually. Prtect permeable pavement area frm any adjacent cnstructin site runff during prject cnstructin. Check fr cracks r trip hazards in the pavement area. Fr pthles r small cracks, fill with patching mixes. Fr larger cracks and settlement, cut and replace the pavement sectin as needed. Replace any cuts in the pavement (i.e., utility cuts) with the same permeable pavement material. Interlcking cncrete paver blcks Check fr any damaged r missing paver blcks. Remve damaged paver blcks and replace r repair per manufacturer s recmmendatins. Check fr settlement f surface. If settlement seems t be impeding functin f the pavement, reestablish riginal grade (may require resetting individual paver blcks). Check fr lss f gravel material between paver blcks and refill per manufacturer s instructins if needed. Open-celled paving grid with gravel r grass Check fr lss f gravel material in the gravel grid. If the gravel level is belw the plastic rings, refill per manufacturer s recmmendatins. Check fr lss f sil and/r grass material in the grass grid. Refill r replant per manufacturer s recmmendatins. Restre grwing medium, aerate the sil, and reseed r replant grass grid area as needed. Cntaminants Use spill preventin measures when handling r string ptential cntaminants in the vicinity. Check fr evidence f cntaminants such as il, gasline, r paint and clean as sn as pssible (Crdinate surce cntrl, remval, and/r cleanup with Pierce Cunty Surface Water Management and/r Dept. f Eclgy Spill Respnse ).

21 D Nt Apply sand, sealant, r deicers t the permeable pavement area. Use snw plws r stckpile plwed snw (i.e., dirty snw) n the pavement area, unless unavidable. Stckpile landscaping materials (such as mulch, sil, and cmpst) near r n the permeable pavement area.

22 Sheet Flw Dispersin What is Sheet Flw Dispersin? Sheet Flw Dispersin is the simplest methd f runff cntrl. This methd can be used fr any impervius r pervius surface that is flat r mderately slped (less than 15 percent slpe) such as driveways, sprt curts, patis, rfs withut gutters, lawns, pastures; r any situatin where cncentratin f flws can be avided. Hw d I maintain Sheet Flw Dispersin? The fllwing are required maintenance practices fr Sheet Flw Dispersin: D Check the rck pad, transitin zne, and/r dispersin trench fr the fllwing: Ersin r disruptin f the sil that is causing cncentrated flw (cnfined flw). Replace r restre sil if needed. Adequate rck cverage (shuld be mre than ne layer f rck abve native sil). Add rck t meet design standards if needed. Accumulated trash, debris, r sediment and remve and dispse f in accrdance with lcal slid waste requirements if present. Mss r vegetatin that impedes flw and remve if present. Evidence f cncentrated flw (flw that is channelizing and nt evenly dispersing ver the transitin zne). Rebuild transitin zne t standards. Check the dispersal area fr the fllwing: Ersin (gullies/rills). Ersin greater than 2 deep shuld be addressed by replacing tpsil/vegetatin. Accumulated sediment r debris that is blcking flw. Remving accumulated sediment r debris and eliminate surce. Standing water. If standing water remains fr mre than 3 days hurs fllwing a strm, address cause f pnding (i.e., regrade depressins) and cver all inlets, verflws and penings with msquit screens. D Nt Cmpact r pave dispersal area, transitin zne, r dispersin trench. Use fertilizers, herbicides, r pesticides.

23 Vegetatin cverage. Ensure that the vegetatin is nt blcking r inhibiting flw. Trim, weed, r replant as needed t restre flw path. Cnversely, ensure that vegetatin cverage is sufficient t prevent ersin r scur f the flw path. Als ensure that vegetatin is healthy and watered during perids f n rain. Check fr presence f nxius weeks and remve accrding t applicable regulatins. Check fr evidence f rdents and remve/eliminate if present.

24 Cncentrated Flw Dispersin What is Cncentrated Flw Dispersin? Cncentrated Flw Dispersin is used n cncentrated flws frm driveways r ther hard surface areas. Cncentrated flws are directed t a dispersal berm and dispersin trench, and then dispersed thrugh a vegetated flw path. Hw d I maintain my Cncentrated Flw Dispersin? The fllwing are required maintenance practices fr Cncentrated Flw Dispersin: D Check the rck pad, transitin zne, and/r dispersin trench fr the fllwing: Ersin r disruptin f the sil that is causing cncentrated flw (cnfined flw). Replace r restre sil if needed. Adequate rck cverage (shuld be mre than ne layer f rck abve native sil). Add rck t meet design standards if needed. Accumulated trash, debris, r sediment and remve and dispse f in accrdance with lcal slid waste requirements if present. Mss r vegetatin that impedes flw and remve if present. Evidence f cncentrated flw (flw that is channelizing and nt evenly dispersing ver the transitin zne). Rebuild transitin zne t standards. Check the dispersal area fr the fllwing: Ersin (gullies/rills). Ersin greater than 2 deep shuld be addressed by replacing tpsil/vegetatin. Accumulated sediment r debris that is blcking flw. Remving accumulated sediment r debris and eliminate surce. Standing water. If standing water remains fr mre than 3 days hurs fllwing a strm, address cause f pnding (i.e., regrade depressins) and cver all inlets, verflws and penings with msquit screens. D Nt Cmpact r pave dispersal area r dispersin trench. Use fertilizers, herbicides, r pesticides.

25 Vegetatin cverage. Ensure that the vegetatin is nt blcking r inhibiting flw. Trim, weed, r replant as needed t restre flw path. Cnversely, ensure that vegetatin cverage is sufficient t prevent ersin r scur f the flw path. Als ensure that vegetatin is healthy and watered during perids f n rain. Check fr presence f nxius weeks and remve accrding t applicable regulatins. Check fr evidence f rdents and remve/eliminate if present.

26 Shreline Dispersin Discharge What is Shreline Dispersin Discharge? Shre line dispersin discharge is a cllectin f strmwater runff frm rf and/r driveway that is directed t the shreline fr dispersin. Runff is cllected by rf dwnsputs and driveway catch basins then piped t a Sediment Cntrl Structure. It is then directed by pipe t the landward side f a bulkhead fr direct discharge behind the bulkhead r t the seaward side f the bulkhead t a T perfrated pipe anchred at high water mark n the bulkhead. If there is n bulkhead the T perfrated pipe is cvered with jute matt stapled t the grund then anchred t the grund with crssed rebar. Hw d I maintain the Shreline Dispersin Discharge Facility? The fllwing are required maintenance practices fr Shreline Dispersin Discharge: D Keep gutters clean frm debris, leaves r pine needs. Check catch basin lid fr trash/debris blcking mre than 20% f the inlet. Check fr sediment buildup in the sump and dispse f in accrdance with slid waste requirements. Check inside fr cracks n walls and bttm. Check inside the Sediment Cntrl Structure fr blckages in the pipes t r frm the sump. Check inside fr trash/debris n the inlet/utlet T pipe wire cvering. Check fr cracks n walls and bttm. Check fr sediment build up in the sump and dispse f in accrdance with slid waste requirements. Ensure the access lid is accessible and easy t pen. Check pipes fr cracks/dents that impedes flw r allws leaking f strmwater. If pipe is butt fused, check the fused areas fr cracks r leaks. Check pipe anchrs fr lse rebar r lse wire ties. If anchr is cncrete check the pipe strap is secure and fr cracked cement. Check perfrated T dispersin pipe fr clgged hles. Check fr lse rebar anchrs and wire ties. Check jute matting fr hles and that the staples fr matting are in place. Check that end caps are in place. Check anchrs fr T pipe when elevated t high water mark seaward f bulkhead. D Nt Discharge debris t the gutters frm rf cleaning practices.

27 Prus Gravel Driveway What is a Prus Gravel Driveway? A prus gravel driveway is a special mix f angular gravel that allws runff t perclate thrugh the gravel and int the underlying subgrade. The mix is a 1:1 blend f WSDOT Crushed Surfacing Base Curse and Pierce Cunty specified #57 rck. It lks very much like rdinary gravel except it has a larger vid cntent. Hw des Prus Gravel Wrk? The larger vid cntent (i.e. pen space within the gravel) allws water t pass thrugh the gravel and eventually sak int the grund. Prus gravel significantly reduces the amunt f strmwater runff cmpared t cnventinal impervius surfaces. Hw d I maintain my Prus Gravel? The fllwing are required maintenance practices fr prus gravels. D General Check adjacent areas t ensure that they are nt depsiting sil, mulch, r sediment n the permeable pavement area. Replant r stabilize adjacent pervius areas t reduce ersin if needed. Check fr fallen leaves r debris and remve if present. Inlet, utlet, and underdrain pipes (if present) Check inlet and utlet pipes fr clgging r damage. Repair, replace, and remve debris as needed. Check areas arund inlet and utlet pipes fr ersin (expsed sil), and eliminate cause f ersin if present. Check underdrain pipe fr plant rts, sediment, r debris. Jet clean, cut rts, and remve debris f present. Check and clean rifice (if present). Cntaminants Use spill preventin measures when handling r string ptential cntaminants in the vicinity. Check fr evidence f cntaminants such as il, gasline, r paint and clean as sn as pssible (Crdinate surce cntrl, remval, and/r cleanup with Pierce Cunty Surface Water Management and/r Dept. f Eclgy Spill Respnse ).

28 D Nt Use snw plws r stckpile plwed snw (i.e., dirty snw) n the pavement area, unless unavidable. Stckpile landscaping materials (such as mulch, sil, and cmpst) near r n the permeable pavement area.