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Home My WebLink AboutConsultant Review - 980 OSGOOD STREET 10/31/1995 MERRIMACK ENGINEERING SERVICES, INC. PROFESSIONAL ENGINEERS 0 LAND SURVEYORS 0 PLANNERS 66 PARK STREET ® ANDOVER, MASSACHUSETTS 01810 ® TEL. (508)475-3555, 373-5721 FAX(508)475-1448 October 31, 1995 Town of North Andover D Planning Board Town Hall 120 Main Street North Andover, MA 01845 ANNI BOA` Attention: Ms. Kathleen Colwell RE: North Andover Texaco/John Ferreira/Dunkin Donuts Route 125 -North Andover,Massachusetts Dear Ms. Colwell: Please find enclosed copies of revised site plans, leaching details and drainage calculations for the project which depict underground storm drainage infiltration basins proposed to be installed on the site in lieu of a direct connection to the roadway drainage system. I am sending a copy of these plans to the Conservation Commission and DPW for review and comment. Given the above, please do not hesitate to contact me should you have or comments. Very t 1 ur ME A,� NE ERING SERVICES StephenJE. t 'ur I s L.S. rojec t�c P o9ldin 4 cd Enclosure cc: Mr. John Ferreira North Andover Conservation Commission North Andover DPW I� 8'-0" xz•• I i-------------------------------------------------------------- cSTOi(/E r----------------- --------- -------, I--------------- I I 24" X 18' INSPECTION COVEFI A I I I 1 I l---------------T- 1 --_----T-- I -T----------------J I A • -_-_- . } --------------- --, - ------- - i� ------------------ -------------- ---- D ° I I I I,•e • � ' I I � 1 I I I •. 1 � I I I I 1 , i I • e l f I I � � � � ' Z4 I I l-° ° ------ ----'' ------ --------`---__ ____ , --------- _ 1 I . PLAN VIEW — • • ° R-- — —I I••� 4e o • aL L'x � � � 1-/4/. 73 — a SIDE VIEW END VIEW 3/8" SLOTS 3" 2'-9 �� ..� I •I r„•. �.. .•°I I' I 1 I I +••� I off• � ; 1 .4-_—_• ��' '',,. I 1• t 1 t.l LFLOW UNE 2 3/4"---I� f !!'/¢Z.B� SIDE SECTION VIEN END SECTION VIEW AA 88 ITEM N0. .E—FDL NOTES: T / 1. CONCRETE: 4,000 PSI MINIMUM AFTER 28 DAYS. 2. REINFORCED STEEL CONFORMS TO LATEST ASTM SPEC. 3. AVAILABLE IN N-20 LOADING. No• A,VOo vE,�, MASS' aerOeef 31 i :.v LEACHING CHAMBER CONCRETE PRODUCTS, INC. "L" FLOW DIFFUSOR P.O. BOX 520 — 773 SALEM ST., ROUTE 62 NO. WILMINGTON, MA 01887 r TEL. (508) 658-2645 FAX. (508) 658-0541 PAGE E4 r Q - ,�8O 0� MERRIMACK ENGINEE.-AG SERVICES SHEET NO. OF Professional Engineers • Land Surveyors • Planners l 66 Park Street CALCULATED SY � •K-eff L=: . DATE /a/Z 19s ANDOVER, MASSACHUSETTS 01810 (508) 475-3555 CHECKED SY DATE SCALE i ! .; yL.a�». ' . I : V {� _._..........:.......... : 1 .� Qu� ................_....._ n......... ..............:.....................:......................:......................:...........,......_............... vi ........./OC�X.1...1a4..X.;....E.. 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A ................. _ .... _ _._..............1.4..3..,...(8 t-...`7.�...1. .....�-,..../../...47....'7.1._.0 ��. .......:.............-............-............._.....................'....................... .......................... ,......._�........_.................... E2G> r^� R�� S �� tzC C / --------...._2. ?.. ... iib..`7 .._.. ..�... ...................... ......... ....... ......... V e 2.4 CIA , EwQ MMUMA MERRIMACK ENGINEERING SERVICES, INC, PROFESSIONAL ENGINEERS 0 LAND SURVEYORS 0 PLANNERS 66 PARK STREET ® ANDOVER, MASSACHUSETTS 01810 ® TEL. (508)475-3555, 373-5721 FAX(508)475-1448 November 13, 1995 Coler& Colantonio 101 Accord Park Drive, Suite One Norwell, MA 02061-1685 RE: North Andover Texaco Storm Drainage Review Gentlemen: Please find enclosed herewith a copy of a site plan and drainage calculations associated with a site plan review for the North Andover Texaco/Dunkin Donuts addition on Route 125 in North Andover, Massachusetts. Several months ago the Planning Board and Conservation Commission each approved this site plan, and relied upon the North Andover DPW review of the drainage calculations. The original proposal called for discharge of the storm drainage into the existing system which is adjacent to the site on land of Landers. Mr. Landers is now reluctant to given to the developer an easement for drainage discharge, as he previously had approved. As a result, it is now necessary to find an alternate method for discharge for storm drainage for the project site. Because this project is located within the watershed of the drinking water supply of the community, a direct discharge into the storm drainage system without some sort of pretreatment was not thought by various parties to be in the best interest of the Town. As a result, it was suggested to us that we utilize infiltration as a method to store and discharge stormwater on the site. The proposed design allows for such a system to be implemented. As a result, we submitted this proposed plan and the drainage calculations to the Planning Board and North Andover DPW for staff review, as a minor modification to the project. Ms. Kathleen Colwell has advised me that the North Andover DPW does not have sufficient staff time available to proceed with this review, although, the Town Engineer previously indicated that he would attempt to complete such a review. As a result, she has suggested that I forward these plans and calculations to you for your review and comment to the Planning Department. Coler& Colantonio November 13, 1995 Page 2 Given the above and enclosure, please do not hesitate to contact me should you have questions or comments. Very truly ours, A ME CK E 'G ERING SERVICES i Step r. S ap' ' R.L.S. Proj or i at r cd Enclosure cc: Ms. Kathleen Colwell Mr. John Ferreira MERRIMACK ENGINEERING SERVICES,INC. 66 PARK STREET ANDOVER,MASSACHUSETTS 01810 MERRIMACK ENGINEERING SERVICES, INC, PROFESSIONAL ENGINEERS 0 LAND SURVEYORS 0 PLANNERS 66 PARK STREET ® ANDOVER, MASSACHUSETTS 01810 • TEL.(508)475-3555, 373-5721 FAX(508)475-1448 March 2, 1996m, 11 S CV Mr. John Chessia Coler and Colantonio, Inc. 101 Accord Park Drive, Suite One Norwell, MA 02061-1685 RE: John Ferreira-North Andover Texaco Dear Mr. Chessia: I have reviewed your letter to the North Andover Planning Board dated February 20, 1996, based on the revised plans and drainage analysis. As a result of your comments, I have made further clarification to enhance the legibility of the plans, which admittedly are quite involved with information. Also, a topographic plan showing existing "Pre Construction" condition is submitted herewith, as requested. A test pit was dug on September 1, 1995 to verify existing soil description in the vicinity of the proposed retention/detention system. This is necessary in order to properly estimate the permeability and infiltration within the subsurface soil for the hydrologic analysis. There was 24" of fill (sandy loam), then 12" of clayey loam, then 66" of silty loam with few stones/cobbles. No water was observed in the test pit, to a depth of 102", reflective of the summer drought condition. A percolation test was performed, at a depth of 74" adjacent to the test pit, which revealed a slow to very slow perc rate of 1/4" drop in 30 minutes. Using the USDA Soil Conservation Service Manual, the soil throughout the site is PaB Paxton, fine sandy loam, Hydrologic Soil Group "C", seasonal high water table> 6', moderately slow percolation, permeability of 0.2 inches per hour, as described therein. Mr. John Chessia March 2, 1996 Page 2 A soils map is enclosed herewith. Hence, for the analysis, a 1" pipe, 10 feet long was assumedly simulated to account for infiltration based on the slow percolation rate, by estimation, for the entire area of the system: The stage-storage for the detention facility was modeled as follows: Incremental Cumulative Volume* Area Volume Elev (Sq. Ft.) (Cu.Ft.) Cu. Ft. Ac. Ft. 145.20 50 75 4480 0.102 143.71 50 145 4405 0.101 143.70 1500 2550 4260 0.098 142.0 1500 945 1710 0.022 141.37 1500 750 765 0.018 140.87 1500 15 15 0.0003 140.86 -0- -0- -0- -0- * Void volume within the pits and stone (by calculation). Outlet controls are: 1. 1"Pipe (to simulate infiltration)L= 10', S = 0.04, n= 0.013, inv. = 140.86 2. 6"Pipe, L= 15', S =0.02, N= 0.013, inv. = 140.87 This was used for Pond #1 (100 year), Pond #2 (10 year) and Pond#3 (2 year), As shown on the plan, propose 3-6" inflow pipe into the facility, using 12" x 12" x 6" tees or reducer fitting to accomplish this. A manhole cover for access at each inlet pipe location is proposed, for inspection and maintenance, which would be very seldom, in our estimation. MERRIMACK ENGINEERING SERVICES,INC. - 66 PARK STREET - ANDOVER,MASSACHUSETTS 01810 Mr. John Chessia March 2, 1996 Page 3 The curve numbers used in the analysis are based on Soil Group "C" for the various described conditions, as shown in Tables 2-2A and 2-2C (enclosed). Note that the curve number of 93 for"gravel or disturbed area" is higher than the 91 given in the chart for "newly graded areas", to account for the compaction, for clarification, and being a judgment call. The runoff flow to the proposed catch basin(CB #3 on the"Drainage System Plan" - Sheet#24 of the Drainage Report) is based on Subcatchment#12 (10 year storm design, I =4.5 in/hr), where Q = 1.2 cfs (peak flow), as shown on sheet 16 of the Drainage Report. The proposed outlet pipe from this catch basin, a 12" ductile iron pipe at S = 0.01 and n=0,012 will flow at 3.5 fps, and a 4.8" depth at peak flow, frm the chart on sheet#27 of the drainage report. The six-inch outlet pipe from the facility is proposed to be set at 2% slope, into the CB #2 at invert= 141.7, 0.1' above the 12" outlet pipe from the DMH#l. If necessary, and depending on where the existing gas main is located, this proposed drain pipe can be lowered, up to, say, 0.6 feet. In order to increase the capability of the oil/gas separator, we propose a three feet sump with a tee that extends downward 12"below the inlet invert, as you aptly recommend. Please contact me to discuss these and other items which you have addressed as we hope to complete this phase of the permitting process, as we also await the response from the Massachusetts Highway Department, in their review and permit approval process. Very truly yours, MERRIMACK ENGINEERING SERVICES ,�J�6_4w C0,462;� Robert C. Daley, P.E. Civil Engineer cd Enclosure MERRIMACK ENGINEERING SERVICES.INC. 66 PARK STREET • ANDOVER, MASSACHUSETTS 01810 a MERRIMACK ENGINEERING SERVICES, INC. PROFESSIONAL ENGINEERS 0 LAND SURVEYORS 0 PLANNERS 66 PARK STREET ® ANDOVER, MASSACHUSETTS 01810 ® TEL.(508)475-3555, 373-5721 FAX(508)475-1448 April 25, 1996 Mr. Sherman Eidleman, PE District Highway Director Commonwealth of Massachusetts Highway Department District 4 -Permits Office 519 Appleton Street Arlington, MA 02174 RE: John Ferreira North Andover Texaco Dear Mr. Eidleman: I In response to your comments in a letter dated March 14, 1996, we have addressed those issues in the appropriate manner. Refer to the revised Drainage Analysis Report submitted herewith. First, upon a brief discussion with Mr. Todd DelVecchio, MM Drainage Engineer, we have revised the drainage calculations to reflect an initial time of concentration of 5 minutes, instead of 15 minutes, which we have submitted herewith, along with the watershed subcatchment plans for Pre and Post Development. The affect on the subsurface detention facility has been recalculated and determined that the facility is sufficiently sized, whereby realizing a substantial reduction in the peak rates of runoff for the various storm events.. j The discharge of runoff from the site from pre and post development will have a minimal increase in the peak rate of runoff, and a small increase in total volume (- 2%) relative to the area contained within the contributing watershed at the point of the State Highway drainage system discharge point. This is due to the fact that the existing system of structure and pipes are, according to this conservative analysis, frequently under surcharged condition which limits the rate of flow in the pipes, particularly at the discharge point. Access to the portion of the site proposed to be developed is by an existing driveway entrance. As such, no new driveway access or redesign is proposed or warranted. r The Traffic Management Plan is contained on sheet 2 of 2 of the plan set for your review. No changes are proposed. Mr. Sherman Eidleman, PE April 25, 1996 Page 2 A copy of this revised information shall be distributed to the Town of North Andover for review by their engineering consultant and staff. Upon your review of the above, should you have any questions or comments, please contact me. Very truly yours, MERRIMACK ENGINEERING SERVICES Robert C. Daley cd Enclosure cc: Mr. John Chessia Ms. Kathleen Colwell Mr. John Ferreira MERRIMACK ENGINEERING SERVICES,INC. 66 PARK STREET • ANDOVER,MASSACHUSETTS 01810 MERRIMACK ENGINEERING SERVICES, INC, PROFESSIONAL ENGINEERS ® LAND SURVEYORS ® PLANNERS 66 PARK STREET • ANDOVER, MASSACHUSETTS 01810 TEL(508)475-3555, 373-5721 FAX(508)475-1448 July 15, 1996 Mr. John Chessia Coler and Colantonio 101 Accord Park Drive - Suite One Norwell, MA 02061-1685 RE: North Andover Texaco Dear Mr. Chessia: Relative to the subject project, and in response to your most recent letter to the North Andover Planning Board, dated May 13, 1996, this letter is written to address the items of concern. At this time, the Massachusetts Highway Department has recently issued a permit to Mr. Ferreira to perform work in the State R.O.W. (Route 125) associated with this proposed site expansion, including water service, drainage and traffic control. The following responses are in order of the numbering sequence consistent with previous correspondence: 4. Groundwater elevations were found to be at 27" and 4T' as observed in two separate monitoring wells, as Shown on the enclosed plan. The validity of assuming these depths to water, as measured, io be the actual water table is questionable. In our opinion, the subsurface detention facility as proposed would function adequately, as designed, without the stipulation that it needs to be"sealed" to prevent groundwater from being drained away into the MED drainage system. These soils, being relatively impervious and compact at optimal moisture content, are virtually not susceptible to either infiltration or exfiltration. 7. The design of the drainage pipes with fittings to allow for three (3) discharge points into the subsurface drainage system is to provide an equal distribution of runoff water, without the need for direct access at each fitting. Any maintenance, when needed, could be achieved from the catch basin by removing the gas trap, or from the access manholes near each fitting. Inside the catch basin, a 3' sump is required, which will collect any sediment, thereby preventing any buildup of sediment within the pipes. The 6" outlet control pipe from this facility shall be set at invert El:= 142.0 at the leaching pit, E1 = 141.70 at the drain manhole, which will have a 12" outlet pipe, El = 141.60, thereby allowing for a continuous downward gradient(pitch) of flow from the site toward the MHD drainage system. No impedance of flow will occur. The detention facility will retain water below El = 142 (see detail on sheet 2 of 2). It should be noted that this particular drain manhole will have a sump, thereby not requiring an invert channel. Mr. John Chessia July 15, 1996 Page 2 10. Since the design of this system includes gas traps and sumps, to prevent any need for regular maintenance, our only recommendation is that the catch basin be inspected once per year, in the spring months, to check for sediment accumulation in the sump, and for oil and gas floating at the surface. 12. Site drainage, into CB, 1.69 CFS for 10 year storm, 2.57 CFS for 100 year storm, through proposed 12" ductile iron pipe, with 0.01 1/1 (full flow capacity is 3.56 CFS), d10= 0.5', d100 = 0.63', V10 =4.5FPS, V100 =4.9FPS The 3 - 6 " pipes will each handle 0.56 CFS (full flow, V= 2.86 FPS for 10 year storm) and 0.86 CFS (under 1.5" surcharge for the 100 year storm where 2.57 CFS being equally divided among the 3 - 6" pipes, into the detention facility V=4.39 FPS. Refer to the accompanying charts, based on Hlestad Methods program, for computer output data pertaining to the above flow values. 15. The proposed 144 contour, at the catch basin, ties the existing 144 contour together, due to the slight fill requirements at that location. 16. The pitch across the parking and pavement areas is at least 0.75 per cent. The pitch along the gutter line and retaining wall toward the proposed catch basin is only 0.7%. Although at minimum slope these areas will drain positively and adequately. In instances where grading has been restricted for various reasons, similar to those encountered on this site, a '/z% minimum slope has been achieved, although not specifically recommended, particularly in large pavement areas. ' 18. Mr. Ferreira will be addressing this proposed retaining wall construction easement and the necessary work associated, including a pavement patch on the abutter's property to eliminate a potential ponding condition adjacent to the wall, on the sbutter's property. 20. The bottom of the detention facility is supposed to be level, as it will serve as a storage "compartment". Only the inlet pipes (3 - 6" pipe @ inv= 143.2) and the outlet pipe(6" @ inv= 142.0) are the variables, particularly when performing drainage calculations and pond design. Within the analysis, the invert of the 6" outlet pipe (inv= 140.9) is incorrect, as noted. The correct elevation of the pipe is inv= 142.0,.whereas the bottom of the detention facility is at elevation 140.9. This correction is made in the revised calculations, enclosed herewith. No allowance for infiltration of the volume of stored water between 142.0 and 140.9 has been taken. An assumption has been made that only 1 cubic foot of storage volume is available prior to the storm event. MERRIMACK ENGINEERING SERVICES.INC - 66 PARK STREET - ANDOVER,MASSACHUSETTS 01810 Mr. John Chessia July 15, 1996 Page 3 Given all of the above, please contact me should you have any questions or comments. Very truly yours, NIERRIMACK ENGINEERING SERVICES �-kbobert C. Daley, P.E. Civil Engineer cd Enclosure cc: Mr. John Ferreira North Andover Planning Board MERRIMACK ENGINEERING SERVICES.INC 60 PARK STREET ANDOVER,MASSACHUSE7S 01810 MERRIMACK ENGINEERING SERVICES, INC. PROFESSIONAL ENGINEERS ® LAND SURVEYORS ® PLANNERS 66 PARK STREET • ANDOVER. MASSACHUSETTS 01810 • TEL. (508)475-3555, 373-5721 • FAX(508)J75-1448 August 8, 1996 Mr. John Chessia Coler and Colantonio 101 Accord Park Drive - Suite One Norwell, MA 02061-1685 RE: North Andover Texaco Dear John: As per our discussion and agreement on August 7, 1996, we have revised the plans to reflect relocation of the 6" pipe (from the detention facility to the CB/MH), the addition of the drain manhole with 3-6" ductile iron pipes out to the detention facility, and the clarification of the 144 contour near the catch basin. The issue about the high groundwater table will be the subject of my discussion with the Mass. Highway Dept. I will contact Mr. Todd DelVecchio and Mr. Robert Boone at District 4 Office to notify them that somd groundwater at seasonal high levels will be intercepted!by this detention facility and will be discharged into the MHD drainage. The exp6cted rate of infiltration be minimal, upon completion of the proposed site work. I will request that he respond in a letter, which I will present to you. I do not anticipate that he will object to a relatively low rate and amount infiltration into the system, given the relatively impervious soils in the vicinity of the site ("Paxton' soil). In a recent'conversation with Mr. Ferreira, he indicated to me that Mr. Landers, abutter to his property, will send a letter to North Andover Planning Board stating that he will grant permission to allow Mr. Ferreira to access his property for the purpose of constructing a concrete retaining wall and related finish pavement restoration. Mr. John Chessia August 8, 1996 Page 2 Upon your review of the revised Drainage Calculations, which reflect a 1.0 cubic foot storage volume at elevation 142.0, assuming no soil permeability below this elevation, and in due consideration of the design changes, as shown on the enclosed plans, please contact me should you have any questions or comments. Very truly yours, MERRIMACK ENGINEERING SERVICES 7t Hobert C. Daley, P.E. Civil Engineer cd Enclosure cc: Mr. John Ferreira MERRIMACK ENGINEERING SERVICES. INC. 66 PARK STREET ANDOVER,MASSACHUSETTS 01810