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Home My WebLink About2023/09/15 - Operations & Maintenance Manual - - 01"UMWA I El-- M ,,,N ,,,, E ME N s s E M 0 P E RA I I N S A N II„) M A I N I E N A N C E M A N LJI A II,,,,,,, Corner Development Project at Merrimack Colle 9 e iyDyis�„�mum� �owmV aumllll� 0��'Muommouu➢ GPM , plonmn��RuNuHm�Vpu�. u `�pm le l uuu B i3 '1 5 u u u u u u m 0 el'11'1111i� ��eofih idove r n Merrimack College 315 Turnpike Street North Andover, MA 01845 978.837.5000 III�,�Y ow 101 Walnut Street PO Box 9151 Watertown, MA 02471 617.924.1770 August 17, 2023 September 15, 2023 Operations and MaintenanceI Corner DevelopmentMerrimack Table of Contents ProjectInformation...............................................................................................................iii SectionA: Source Control ..................................................................................................A-1 Section B: Spill Prevention.................................................................................................B-1 B.1 Initial Notification....................................................................................................................B-1 B.2 Further Notification.................................................................................................................B-1 B.3 Assessment— Initial Containment.....................................................................................B-4 SectionC: Snow Management...........................................................................................C-1 Section D: Maintenance of Stormwater Management Systems.................................... D-1 D.1 Pavement Systems..................................................................................................................D-1 D.1.1 Standard Asphalt Pavement...............................................................................D-1 D.2 Structural Stormwater Management Devices..............................................................D-1 D.2.1 Catch Basins/Area Drains..................................................................................D-1 D.2.2 Structural Water Quality Devices.....................................................................D-2 D.2.3 Subsurface Infiltration Basins.............................................................................D-2 D.2.4 Roof Drain Leader..................................................................................................D-3 D.3 Vegetated Stormwater Management Devices............................................................D-3 D.3.1 Vegetated Areas Maintenance..........................................................................D-3 Section E: Operations and Maintenance Plan Summary................................................ D-1 E.1 Routine Maintenance Checklists.......................................................................................D-1 E.2 Reporting and Documentation.........................................................................................D-1 E.3 Construction Practices Maintenance/ Evaluation Checklist...................................D-2 EA Long-term Maintenance/Evaluation Checklist............................................................D-3 E.5 Maintenance Checklists and Device Location Maps.................................................D-4 Section F: Product Literature.............................................................................................F-1 Section G: Maintenance Agreement..................................................................................G-1 i Table of Contents Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. ii Table of Contents Operations and Maintenance Plan I Corner Development Project at Merrimack College, Proj'oect Information Site Corner Development Project at Merrimack College 315 Turnpike StreetNorth Andover, MA 01845 Developer Greystar Development East, LLC 1 Federal Street, Suite 1804 Boston, MA 02110 857-288-1849 Facility Manager Felipe R. Schwarz Merrimack College 315 Turnpike Street North Andover, MA 01845 978-837-5459 Site Contact Name: Telephone: Cell phone: Email: iii Project Information Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. iv Project Information Operations and Maintenance Plan I Corner Development Project at Merrimack College, Section A: Source Control Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. Operations and Maintenancea lCorner Development Project at Merrimack , 01 do Source Control A comprehensive source control program will be implemented at the Corner Development site, which includes the following components: Regular pavement sweeping > Catch basin cleaning > Clearing litter from the parking area, islands, and perimeter landscape areas > Enclosure and regular maintenance of all dumpsters > Spill Prevention training A-1 Source Control Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. A-2 Source Control Operations and Maintenance Plan I Corner Development Project at Merrimack College, Section B: Spill Prevention Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. Operations and MaintenanceICorner DevelopmentMerrimack , do B Spill Prevention Spill prevention equipment and training will be provided by Greystar Development East, LLC. �n iltIIIII a�� N ' IIIII' IIIII ' IIIII o�n In the event of a spill the facility and/or construction manager or supervisor will be notified immediately. Facility Manager (name): Felipe Schwarz— Merrimack College Facility Manager (phone): 978-837-5459 Construction Manager (name) : Jacob Hawes—Greystar Development East, LLC Construction Manager (phone): 857-299-7191 The supervisor will first contact the Fire Department and then notify the Police Department, the Public Health Commission and the Conservation Commission. The Fire Department is ultimately responsible for matters of public health and safety and should be notified immediately. 0u ' Ir N ot ilfil c at ii o�n Based on the assessment from the Fire Chief, additional notification to a cleanup contractor may be made. The Massachusetts Department of Environmental Protection (DEP) and the EPA may be notified depending upon the nature and severity of the spill.The Fire Chief will be responsible for determining the level of cleanup and notification required. The attached list of emergency phone numbers shall be posted in the main construction/facility office and readily accessible to all employees.A hazardous waste spill report shall be completed as necessary using the attached form. B-1 Spill Prevention Operations i to ICorner Developmentraj ei , Emergency Notification Phone Numbers 1. FACILITY MANAGER Name: Felipe Schwarz Phone: 978-837-5459 Beeper/Cell: 978-857-1845 Home Phone: Alternate Contact: John Waters Phone: 978-895-3252 Beeper/Cell: Home Phone: 2. FIRE & POLICE DEPARTMENT Emergency: 911 3. CLEANUP CONTRACTOR Address: Phone: 4. MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL Emergency: 1-(888) 304-1133 PROTECTION (DEP) 5. NATIONAL RESPONSE CENTER Phone: (800) 424-8802 Alternate: U.S. Environmental Protection Agency Emergency: Business: 6. NORTH AN DOVER HEALTH DEPARTMENT Phone: (978) 688-9540 North Andover Conservation Commission: Phone: (978) 688-9530 B-2 Spill Prevention Operations and Maintenance Plan I Corner Development Project at Merrimack College, Hazardous Waste & Oil Spill Report Date: Time: AM/PM Exact location (Transformer#): Type of equipment: Make: Size: S/N: Weather Conditions: On or near water? ❑ Yes If es, name of body of water: ❑ No y y Type of chemical/oil spilled: Amount of chemical/oil spilled: Cause of spill: Measures taken to contain or clean up spill:ill: Amount of chemical/oil recovered: Method: Material collected as a result of cleanup: drums containing drums containing drums containing Location and method of debris disposal: Name and address of any person, firm, or corporation suffering charges:P 9 9 Procedures, method,and precautions instituted to prevent a similar occurrence from recurring: Spill reported by General Office by: Time: AM/ PM Spill reported to DEP/National Response Center b P P P Y DEP Date: Time: AM/ PM InsP ector: N RC Date: Ti me: AM/ PM I nsP ector: Additional comments: 6-3 Spill Prevention Operations and MaintenanceI Corner DevelopmentMerrimack , ��33 Asses °°° .°°°°°°°°- ��hniltiI4 iinmen't The supervisor or manager will assess the incident and initiate containment control measures with the appropriate spill containment equipment included in the spill kit kept on-site.A list of recommended spill equipment to be kept on site is included on the following page. Fire/ Police Department: 911 North Andover Health Department (978) 688-9540 North Andover Conservation (978) 688-9530 Commission: Emergency Response Equipment The following equipment and materials shall be maintained at all times and stored in a secure area for long-term emergency response need. Supplies Quantity Recommended Suppliers Sorbent Pillows/"Pigs" 2 http://www.newpig.com Item#KIT276 —mobile container with two pigs Sorbent Boom/Sock 25 feet http://www.forestry-suppliers.com Sorbent Pads 50 Lite-Dri® Absorbent 5 pounds Shovel 1 Item#33934—Shovel (or equivalent) Pry Bar 1 Item#43210—Manhole cover pick(or equivalent) Goggles 1 pair Item#23334—Goggles(or equivalent) Gloves—Heavy 1 pair Item#90926—Gloves(or equivalent) B-4 Spill Prevention Operations and Maintenance Plan I Corner Development Project at Merrimack College, Section C: Snow Management Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. Operations and MaintenanceICorner DevelopmentMerrimack , do C Snow Management Snow storage areas are shown on the attached Snow Storage Area map in Section E.5 Maintenance Checklists and Device Location Maps. Snow storage areas will be managed to prevent blockage of storm drain catch basins and stormwater drainage swales. Snow combined with sand and debris may block a storm drainage system, diminishing the infiltration capacity of the system and causing localized flooding. > Sand and debris deposited on vegetated or paved areas shall be cleared from the site and properly disposed of at the end of the snow season, no later than May 15. > Snow shall not be dumped into any waterbody, pond, or wetland resource area. C-1 Snow Management Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. C-2 Snow Management Operations and Maintenance Plan I Corner Development Project at Merrimack College, Section D: Maintenance of Stormwater Management Systems Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. Operations i e PlanICorner Development Projectat Merrimack D Maintenance of Stormwater Management S oft ystems ��'3.1 ��,',)avement Systems Standard l t µ II'° II 't > Sweep or vacuum standard asphalt pavement areas at least four times per year with a rotary brush sweeper and properly dispose of removed material. Recommended sweeping schedule: o Oct/Nov o Feb/Mar o Apr/May o Aug/Sep > More frequent sweeping of paved surfaces will result in less accumulation in catch basins, less cleaning of subsurface structures, and less disposal costs. > Check loading docks and dumpster areas frequently for spillage and/or pavement staining and clean as necessary. ��',12 Structu4�� Stormwater Management )evices D.2.11 CatchsIll II II re IIr III II The proper removal of sediments and associated pollutants and trash occurs only when catch basin inlets and sumps are cleaned out regularly. The more frequent the cleaning, the less likely sediments will be re-suspended and subsequently discharged. In addition, frequent cleaning also results in more volume available for future deposition and enhances the overall performance. As noted in the pavement Operation and Maintenance (O&M) section, more frequent sweeping of paved surfaces will result in less accumulation in catch basins, less cleaning of subsurface structures, and less disposal costs. There are five (5) catch basins and fourteen (14) area drains on the Corner Development site. These catch basins are constructed with sumps (minimum 4 feet) and hooded outlets to trap D-1 Maintenance of Stormwater Management Systems Operations i l Corner Development ProjectMerrimack debris, sediments, and floating contaminants. The area drains are constructed with sumps (minimum 2 feet). Disposal of all sediments must be in accordance with applicable local, state, and federal guidelines. Catch basin and area drains locations are included in the Stormwater BMP Location Map included in Section E.5 Maintenance Checklists and Device Location Maps. Inspections and Cleaning > All catch basins shall be inspected at least four times per year and cleaned a minimum of at least once per year. > Sediment (if more than six inches deep) and/or floatable pollutants shall be pumped from the basin and disposed of at an approved offsite facility in accordance with all applicable regulations. > Any structural damage or other indication of malfunction will be reported to the site manager and repaired as necessary > During colder periods, the catch basin grates must be kept free of snow and ice. > During warmer periods, the catch basin grates must be kept free of leaves, litter, sand, and debris. The stormwater drainage system has three (3) structural water quality devices. These are Contech CDS1515 Water Quality Units,which efficiently remove sediment and hydrocarbons from stormwater runoff. A map showing the locations is included in Maintenance Checklists and Device Location Maps. > Refer to CDS Operation, Design, Performance and Maintenance Guide included in Section F. > Inspect devices monthly for the first three months after construction. After initial three-month period, all water quality units are to be inspected at least four times per year and cleaned a minimum of at least once per year (when sediment reaches 8" in depth). > Follow manufacturer instructions and contact manufacturer if system is malfunctioning. D.23 Subsurface The subsurface infiltration/detention basins are used to detain and infiltrate roadway and rooftop runoff. There are three (3) subsurface infiltration basins on the Corner Development site.A map of the infiltration basin locations is included in Section E.5 Maintenance Checklists and Device Location Maps. D-2 Maintenance of Stormwater Management Systems Operations and Maintenancea l Corner Development ProjectMerrimack , Inspections and Cleaning > The subsurface infiltration systems will be inspected at least once each year by removing the manhole/access port covers and determining the thickness of sediment that has accumulated in the sediment removal row. > If sediment is more than six inches deep, it must be suspended via flushing with clean water and removed using a vactor truck. > Manufacturer's specifications and instructions for cleaning the sediment removal row are provided as an attachment to this section. > Emergency overflow pipes will be examined at least once each year and verified that no blockage has occurred. > System will be observed after rainfalls to see if it is properly draining. . II ' Ill n Leader Roof runoff from Proposed Building 1 and Proposed Building 2 on the Corner Development site to the subsurface infiltration units. > Perform routine roof inspections quarterly. > Keep roofs clean and free of debris. > Keep roof drainage systems clear. > Keep roof access limited to authorized personnel. Clean inlets twice per year or as necessary. Vegetated Stormwater Management ��',',)eviices .0 VegetatedII e s MaIll III" II ' II Although not a structural component of the drainage system,the maintenance of vegetated areas may affect the functioning of the stormwater management system.This includes the health/density of vegetative cover and activities such as the application and disposal of lawn and garden care products, disposal of leaves and yard trimmings and proper aeration of soils. > Inspect planted areas on a semi-annual basis and remove any litter. > Maintain planted areas adjacent to pavement to prevent soil washout. > Immediately clean any soil deposited on pavement. > Re-seed bare areas; install appropriate erosion control measures when native soil is exposed or erosion channels are forming. > Plant alternative mixture of grass species in the event of unsuccessful establishment. > The grass vegetation should be cut to a height between three and four inches. > Pesticide/Herbicide Usage— No pesticides are to be used unless a single spot treatment is required for a specific control application. D-3 Maintenance of Stormwater Management Systems Operations and Maintenance Plan I Corner Development Project at Merrimack College, > Fertilizer usage should be avoided. If deemed necessary, slow release fertilizer should be used. Fertilizer may be used to begin the establishment of vegetation in bare or damaged areas, but should not be applied on a regular basis unless necessary. > Annual application of compost amendments and aeration are recommended. D-4 Maintenance of Stormwater Management Systems Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. D-5 Maintenance of Stormwater Management Systems Operations and Maintenance Plan I Corner Development Project at Merrimack College, Section E: Operations and Maintenance Plan Summary Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. Operations and MaintenanceICorner Developmentj i ac , do E Operations and Maintenance Plan Summary This Operation and Maintenance Plan has been prepared in accordance with the Stormwater Management Policy developed by the DEP and CZM or local regulations as applicable. It specifies operational practices and drainage system maintenance requirements for the Corner Development site at Merrimack College. Requirements should be adjusted by the site manager as necessary to ensure successful functioning of system components. ��Routilne Mailatenance e ilsts Routine required maintenance is described in Sections A— D. The following checklists are to be used by the property manager to implement and document the required maintenance and inspection tasks. RepartiingIIIII The site supervisor shall be responsible for ensuring that the scheduled tasks as described in this plan are appropriately completed and recorded in the Maintenance Log.Accurate records of all inspections, routine maintenance and repairs shall be documented and these records shall be available for inspection by members of the North Andover Conservation Commission, or their designated agent, upon request. The Maintenance Log shall: > Document the completion of required maintenance tasks. Identify the person responsible for the completion of tasks. > Identify any outstanding problems, malfunctions or inconsistencies identified during the course of routine maintenance. > Document specific repairs or replacements. E-1 Operations and Maintenance Plan Summary Operations and MaintenanceI Corner DevelopmentProject ei c , Canstructil ° r IIIIIMailn"' °°° Che6V�ilst Merrimack College Corner Development- North Andover, MA Cleaning or Best Repair Needed Date of Management Inspection Date Inspector Minimum Maintenance ❑Yes/No Cleaning Performed Practice Frequency Inspected Initials and Key Items to Check (List Items) or Repair by: Hay Bales/ Weekly and Sediment build up, broken Silt Fencing after any bales or stakes rainfall Gravel Weekly and Filled voids,runoff/sediments Construction after any into street Entrance rainfall Catch Basin Weekly and Clogged or sediment build- Protection after any up at surface or in basin rainfall Diversion Weekly and Maintained,moved as Channels after any necessary to correct locations, rainfall Check for erosion or breakout Temporary Weekly and Cracking,erosion, breakout, Sedimentation after any sediment buildup, Basins rainfall contaminants Stormwater Control Manager: E-2 Operations and Maintenance Plan Summary Operations and MaintenanceI Corner Developmentof at MerrimackCollege, ang°°°° IIIII IIIII Che&V�hilst Merrimack College Corner Development - North Andover, MA Minimum Cleaning or Date of Best Maintenance Repair Cleaning Management and Key Items Inspection Date Inspector Cleaning Needed or Performed Practice to Check Frequency Inspected Initials Frequency ❑Yes/No Repair by: Street Vacuum sweeper 4X per year 4X per year* Sweeping minimum Deep Sump Remove sediment 1X 4X per year 1X per year or and Hooded per year or if>6 as necessary Catch basins inches Subsurface Remove sediment 1X 1X per year 1X per year Infiltration per year or if>6 Basins inches Roof Drains Remove debris, 4x per year 2x per year clean inlets draining roof inlet cleaning, to subsurface bed inspection roof debris as necessary Water Quality Remove sediment 1x 4x per year 1x per year or Units per year or if>8 as necessary inches * Recommend sweeping Oct/Nov,Feb/Mar,Apr/May Jul/Aug with late winter most important Stormwater Control Manager: E-3 Operations and Maintenance Plan Summary Operations and MaintenanceI Corner DevelopmentMerrimack , Maild ilsts ' IIIII These checklists are provided for the maintenance crew to photocopy and use when conducting inspections and cleaning activities to the stormwater management systems. E-4 Operations and Maintenance Plan Summary Operations and MaintenanceI Corner DevelopmentMerrimack , Maintenance Checklists E-5 Operations and Maintenance Plan Summary Operations i to I Corner Developmentraj ei , Catch Basins- Inspect 4 times per year, clean when sediment depth >6 linches or at least once per year. Sediment Cleaning Catch I nspected Depth needed Date Basin (Y/N) (inches) (Y/N) Cleaned Comments(Trash, Oil, Pet waste, Lawn Debris, Damage) A101 A103 B105 13112 13113 Area Drains— Inspect 4 times per year, clean when sediment depth >6 'Inches or at least once per year. Sediment Cleaning Area I nspected Depth needed Date Drain (Y/N) (inches) (Y/N) Cleaned Comments(Trash, Oil, Pet waste, Lawn Debris, Damage) A104 B101 B102 B106 B109 13116 13117 C101 C102 C103 C104 C105 C107 C108 Water Quality Units- Inspect 4 times per year, clean at least once per year or when sediment reaches a depth of 81nches. Water Sediment Cleaning Quality I nspected Depth needed Date Unit (Y/N) (inches) (Y/N) Cleaned Comments(Trash,Oil, Pet waste, Lawn Debris, Damage) A102 B 104 C111 E-6 Operations and Maintenance Plan Summary Operations i to I Corner Developmentraj ei , Infiltration Basins-Inspect once per year. Sediment Cleaning I nspected Depth needed Date Basin (Y/N) (inches) (Y/N) Cleaned Comments(Trash, Oil, Pet waste, Lawn Debris, Damage) SYS A SYS B SYS C Roof Runoff Downspouts- Inspect roof drams monthly, clean mlets dramling to the subsurface bed twice per year. Sediment Cleaning I nspected Depth needed Date Bldg# (Y/N) (inches) (Y/N) Cleaned Comments(Trash, Oil, Pet waste, Lawn Debris, Damage) Bldg 1 — 1 Bldg 1 —2 Bldg 2— 1 Bldg 2—2 E-7 Operations and Maintenance Plan Summary Operations and MaintenanceI Corner DevelopmentMerrimack , Device Location Map E-8 Operations and Maintenance Plan Summary \\Vhb\gb1\prof\Wat-LD\11625.34 Greystar P3 Development\cad\Id\Eng\Stormwater\1162534-BMP Location[2023-08-16].dwg .... . Legend RH T'-')RN�PIKE STREET Turn � e Street,,,,,,,Route 114 SNOW STORAGE >-(PUBLIC WAY) 11111111111"""',.........�'\'\' .......... ......... . ........ „ T CATCH BASIN AREA DRAIN ._ A AD AD WATER QUALITY UNIT Uti'Q y AD (A AD-SSPROPOSED ' BUILDING 1 ROOF DRAIN G �`�'�, L__ ...........R ..... SDI SUBSURFACE DETENTION BASIN SDBSS '> SNOW STORAGE LOCATION SS wc)u AD SS D) .............. ............ %\ RD A --, SDI ........... O O AD t Q Wc�u �e p AD CD SS ID tA e SS ................ --------------- I............. --------------- 'A GB VIA &B .� SOS A . AD �. AD - PROPOSED AD BUILDING 2t; N/F n ME RIMAQ<COLLEGE � `" MAP 24 'LOT - F3()UK 13727,PAGE o 0 SS l ,.. \.......... \""...........I -01� ............ .. .................. ..... z ........ ..\11,11\11,11,11\11-11\11-11-11\11�11\11�', ................. ,. .. ... Z", '-�_"u I "M \. \� ., . A N/F P>i,RRIMCKCOLLEGE R� MAP 2 LOT 50 1"76..... /A/ -7- ertv ., Vhb q Stormwater BMP Location Plan Figure D1 0 30 60 120 Feet Corner Development Project at Merrimack College August 17,2023 North Andover,MA Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. E-10 Operations and Maintenance Plan Summary Operations and MaintenanceI Corner Development Project at Merrimack , Snow Storage Areas Map E-11 Operations and Maintenance Plan Summary \\Vhb\gb1\proj\Wat-LD\11625.34 Greystar P3 Development\cad\Id\Eng\Stormwater\1162534-SNOW.dwg Legend TURNPIKE STREET 1 T urnpike Rreetlftute 114 (PUBLIC WAY) SNOW STORAGE - ------------------ �, .b,, PROPOSED BUILDING 1 � � -- G F_ 0 _m III I IIII III ��I -e................. r �_ �� 3y ............ ---------- �� dLY1 HYD "I'll",..........."I ........... ................ ........... . . ............ .... rI ..... . I Al e ............. .. ....... ... ....... ....... ....... I ............. � ......... I � II II�� ..................................................................................................................... .......................................................... vv_ ....... e_ � ............ ............ .......... I I........... ............................................... ....... PROPOSED ""I......... BUILDING 2 N/F q. UIL MERRIMAQ<COLLEGE MAP 24 LOT 20 - �v ",„ BOOK 15727,PAGIF E .. i� e w e h e w e \' e , v. ........................... �. N/F P>i RRIMCK COLLEGEv MAP 2 LOT 50 /V V� Ni�7(� EF. �. V �Alis.. .................. Vhb 3 Snow Storage Figure D2 0 30 60 120 Feet Corner Development Project at Merrimack College August 17,2023 North Andover,MA Operations and Maintenance Plan I Corner Development Project at Merrimack College, 0 Section F: Product Literature C%il NT CHe ENGINEERED SOLUTIONS CDS Guide Operation, Design, Performance and Maintenance ................. .................. ................ ................................................... ............. JV .. .... .. .......... /......... ........... .......... ........... "Ll 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 TM 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 Us). The pollutant removal capacity of the CDS system has particle size(d50) of 125 microns(um). 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 Operation Overview size 050) of 75 microns (um) or 50 microns (um). 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 TM CLEAN OUT (CAST IRON HOOD FOR (REQUIRED) CURB INLET OPENING) Differences in local climate, topography and scale make every j 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) any Stormwater treatment System. The Rational Rainfall Method CREST OF BYPASS WEIR (ONE EACH SIDE) combines site-specific information with laboratory generated p y SEPARATION CYLINDER � ,� ""�` performance data, and local historical precipitation records to estimate removal efficiencies as accurately as possible. INLET FLUME Short duration rain gauge records from across the United States and Canada were analyzed to determine the percent of the total annual rainfall that fell at a range of intensities. US stations D depths were totaled every 15 minutes, or hourly, and recorded in 115 INLET 0.014ch increments. Depths were recorded hourly with 1-mm (MULTIPLE PIPES POSSIBLE) resolution at Canadian stations. One trend was consistent at VNE OIL BAFFLE OUTLET � all sites; the vast majority of precipitation fell at low intensities TREATMENT SCREEN l � , and high intensity storms contributed relatively little to the total t annual depth. 11 o SEPARATION SLAB SUMP STORAGE These intensities, along with the total drainage area and runoff ,,. coefficientf r each specific site, are translatedi into flow ra tes WE ''' ''� 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 2 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-1 10)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 OF 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, 1120/40 Oil Frac". Particle size distribution analysis shows that regional rainfall intensity distribution, and anticipated pollutant the OF 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-1 10 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-1 10 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 1mO ,;.rl, coefficient for each specific site, are translated into flow rates 90,0 Sediment(Avg), using the Rational Method. Since most sites are relatively small WO K I 10(Avg) and highly impervious, the Rational Method is appropriate. Based 70, ° - on the runoff flow rates calculated for each intensity, operating 60,011, rates within a proposed CDS are determined. Performance efficiency curve on defined sediment PSDs is applied to calculate ° _0�1 solids removal efficiency. The relative removal efficiency at each 20.0 XF , operating rate is added to produce a net annual pollutant removal efficiency estimate. Treatment Flow Rate 1 10 100 1000 The inlet throat area is sized to ensure that the WQQ passes Particl 11 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-L/s) design capacity) at various flow rates, o o ranging from 1 /o up to 125/o 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 model was developed for the CDS system. A regression analysis A full-scale CDS system (Model CDS2020-5B)was tested at the 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 3 to SSC removal for any particle size gradation, assuming the Maintenance particles are inorganic sandy-silt. Figure 2 shows CDS predictive The CDS system should be inspected at regular intervals and performance for two typical particle size gradations(NJCAT gradation and OK-1 10 sand)as a function of operating rate. maintained when necessary to ensure optimum performance. The rate at which the system collects pollutants will depend more heavily on site activities than the size of the unit. For example, unstable soils or heavy winter sanding will cause the grit chamber a m�nY�mauwlrw��w mom��r 80" "' w rv„w�w w�ww�, "oil �� to fill more quickly but regular sweeping of paved surfaces will slow accumulation. . -------------------- ----..----._._.._._...._... 40 Inspection � ��. Inspection is the key to effective maintenance and is easily OK .�AT performed. Pollutant transport and deposition may vary from ,;,� �; year to year and regular inspections will help ensure that the % % % % % 100 120% 1 % system is cleaned out at the appropriate time. At a minimum, %Design FlowRate inspections should be performed twice per year(e.g. spring and fall) however more frequent inspections may be necessary Figure 2. CDS stormwater treatment predictive performance for in climates where winter sanding operations may lead to rapid various particle gradations as a function of operating rate. accumulations, or in equipment washdown areas. Installations Many regulatory jurisdictions set a performance standard for should also be inspected more frequently where excessive hydrodynamic devices by stating that the devices shall be capable amounts of trash are expected. of achieving an 80%removal efficiency for particles having a The visual inspection should ascertain that the system mean particle size(d50) of 125 microns(e.g.Washington State components are in working order and that there are no Department of Ecology—WASDOE -2008). The model can blockages or obstructions in the inlet and separation screen. be used to calculate the expected performance of such a PSD The inspection should also quantify the accumulation of (shown in Figure 3). The model indicates(Figure 4)that the 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 Particle Sze I strib i r 1 II ,,, . rnmmmmmm msmmmm mmmm >>� �r ��ta��Iw��utiYa��i�,,;� ,;��,�r�,��4,�,�r�w�A»,�.,�eP,�,!d,�Fw' ,; ,�,;�., �,,��vn��-A rnlr,O- ,�,�ri;�.»�,�,�,�A;�.»�,��Di�,�,�,;�1�� s 4 ,80 _ � _....a�.__.u. ., m o ,a w u,u,m w u, o u,m ,a m u,w u, ,➢ u, u,o u 9,9 w60 �,,,. ° ,y,.,w �u u, .�..._..�u._m.s._.._u.n. m a ,➢ w u,u,m 4 u, o u,m R m u,w u, m u, u,o o,u m R u,m a s o I M q M IW IV IC M I� IV q IV N N M IW M q II N If, 50— .......m.v......m. ...:Y:m.M.S. ,u, u. xm..,wM.w�l IR,I� n.. Iq IV q�N II:N m.m.--- W q W M W W W M W q W A N A W M W W 11 11 q p W A M A W A q q N W ......rrrrrrrrrr urrrr N «« K N N ««rrrrrrrrrrrrrrr� a N P Y N ««mIDrrrrrrrrrrrrrrmlM iM PNrrtrtrtrnYi�rvrr�l PWrr ."A rrrrrrrvX m1l m1l Mi�i�i�101« Mm «rrr�l ullm riM�mrtrtM mN m'M ««r�lYrrrrrrrrrrrrr«rM Ilmrrrrrra mIM J Ilk A q W M W W W M W q W N ti N W M W A W W g Y 9 W M W W A N 4 W I i uuum umu� N w W W W'M W W N W'#uu LII N W W W �N W W N#'#N uuum W '# W'#N P#R Mlmlmlml✓ "i uuum��mmmmdl uuum��l �I room��A uuuu� uuuuJ��mmmmmdfi uuu�al�lu 200- uum w w ro m u n w a u m w w u w n u=w w m w u�u n u u w w u u u w j nm,m,m,r mrt..... ��m'n'mrt�.... �mnn h �J 9 ,g y y.,g a!' y, 9 y, 9 u 4: ��G: ,g y, y,9 u b ,g y:,g G 9 4 4 h. ......mu�.d.aw.�.aum.m.W W W Y W v.v.m.wv.m. N. N�.# #'M W v... Rm v...m.'# W W N N Y# W .u....m.wmv..,w.vrm....a m,. ,➢ 6 ,ll A N,N,,➢OV Pc tl Q, ,�i' OV pc ,➢ Pc p,Y A,,➢,➢ a !9 Pc,➢Y U,R N, � u 6 �y y�� y u y- b y e y L 4 y u L S5 � S y/g u y L y; , a it '110 100, 1 Ow, ,DOW ParticleSize( ii ) r. Figure 3. WASDOE PSD u� ,y dw, "mmm"`1,25 �f y rs'lr��"i ailrrr 100 u :u ie r IV ro ,y u; ,y ,. .�_�.�_.,�_._..®.—®-_.,�__m,_�_.�m.,�.�__u,_.�___._.m_�,_.�,_._.�_.� .�___._.�_,��_._ M R IV IN IV ?W u u u � �40 ,n +��.". 1 R.� 1 .92 u, " �� 1�420 7� �y� y IV IV _0.931 u � r 'ILL m 64 III m P�y� Design I �FlIow Rate a 1te 1 0„ u�V Figure 4. Modeled performance for WASDOE PSD. .u; �r/ urr�,w,?w�� 4 during inspection. It is useful and often required as part of an Cleaning operating permit to keep a record of each inspection. A simple form for doing so is provided. Cleaning of a CDS systems should be done during dry weather 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 consolidated particles toward the bottom of the pile. Once this and also to ensure that proper safety precautions have been followed. Confined space entry procedures need to be followed measurement is recorded, it should be compared to the as-built if physical access is required. Disposal of all material removed drawing for the unit to determine weather the height of the from the CDS system should be done in accordance with local sediment pile off the bottom of the sump floor exceeds 75%of 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. p p m a y u I W r n y d r n � u o 4 � a N w a y1 Y i .p I � .r J x o r, 4 hd r 5 CDS 1515 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. F f 16, f w f / I i %%% i//////I%/ u /u �f r "rioya l i i j 6 CDS Inspection ♦ Maintenance Log CDS Model: Location: Water Floatable Describe Maintenance Date depth to Layer Maintenance Comments Personnel sediment' Thickness' 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. 7 SUPPORT �� ' NTECHO • Drawings and specifications are available at 1107 C • Site-specific design support is available from our engineers. ENGINEERED SOLUTIONS 800-338-1122 www.ContechES.com 92017 Contech Engineered Solutions LLC,a QUIKRETE Company Contech Engineered Solutions provides site solutions for the civil engineering industry. Contech's portfolio includes bridges,drainage,sanitary sewer,earth stabilization and stormwater treatment products. For information on other Contech division offerings,visit www.ContechES.com or call 800.338.1122 NOTHING IN THIS CATALOG SHOULD BE CONSTRUED AS A WARRANTY.APPLICATIONS SUGGESTED HEREIN ARE DESCRIBED ONLY TO HELP READERS MAKE THEIR OWN EVALUATIONS AND DECISIONS,AND ARE NEITHER GUARANTEES NOR WARRANTIES OF SUITABILITY FOR ANY APPLICATION.CONTECH MAKES NO WARRANTY WHATSOEVER,EXPRESS OR IMPLIED,RELATED TO THE APPLICATIONS,MATERIALS,COATINGS,OR PRODUCTS DISCUSSED HEREIN.ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND ALL IMPLIED WARRANTIES OF FITNESS FOR ANY PARTICULAR PURPOSE ARE DISCLAIMED BY CONTECH.SEE CONTECH'S CONDITIONS OF SALE(AVAILABLE AT WWW.CONTECHES.COM/COS)FOR MORE INFORMATION. The product(s)described may be protected by one or more of the following US patents: 5,322,629;5,624,576;5,707,527;5,759,415;5,788,848;5,985,157;6,027,639;6,350,374;6,406,218; 6,641,720;6,511,595;6,649,048;6,991,114;6,998,038;7,186,058;7,296,692;7,297,266; related foreign patents or other patents pending. OW RECYCLED cds manual 3/17 PDF tj PAPER Operations and Maintenance Plan I Corner Development Project at Merrimack College, This page intentionally left blank. Operations i ICorner Development Project at Merrimack , Operations and Maintenance Corner Development ProjectMerrimack o , 01 fo Maintenance Agreement The Owner(s) hereby agree(s)to that they have read and understood this Operations and Maintenance Plan and for the length of their ownership will follow and conduct all inspection and maintenance procedures as stated in Sections A-F at the recommended intervals, or as could be deemed necessary by any reasonable party,whichever comes first. Jeffrey Doggett,Ed.D. lle irey Doggett(Sale 26,2023 10:16 Signature Printed Name 315 Turnpike St.,North Andover,MA 01845 Address Telephone Number 9/26/23 Date