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10-006 2017 03 16 REVISED ROBERTS MEADOW BROOK CHANNEL REHAB DWGS.pdfG Z A G e o E n v i r o n m e n t a l , I n c . E n g i n e e r s a n d S c i e n t i s t s 2 4 9 V a n d e r b i l t A v e n u e N o r w o o d , M A 0 2 0 6 2 P H O N E ( 7 8 1 ) 2 7 8 - 3 7 0 0 A S N O T E D G Z A G e o E n v i r o n m e n t a l , I n c . E n g i n e e r s a n d S c i e n t i s t s w w w . g z a . c o m P R O J E C T N O . D A T E : R E V I S I O N N O . D E S I G N E D B Y : P R O J M G R : D R A W N B Y : R E V I E W E D B Y : C H E C K E D B Y : S C A L E : P R E P A R E D B Y : P R E P A R E D F O R : C O V E R S H E E T D R A W I N G M A Y 2 0 1 6 1 7 2 0 2 9 . 0 0 1 C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S E D M C H E C K E D B Y : R O B E R T S M E A D O W B R O O K C H A N N E L R E H A B I L I T A T I O N P R O J E C T N O R T H A M P T O N , M A S S A C H U S E T T S M A T M A T C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S J G D T E J H A Z A R D M I T I G A T I O N G R A N T P R O G R A M ( H M G P ) "A F e d e r a l , S t a t e , a n d L o c a l P a r t n e r s h i p t h r o u g h t h e F e d e r a l E m e r g e n c y M a n a g e m e n t A g e n c y ( F E M A ) " H M G P G R A N T N U M B E R 1 8 9 5 - 0 7 C o m m o n w e a l t h o f M a s s a c h u s e t t s C H A R L I E B A K E R , G O V E R N O R M a s s a c h u s e t t s E m e r g e n c y M a n a g e m e n t A g e n c y K U R T N . S C H W A R T Z , D I R E C T O R D e p a r t m e n t o f C o n s e r v a t i o n a n d R e c r e a t i o n L E O R O Y , C O M M I S S I O N E R 1 " = 2 0 ' G Z A G e o E n v i r o n m e n t a l , I n c . E n g i n e e r s a n d S c i e n t i s t s w w w . g z a . c o m P R O J E C T N O . D A T E : R E V I S I O N N O . D E S I G N E D B Y : P R O J M G R : D R A W N B Y : R E V I E W E D B Y : C H E C K E D B Y : S C A L E : P R E P A R E D B Y : P R E P A R E D F O R : E X I S T I N G C O N D I T I O N S P L A N D R A W I N G N G R A P H I C S C A L E 0 1 0 2 0 4 0 S C A L E I N F E E T “ ” “ ” M A Y 2 0 1 6 1 7 2 0 2 9 . 0 0 2 C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S E D M C H E C K E D B Y : R O B E R T S M E A D O W B R O O K C H A N N E L R E H A B I L I T A T I O N P R O J E C T N O R T H A M P T O N , M A S S A C H U S E T T S M A T M A T C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S J G D T E J M A Y 2 0 1 6 3 E D M 1 " = 2 0 ' G Z A G e o E n v i r o n m e n t a l , I n c . E n g i n e e r s a n d S c i e n t i s t s w w w . g z a . c o m P R O J E C T N O . D A T E : R E V I S I O N N O . D E S I G N E D B Y : P R O J M G R : D R A W N B Y : R E V I E W E D B Y : C H E C K E D B Y : S C A L E : P R E P A R E D B Y : P R E P A R E D F O R : R O B E R T S M E A D O W B R O O K C H A N N E L R E H A B I L I T A T I O N P R O J E C T N O R T H A M P T O N , M A S S A C H U S E T T S D R A W I N G G R A P H I C S C A L E 0 1 0 2 0 4 0 S C A L E I N F E E T T E M P O R A R Y A C C E S S & S T A G I N G A R E A P L A N N 1 7 2 0 2 9 . 0 0 M A T M A T T E J C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S J G D M A Y 2 0 1 6 4 E D M 1 " = 2 0 ' G Z A G e o E n v i r o n m e n t a l , I n c . E n g i n e e r s a n d S c i e n t i s t s w w w . g z a . c o m P R O J E C T N O . D A T E : R E V I S I O N N O . D E S I G N E D B Y : P R O J M G R : D R A W N B Y : R E V I E W E D B Y : C H E C K E D B Y : S C A L E : P R E P A R E D B Y : P R E P A R E D F O R : R O B E R T S M E A D O W B R O O K C H A N N E L R E H A B I L I T A T I O N P R O J E C T N O R T H A M P T O N , M A S S A C H U S E T T S D R A W I N G G R A P H I C S C A L E 0 1 0 2 0 4 0 S C A L E I N F E E T T E M P O R A R Y S E D I M E N T , E R O S I O N , A N D W A T E R C O N T R O L P L A N N 1 7 2 0 2 9 . 0 0 M A T M A T T E J C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S J G D M A Y 2 0 1 6 1 7 2 0 2 9 5 A S N O T E D G Z A G e o E n v i r o n m e n t a l , I n c . E n g i n e e r s a n d S c i e n t i s t s w w w . g z a . c o m P R O J E C T N O . D A T E : R E V I S I O N N O . D E S I G N E D B Y : P R O J M G R : D R A W N B Y : R E V I E W E D B Y : C H E C K E D B Y : S C A L E : P R E P A R E D B Y : P R E P A R E D F O R : B Y P A S S O F F L O W S A N D D E W A T E R I N G P L A N D R A W I N G E D M R O B E R T S M E A D O W B R O O K C H A N N E L R E H A B I L I T A T I O N P R O J E C T N O R T H A M P T O N , M A S S A C H U S E T T S M A T M A T T E J C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S J G D DEWATERING PLAN - ROBERTS MEADOW BROOK1. IntroductionThis Dewatering Plan consists of this narrative report and the attached drawins entitled “Roberts Meadow Brook Channel Rehabilitation P r o j e c t ” , b y G Z A , S h e e t s 1 - 9 of 9, dated March, 2017, which should be reviewed in concert with all permits issued for the Project. The Project Site includes the rea c h o f R o b e r t s M e a d o w B r o o k from the Lower Roberts Meadow Reservoir Dam to the Reservoir Road bridge, a distance of about 550 feet. This Dewatering Plan has b e e n p r e p a r e d f o r t h e C i t y o f Northampton to accompany its applications for wetland permitting. All work as shown on the above-referenced drawings shall rely on the s a m e c o m p o n e n t s f o r c o n t r o l of water and work area isolation, as discussed herein.MassDEP requires that a specific Dewatering Plan be prepared in accordance with MA DEP Western Region - Bureau of Resource P r o t e c t i o n - W e t l a n d s P r o g r a m document entitled ³0LQLPXP Information and Documentation for Dewatering 3ODQV´. This Dewatering Plan has been organized to f o l l o w t h e r e q u i r e d l i s t i n g o f information provided in that MassDEP document for ease of review.Following construction contract award and prior to any land-disturbing activities at the Site, the City of Northampton's contractor shall pr e p a r e a n d s u b m i t f o r a p p r o v a l the contractor's specific plans for implementing this Dewatering Plan to the satisfaction of the City and the permitting authorities.2. Regulatory “Time-of-Year” (TOY) RestrictionsAs of the date this Dewatering Plan was prepared, no TOY restrictions have been imposed for work at the Site by the U.S. Army Corps o f E n g i n e e r s , M a s s a c h u s e t t s Natural Heritage and Endangered Species Program, or Massachusetts Division of Fisheries and Wildlife.Start and end dates for work at the Site for elements of the Project shall be as per approvals for the various project elements and as per a n y s p e c i f i c s c h e d u l e s c i t e d i n the any of the Project's final permits.3. Cold-Water Fishery IdentificationThe following MA Department of Fish and Game “Coldwater Fishery Resources” website was reviewed:http://www.mass.gov/eea/agencies/dfg/dfw/wildlife-habitat-conservation/coldwater-fish-resources-map.htmlBased on this review, Roberts Meadow Brook is listed as a cold water fishery resource (SARIS_ID 3418900).4. Work Area Isolation and Bypass of Water Around the Areas of AlterationThe contractor shall provide a written Dewatering Plan that shall be consistent with these specifications and shall detail what means and m a t e r i a l s w i l l b e e m p l o y e d b y the contractor for Work Area Isolation and Bypass of Water Around the Areas of Alteration.During construction, active work areas shall be isolated from upstream and downstream wetlands and watercourses. Such isolation is fa c i l i t a t e d b y t h e r e l a t i v e l y s t e e p gradient (2.7%±) of the Project reach. Over the 400± feet of active stream channel work, the stream bottom drops almost 11 feet. The i m m e d i a t e l y - u p g r a d i e n t L o w e r Roberts Meadow Reservoir Dam shall function as a cofferdam retaining the Lower Reservoir, and the down-slope portions of the w o r k s h a l l b e p r o t e c t e d b y t h e elevational relief above downgradient waters supplemented by temporary cofferdams as may be required by the contractor's work (see n o t e c . , b e l o w ) . Normal flows within Roberts Meadow Brook shall be bypassed around the active work area by using the low-level drawdown mec h a n i s m o f t h e L o w e r R o b e r t s Meadow Reservoir. The intake for the low level outlet for the dam is approximately 45 feet upstream of the dam's spillway. The low le v e l o u t l e t c o n s i s t s o f a 1 2 - i n c h diameter ductile iron pipe, which ties into a manhole in the sandy beach on the upstream side of the dam near the middle of the right e m b a n k m e n t ( M u s a n t e B e a c h ) . Flow in the 12-inch diameter ductile iron pipe is regulated by a gate valve located immediately upstream of the manhole. From the m a n h o l e , f l o w i s c o n v e y e d v i a a 24-inch diameter outlet conduit, which discharges from a stone headwall to a discharge channel located downstream of the right s i d e o f t h e d a m , o n t h e e a s t (downgradient) side of Reservoir Road. The low-level outlet utilizes components installed after the 1955 flood and newer element s a d d e d i n t h e l a t e 1 9 8 0 s i n preparation for the opening of Musante Beach.The overall capacity of the low-level outlet works is controlled (and limited) by the 12-inch diameter pipe. The theoretical capacity of the 1 2 - i n c h l o w l e v e l o u t l e t r a n g e s from approximately 12 cfs, with the reservoir at normal pool elevation, to 15 cfs with the reservoir at the top of the dam. The capacity o f t h e l o w - l e v e l o u t l e t h a s b e e n judged insufficient for drawing down the reservoir in a reasonable period of time under reasonably-anticipated hydrologic conditions. N o t w i t h s t a n d i n g , t h e l o w - l e v e l outlet offers a unique opportunity for the bypass of clean baseflows around the active work areas, and the outlet's capacity can be i n c r e a s e d a t c r i t i c a l t i m e s b y supplemental pumping from the reservoir. The 12”-diameter outlet pipe discharges to the manhole in the sloped beach, where the pip e d i a m e t e r i n c r e a s e s t o 2 4 ” - - a four-fold increase in flow area as compared to the 12” outlet pipe. In times of need, the bypass capacity can be increased by supplemen t a l p u m p i n g f r o m t h e r e s e r v o i r and discharging directly to the opened manhole, combining the pumped flow with the flow coming from the 12” outlet pipe. In such e v e n t s , t h e b y p a s s c a p a c i t y i s limited by the downstream culvert passing under the private driveway prior to the flow joining back to Roberts Meadow Brook, im m e d i a t e l y d o w n s t r e a m o f t h e Reservoir Road bridge. Assuming a maximum allowable headwater of five feet at the upstream end of this culvert (the height o f t h e d r i v e w a y c r o s s i n g i s approximately seven feet), the ultimate bypass capacity is limited to about 35 cfs. Although it is likely impractical to pump across R e s e r v o i r R o a d , s u p p l e m e n t a l bypass pumps could be installed in the vicinity of the bath house, with the discharge hose(s) extending longitudinally down the brook ch a n n e l t o p o i n t s d o w n s t r e a m o f the active work areas. In all cases, the contractor shall adjust their operations such that the water level within the Lower Reservoir is n o t l o w e r e d m o r e t h a n t w o f e e t below the Mean Annual Low Water Level (top of overflow spillway at dam).A StreamStats (v3.0) evaluation of Roberts Meadow Brook at the Reservoir Road bridge reveals a statistical annual “D50” low flow of 1 0 . 8 c f s , a n d a n “ A u g u s t D 5 0 ” o f 3 . 4 c f s . T h e U S G S Wandle Method (Estimating Peak Discharges of Small Rural Streams in Massachusetts, S. Wandle, Jr., Open File Report 80-676 , U . S . G e o l o g i c a l S u r v e y ) p r e d i c t s a 2 - y e a r r e t u r n frequency storm peak flow of about 430 cfs, significantly higher than the bypass capacity. This level of flow is judged impractical to effe c t i v e l y b y p a s s . I n c o n s i d e r a t i o n t h a t a l l m a t e r i a l s t o be re-distributed or imported into areas below the MAHWL will consist of natural inert materials already in the channel or similar n a t u r a l l y - o c c u r r i n g m a t e r i a l s i m p o r t e d f r o m o f f - s i t e locations, inundation during periods of high flow is not anticipated to have unacceptable environmental impacts to either the work area or a r e a s d o w n s t r e a m . In cases where watershed flows in excess of the bypass capacity are anticipated, the work shall cease, all equipment and loose materia l s s h a l l b e r e m o v e d f r o m t h e a c t i v e w o r k a r e a s a n d to areas above the 100-year flood elevation, and the watershed flows shall be allowed to overtop the Lower Reservoir dam and flow thr o u g h t h e s e c u r e d w o r k a r e a s . F o l l o w i n g c e s s a t i o n of high flows, the bypass and work activities shall resume.Relative to the Bypass of Water Around the Area of Alteration, work within the Roberts Meadow Brook waterway shall meet the following s t a n d a r d s : a.Work below the MAHWL of Roberts Meadow Brook shall be timed to take place during low- or no-flow conditions, when the flow of t h e b r o o k c a n b e b y p a s s e d a r o u n d t h e a c t i v e w o r k area by utilization of the low-level bypass, in conjunction with additional bypass pumps. In addition to the capacity of the un-assist e d l o w - l e v e l o u t l e t w o r k s ( 1 2 - 1 5 c f s ) , t h e c o n t r a c t o r shall have on-hand, at the Site and in working order, a minimum bypass pumping capacity of at least 20 cfs (9,000 gpm; typica l l y p r o v i d e d b y t w o ( 2 ) 8 ” - d i a m e t e r d i e s e l - p o w e r e d centrifugal pumps). Thus, a combined bypass capacity of 35 cfs shall be realized. Low flow conditions are defined as flow withi n t h e R o b e r t s M e a d o w B r o o k s y s t e m a t R e s e r v o i r Road that are at or below the Contractor's actual bypass capacity, considering the combined total of the unassisted low-level o u t l e t w o r k s a n d a n y c o n t r a c t o r - s u p p l i e d b y p a s s pumping infrastructure.b.When bypass pumping is necessary or desired, the intake hose(s) shall be placed on a stable surface or floated to prevent sedi m e n t f r o m e n t e r i n g t h e h o s e . T h e b y p a s s d i s c h a r g e shall be placed on a nonerodible, energy dissipating surface prior to rejoining the stream flow and shall not cause erosion. Filterin g o f b y p a s s w a t e r s h a l l b e p e r f o r m e d i s t h e b y p a s s water has become sediment-laden as a result of the proposed construction activities.c.In the event that minor cofferdams may need to be employed, such cofferdams or other systems which would require the du m p i n g o f s o i l o r r o c k i n t o a r e a s b e l o w M A H W L a r e specifically excluded, with the exception that approved sand bags and “supersacks” may be allowed.5. Dewatering of the Work AreasThe contractor shall provide a written Dewatering Plan that shall be consistent with these specifications and shall detail what means and m a t e r i a l s w i l l b e e m p l o y e d b y t h e c o n t r a c t o r f o r t h e dewatering of the work areas and the removal of sediments from dewatering activities.The contractor shall dewater the active work area(s) to remove accumulated groundwater and surficial runoff. During dewatering of the a c t i v e w o r k a r e a s , a l l s e d i m e n t - l a d e n w a t e r s h a l l b e filtered to remove sediment. These drawings and associated permit applications have been prepared using Dirtbag® geotextile de-water i n g b a g s a s a p r e f e r r e d m e a n s t o r e m o v e s e d i m e n t from dewatering waters. Possible other options for sediment removal may include baffle systems, frac tanks, or other appropriate metho d s . Standing water within the active work areas shall be removed via pumping to the Dirtbag®, using flow rates in accordance with manufact u r e r ' s i n s t r u c t i o n s . O n c e t h e w o r k a r e a s h a v e b e e n initially dewatered, a low-level sump with washed crushed stone shall be installed as per the Drawings to allow for the use of a pump to m a i n t a i n a d r y w o r k a r e a d u r i n g t h e c o n s t r u c t i o n a n d channel rehabilitation process. At a minimum, the dewatering pump shall be a 2-inch trash (mud) pump or equivalent. Sufficient pumpin g c a p a c i t y s h a l l b e a v a i l a b l e o n s i t e 2 4 h o u r s a d a y , 7 days a week to maintain adequate dewatering rates. Flows from the dewatering pumps shall be conveyed via flexible hose (4-inch m a x . d i a m e t e r ) t o t h e D i r t b a g ® f o r t r e a t m e n t p r i o r t o discharge. The dewatering pumping rate shall not exceed the treatment rate of the Dirtbag®.Due to the size and nature of the work area, the dewatering sump shall be moved or additional sumps located along the work area as co n s t r u c t i o n p r o g r e s s e s a l o n g t h e s t r e a m c h a n n e l . A l l sumps shall be installed using the same technique and same discharge routing to a separate (or relocated) DirtBag® placed on an uplan d a r e a a d j a c e n t t o t h e w o r k a r e a . The Dirtbag® shall provide for sediment capture and velocity dissipation for dewatering dis-charges and allow filtered water to pass th r o u g h t h e g e o t e x t i l e m a t e r i a l , d i s c h a r g i n g f r o m t h e bag. The DirtBag® shall be placed within a basin constructed of a crushed stone and geotextile base and straw wattle walls to provide i n f i l t r a t i o n a n d a d d i t i o n a l f i l t e r i n g . A n o u t l e t t o t h e basin shall be constructed of a crushed stone overflow weir lined with jute netting. The jute netting shall continue along the ground sur f a c e , e x t e n d i n g b e y o n d t h e f o o t p r i n t o f t h e c r u s h e d stone out-let. This configuration shall also allow for the addition of powdered anionic flocculent and/or the use of FlocLogs®, in the e v e n t t h a t f i n e g r a i n e d s o i l s a r e e n c o u n t e r e d a n d additional sediment removal is required beyond that provided by the Dirtbag®. Water shall be directed to flow overland from the filter b a s i n o u t l e t , d i s c h a r g i n g d o w n g r a d i e n t i n a n u p l a n d area located adjacent to Roberts Meadow Brook or, in some cases, the upgradient reservoir.Discharge water will be considered clean only if it does not result in a visually-identifiable degradation of water clarity.Areas from the toe to the top of the side slopes shall be temporarily stabilized during construction to reduce the potential for erosion and t h e t r a n s p o r t o f s e d i m e n t s i n t o t h e a r e a s t o b e dewatered. All areas disturbed due to construction activities shall be restored to proposed conditions and fully stabilized prior to acceptin g f l o w s . D E W A T E R I N G P L A N - R O B E R T S M E A D O W B R O O K ( c o n t . ) 6 . M a n a g e m e n t o f A q u a t i c O r g a n i s m s A q u a t i c o r g a n i s m s ( s u c h a s v e r t e b r a t e s , c r a y f i s h , a n d f r e s h w a t e r m u s s e l s ) s t r a n d e d a s a r e s u l t o f t h e d e w a t e r i n g p r o c e s s o r e x c a v a t i o n i n w o r k a r e a s s h a l l b e s a l v a g e d b y t h e C i t y o f N o r t h a m p t o n ' s q u a l i f i e d E n v i r o n m e n t a l C o n s u l t a n t a n d p r o m p t l y r e s t o r e d t o t h e a p p r o p r i a t e h a b i t a t ( s t r e a m c h a n n e l , w e t l a n d , o r p o n d ) o u t s i d e o f t h e i s o l a t e d w o r k a r e a s . A v i s u a l r e v i e w o f t h e d e w a t e r e d a r e a s s h a l l b e c o n d u c t e d d u r i n g a n d i m m e d i a t e l y a f t e r d e w a t e r i n g i s c o m p l e t e d , a n d a n y s e s s i l e a q u a t i c o r g a n i s m s e n c o u n t e r e d s h a l l b e s a l v a g e d a s p e r t h e m e t h o d s t a t e d a b o v e . S i m i l a r l y , o r g a n i s m s i d e n t i f i e d d u r i n g t h e e x c a v a t i o n p r o c e s s s h a l l b e s a l v a g e d . 7 . S t a b i l i z a t i o n T h e s y s t e m s f o r B y p a s s o f W a t e r A r o u n d t h e A r e a s o f A l t e r a t i o n a n d D e w a t e r i n g o f t h e W o r k A r e a s s h a l l r e m a i n i n p l a c e a n d c o n t i n u e t o o p e r a t e a s n e e d e d t o p r e v e n t s e d i m e n t - l a d e n w a t e r f r o m d i s c h a r g i n g t o t h e L o w e r R o b e r t s M e a d o w R e s e r v o i r o r R o b e r t s M e a d o w B r o o k u n t i l w o r k i s c o m p l e t e d . S u m p s s h a l l b e r e m o v e d a n d a l l a r e a s r e s t o r e d u s i n g t h e m a t e r i a l t a k e n f r o m t h e w o r k a r e a s e t b a c k i n p l a c e . B e f o r e t h e b y p a s s s y s t e m s a r e r e m o v e d , t h e C i t y o f N o r t h a m p t o n ' s E n g i n e e r a n d q u a l i f i e d E n v i r o n m e n t a l C o n s u l t a n t s h a l l r e v i e w t h e a r e a t o v e r i f y t h a t t h e s u b s t r a t e i s i n a s t a b l e c o n d i t i o n p r i o r t o t h e r e e s t a b l i s h m e n t o f f l o w w i t h i n i t . T h e c o n t r a c t o r s h a l l a d j u s t t h e w o r k t o s a t i s f y i s s u e s a n d c o n c e r n s i d e n t i f i e d b y t h e C i t y o r i t s c o n s u l t a n t s . N G R A P H I C S C A L E 0 2 0 4 0 8 0 S C A L E I N F E E T M A Y 2 0 1 6 1 7 2 0 2 9 6 A S N O T E D G Z A G e o E n v i r o n m e n t a l , I n c . E n g i n e e r s a n d S c i e n t i s t s w w w . g z a . c o m P R O J E C T N O . D A T E : R E V I S I O N N O . D E S I G N E D B Y : P R O J M G R : D R A W N B Y : R E V I E W E D B Y : C H E C K E D B Y : S C A L E : P R E P A R E D B Y : P R E P A R E D F O R : R O B E R T S M E A D O W B R O O K C H A N N E L R E H A B I L I T A T I O N P R O J E C T N O R T H A M P T O N , M A S S A C H U S E T T S S E D I M E N T , E R O S I O N , A N D W A T E R C O N T R O L N O T E S A N D D E T A I L S D R A W I N G ( 1 2 " T Y P I C A L ) BEST MANAGEMENT PRACTICES:INSPECTION AND MAINTENANCE·SEDIMENT AND EROSION CONTROLS AND BMPS SHALL BE INSTALLED PRIOR TO COMMENCINGCONSTRUCTION AT THE SITE. NO WORK WHICH SHALL DISTURB THE SITE OR CREATE THEPOTENTIAL FOR SEDIMENT RELEASE SHALL COMMENCE UNTIL THE SEDIMENT AND EROSIONCONTROLS HAVE BEEN INSPECTED AND APPROVED BY THE OWNER, ENGINEER, AND REGULATORYAGENCIES INCLUDING THE NORTHAMPTON CONSERVATION COMMISSION. ALL CONTROLS ANDBMPS SHALL BE SUBJECT TO AN INITIAL INSPECTION BY THE OWNER, HIS REPRESENTATIVE, ANDREGULATORY AGENCIES INCLUDING THE NORTHAMPTON CONSERVATION COMMISSION ATANYTIME THEREAFTER.·PERIODIC INSPECTION, MAINTENANCE, AND CLEANING OF TEMPORARY EROSION OF SEDIMENTCONTROL MEASURES AND BEST MANAGEMENT PRACTICES (BMPS) ARE REQUIRED AND SHALL BEPERFORMED BY THE CONTRACTOR. ALL CONTROLS AND BMPS SHALL BE INSPECTED EVERY 7 DAYSAND WITHIN 24 HOURS OF RAINFALL EVENTS OF 0.5 INCHES OR GREATER. ROUTINE INSPECTIONAND MAINTENANCE WILL REDUCE THE CHANCE OF POLLUTING STORMWATER BY FINDING ANDCORRECTING PROBLEMS BEFORE THE NEXT RAIN EVENT. A SITE MAINTENANCE LOG SHALL BEPREPARED AND UPDATED AS PER THE SWPPP.·THE FOCUS OF THE PERIODIC CONTRACTOR LED INSPECTIONS SHALL BE TO DETERMINE: 1)WHETHER OR NOT THE MEASURE WAS INSTALLED / PERFORMED CORRECTLY; 2) WHETHER ORNOT THERE HAS BEEN ANY DAMAGE TO THE MEASURE SINCE IT WAS INSTALLED OR PERFORMED;AND 3) WHAT SHOULD BE DONE TO CORRECT ANY PROBLEMS WITH THE MEASURE. EACHMEASURE IS TO BE OBSERVED TO DETERMINE IF IT IS STILL EFFECTIVE. IN SOME CASES, SPECIFICMEASUREMENTS MAY BE TAKEN TO DETERMINE IF MAINTENANCE OF THE MEASURES ISREQUIRED.SITE MANAGER·PRIOR TO CONSTRUCTION, A SITE MANAGER SHALL BE DESIGNATED BY THE CONTRACTOR TO BERESPONSIBLE FOR INSTALLATION, MONITORING, INSPECTION, AND CORRECTION OF EROSIONAND SEDIMENT CONTROL MEASURES.REPORTING AND RECORD KEEPING·IN ADDITION TO THE AFOREMENTIONED INSPECTION AND MAINTENANCE PROCEDURES, THECONTRACTOR SHALL KEEP A RECORD OF THE FOLLOWING INFORMATION:OTHE DATES WHEN MAJOR GRADING ACTIVITIES OCCUR IN A PARTICULAR AREA;OTHE DATES WHEN CONSTRUCTION ACTIVITIES CEASE IN AN AREA, TEMPORARILY ORPERMANENTLY;OTHE DATES WHEN AN AREA IS STABILIZED, TEMPORARILY OR PERMANENTLY;OA COPY OF THE STORMWATER POLLUTION PREVENTION PLAN (SWPPP) AND ALL REPORTSGENERATED DURING CONSTRUCTION ACTIVITIES ARE TO BE RETAINED AS REQUIRED BYREGULATION.STABILIZEDCONSTRUCTION ENTRANCE·TO REDUCE THE TRACKING OF SEDIMENT FROM THE CONSTRUCTION SITE ONTO OTHER AREAS OFTHE PROPERTY AND/OR PUBLIC ROADS, AS WELL AS THE PRODUCTION OF AIRBORNE DUST, ASTABILIZED CONSTRUCTION ENTRANCE IS TO BE ESTABLISHED AS SHOWN AND AT ANYADDITIONAL AUTHORIZED CONSTRUCTION STAGING AREA. THE ENTRANCE IS TO CONSIST OF AMINIMUM 6-INCH THICK PAD OF CRUSHED STONE UNDERLAIN WITH FILTER FABRIC AND SHALLBE CONSTRUCTED ON LEVEL GROUND.·ADDITIONAL TEMPORARY CONSTRUCTION SITE ENTRANCES MAY BE ADDED AROUND THE SITEPER THE CONTRACTOR'S APPROVED WORK PLAN.SITE CLEARING·PRIOR TO ANY SITE CLEARING ACTIVITIES, SEDIMENT CONTROL BARRIERS SHALL BE PLACEDDOWNSLOPE (STRAW WATTLE/ SILT FENCE BARRIERS) ALONG THE OUTER LIMIT OF DISTURBANCE.CLEARING IS TO BE LIMITED TO THOSE AREAS OF PROPOSED WORK. DISTURBED AREAS ARE TO BEKEPT TO A MINIMUM. NO TREE WITH A BREAST HEIGHT DIAMETER OF GREATER THAN 6 INCHESSHALL BE CLEARED FROM STAGING AREAS WITHOUT PRIOR APPROVAL FROM THE OWNER. DUST CONTROL·STANDARD DUST CONTROL MEASURES, INCLUDING THE USE OF WATER TRUCKS AND MISTINGSHALL BE USED AS NECESSARY. CALCIUM CHLORIDE SHALL BE USED ONLY WITH PRIOR APPROVALFROM THE OWNER AND AS ALLOWED BY PROJECT PERMITS.STAGING AREAS·THE CONTRACTOR MAY ESTABLISH LAYDOWN AND STAGING AREAS IN WHICH TO STOREEQUIPMENT AND MATERIALS IN AREAS IDENTIFIED BY THE OWNER. LOCATION OF ADDITIONALAREAS, IF NEEDED, SHALL BE COORDINATED WITH AND SHALL BE SUBJECT TO APPROVAL BY THEOWNER.STOCKPILED MATERIALS·STOCKPILES OF SOIL CREATED DURING CONSTRUCTION ACTIVITIES ARE SHALL BE SURROUNDEDWITH COMPOST SOCKS, STRAW WATTLES, AND/OR SILT FENCE WHERE POSSIBLE. OTHERALTERNATIVES UTILIZED MAY INCLUDE GRAVEL FILTER BERMS OR SIMILAR MEASURES LAIDAROUND THE PERIMETER OF THE STOCKPILE. STOCKPILES OF ERODIBLE MATERIAL SHALL BECOVERED PRIOR TO INCLEMENT WEATHER WITH A MINIMUM OF 20 MIL POLYETHYLENESHEETING.EQUIPMENT FUELING·EQUIPMENT FUELING AND OTHER ACTIVITIES INVOLVING PETROLEUM, OIL, OR OTHERPOTENTIALLY HAZARDOUS SUBSTANCES SHALL BE PERFORMED AT PRE-APPROVED, DESIGNATEDAREAS WITH APPROPRIATE SPILL PREVENTION AND CONTROL MEASURES. THIS AREA SHALL BELOCATED ON AN ASPHALT PAVED SURFACE, AWAY FROM CATCH BASINS AND OTHER DRAINAGESTRUCTURES. PORTABLE SECONDARY CONTAINMENT IS TO BE USED, AND SORBENT MATERIALSARE TO BE PLACED AROUND THE PERIMETER OF THE FUELING AREA. FUELING WITHIN THESTATUTORY BUFFER ZONE (100 FEET FROM WETLANDS OR BANK) WILL GENERALLY NOT BEALLOWED.TEMPORARY STABILIZATION·WHEN NECESSARY, TEMPORARY SLOPE PROTECTION SHALL BE PROVI D E D B Y I N S T A L L I N G S T R A W WATTLE / SILT FENCE BARRIERS AT THE TOE OF FILLS OR CUT S L O P E S . I F A D D I T I O N A L STABILIZATION IS NEEDED, THEN THE CONTRACTOR SHALL INSTALL M A T T I N G , S U C H A S S T R A W , JUTE, WOOD FIBER, OR BIO OR PHOTO-DEGRADABLE MESH AT NO A D D I T I O N A L C O S T T O T H E OWNER. CLEARING, GRUBBING AND REMOVAL OF LOAM SHALL ON L Y O C C U R I N A R E A S T H A T WILL BE GRADED AND PROTECTED TO MITIGATE EROSION AND TRAN S P O R T O F S E D I M E N T I N T O THE ROBERTS MEADOW BROOK.·IN THE EVENT THAT DISTURBED AREAS AT THE SITE ARE TO BE LEFT UN- W O R K E D F O R M O R E T H A N TWO WEEKS, THE AREAS SHALL BE MULCHED WITH STRAW AT A RATE O F 1 0 0 L B S . P E R 1 , 0 0 0 S . F . TO HELP CONTROL EROSION. TWO INCHES OF WOOD CHIP MULC H M A Y A L S O B E U S E D A S TEMPORARY COVER.·IN THE EVENT THAT DISTURBED AREAS AT THE SITE ARE TO BE LEFT UN- W O R K E D F O R M O R E T H A N ONE MONTH, THE AREAS SHALL BE TOPSOILED AND SEEDED AS PER T H E S P E C I F I C A T I O N S A N D A T NO ADDITIONAL COST TO THE OWNER.·LEAVE THE SURFACE OF ALL EXCAVATIONS AND FILLS IN A FIRM AND S T A B L E C O N D I T I O N A T T H E END OF EACH DAY. ROLL OR OTHERWISE TREAT THE SURFACE AS NEED E D . SITE RESTORATION·STABILIZATION OF DISTURBED AREAS OR NEW SOIL FILLS SHALL BE I M P L E M E N T E D W I T H I N 1 4 DAYS AFTER GRADING OR CONSTRUCTION ACTIVITIES HAVE TEMPO R A R I L Y O R P E R M A N E N T L Y CEASED. APPROPRIATE VEGETATIVE SOIL STABILIZATION IS TO BE US E D T O M I N I M I Z E E R O S I O N . TEMPORARY AND PERMANENT VEGETATIVE COVER IS TO BE ESTABLIS H E D I N A C C O R D A N C E W I T H THE PROJECT PLANS AND SPECIFICATIONS, USING HYDRO-SEEDING, B R O A D C A S T I N G , O R O T H E R APPROVED TECHNIQUES.·THE CONTRACTOR SHALL BE RESPONSIBLE FOR RESTORATION OF P R E V I O U S L Y V E G E T A T E D UPLAND AREAS DISTURBED BY CONSTRUCTION ACTIVITIES. RESTOR A T I O N O F U P L A N D A R E A S SHALL CONSIST OF REPLACEMENT OF TOPSOIL OR PLACEMENT OF IM P O R T E D L O A M A S N E E D E D SUCH THAT A MINIMUM OF 6 INCHES OF SUITABLE MATERIAL IS PRES E N T A N D A P P R O P R I A T E L Y , LIMED, FERTILIZED, GRADED, AND SCARIFIED.·WHERE NOT OTHERWISE SPECIFIED, DISTURBED UPLAND AREAS BE Y O N D T H E 1 0 0 ' W E T L A N D BUFFER ZONE SHALL THEN BE SEEDED WITH AN APPROVED SEED MIX A T A R A T E O F 2 P O U N D S O F LIVE SEED PER 1,000 S.F. SEEDING RATE SHALL BE DOUBLED FOR DOR M A N T S E E D I N G . S E E D M I X FOR AREAS BEYOND THE 100' WETLAND BUFFER ZONE SHALL BE AS F O L L O W S O R A S A P P R O V E D BY THE ENGINEER:CREEPING RED FESCUE50%KENTUCKY 3125%DOMESTIC RYE10%RED TOP5%LADINO CLOVER5%·WHERE NOT OTHERWISE SPECIFIED, DISTURBED UPLAND AREAS WI T H I N T H E 1 0 0 ' W E T L A N D BUFFER ZONE SHALL THEN BE SEEDED WITH AN APPROVED SEED MIX A T A R A T E O F 1 P O U N D O F LIVE SEED PER 1,000 S.F. SEEDING RATE SHALL BE DOUBLED FOR DOR M A N T S E E D I N G . S E E D M I X FOR AREAS WITHIN THE 100' WETLAND BUFFER ZONE SHALL BE AS FOL L O W S O R A S A P P R O V E D B Y THE ENGINEER:THE NEW ENGLAND EROSION CONTROL/RESTORATION MIX (MOIST SI T E S ) T Y P I C A L L Y C O N T A I N S THE FOLLOWING:SWITCHGRASS (PANICUM VIRGATUM),VIRGINIA WILD RYE (ELYMUS VIRGINICUS),CREEPING RED FESCUE (FESTUCA RUBRA),FOX SEDGE (CAREX VULPINOIDEA),CREEPING BENTGRASS (AGROSTIS STOLONIFERA),SOFT RUSH (JUNCUS EFFUSUS),NEW ENGLAND ASTER (ASTER NOVAE-ANGLIAE),GRASS-LEAVED GOLDENROD (EUTHAMIA GRAMINIFOLIA),NODDING BUR MARIGOLD (BIDENS CERNUA),GREEN BULRUSH (SCIRPUS ATROVIRENS),JOE-PYE WEED (EUPATORIUM MACULATUM),BONESET (EUPATORIUM PERFOLIATUM),BLUE VERVAIN (VERBENA HASTATA).·RESTORED AREAS SHALL BE ROLLED AND THEN APPROPRIATELY MULC H E D W I T H S T R A W , W O O D CHIPS OR OTHER APPROVED WEED-FREE MATERIAL. BIO OR PHO T O - D E G R A D A B L E E R O S I O N CONTROL FABRIC IS ALSO ACCEPTABLE FOR POST-RESTORATION S T A B I L I Z A T I O N . O N F L A T SURFACES AND ON SLOPES OF 3:1 OR FLATTER, MULCH OR EROSION C O N T R O L M A T T I N G S H A L L TO BE USED AFTER PERMANENT SEEDING TO PROTECT SOIL FROM TH E I M P A C T O F F A L L I N G R A I N AND TO INCREASE THE CAPACITY OF THE SOIL TO ABSORB WATE R . F O R S T E E P E R S L O P E S , EROSION CONTROL MATTING SHALL BE USED AS DESCRIBED IN SECTIO N 0 2 9 3 0 OF THE CONTRACT DOCUMENTS.·FINAL STABILIZATION SHALL BE CONSIDERED COMPLETE WHEN ALL S O I L - D I S T U R B I N G A C T I V I T I E S HAVE BEEN COMPETED AND A UNIFORM, PERENNIAL VEGETATIVE C O V E R W I T H A D E N S I T Y O F EIGHTY PERCENT HAS BEEN ESTABLISHED OR EQUIVALENT STABILIZA T I O N M E A S U R E S ( S U C H A S THE USE OF MULCHES OR EROSION CONTROL MATTING) HAVE BEEN E M P L O Y E D O N A L L U N P A V E D AREAS AND AREAS NOT COVERED BY PERMANENT STRUCTURES. A C H I E V E M E N T O F F I N A L STABILIZATION SHALL BE DETERMINED BY THE CITY.·THE CONTRACTOR SHALL BE RESPONSIBLE FOR MAINTENANCE OF A L L V E G E T A T E D S U R F A C E S , INCLUDING WATERING, FERTILIZING, AND RE-SEEDING UNTIL ESTABLI S H M E N T C O N D I T I O N S A R E MET AND UNTIL THE END OF THE CONTRACTUAL MAINTENANCE PERIO D . WATER CONTROL NOTES:1.TEMPORARY WATER CONTROL BY THE CONTRACTOR SHALL BE P E R F O R M E D I N A C C O R D A N C E W I T H T H E S E D R A W I N G S A N D S E C T I O N 0 1 5 6 5 O F T H E SPECIFICATIONS.2.THE CONTRACTOR SHALL BE RESPONSIBLE FOR ALL TEMPORARY C O N T R O L O F S U R F A C E W A T E R S A N D G R O U N D W A T E R N E C E S S A R Y T O E X E C U T E A N D COMPLETE THE WORK OF THE CONTRACT SUBJECT TO THE RESTRIC T I O N S C O N T A I N E D I N T H E C O N T R A C T D O C U M E N T S A N D P R O J E C T P E R M I T S . C O N T R O L S SHOWN IN THE CONTRACT DRAWINGS AND MENTIONED IN THE T E C H N I C A L S P E C I F I C A T I O N S S H A L L B E C O N S I D E R E D M I N I M U M R E Q U I R E M E N T S . T H E CONTRACTOR SHALL EMPLOY WHATEVER SUPPLEMENTARY MEASU R E S N E C E S S A R Y T O P R O T E C T T H E S I T E A N D T H E W O R K S , A T N O A D D I T I O N A L C O S T T O THE OWNER.3.ALL TEMPORARY WATER CONTROL MEASURES SHALL BE IMPLE M E N T E D I N C O N J U N C T I O N W I T H A P P R O P R I A T E S E D I M E N T A N D E R O S I O N C O N T R O L MEASURES SO AS TO MITIGATE TO THE GREATEST EXTENT POSSIBLE R E L E A S E O F S E D I M E N T I N T O W A T E R B O D I E S A N D P O T E N T I A L E R O S I O N O F S O I L . 4.ACTIVE DRAWDOWN, PUMPING, OR DEWATERING OF LOWER ROBE R T S M E A D O W R E S E R V O I R B E L O W E L . 3 6 9 ± ( N G V D 2 9 ) S H A L L N O T B E A L L O W E D . 5.THE RESERVOIR WATER LEVELS AND STREAM FLOWS TYPICALLY FLU C T U A T E I N R E S P O N S E T O C L I M A T E C O N D I T I O N S . 6.ANY TEMPORARY PUMPS UTILIZED AT THE SITE SHALL BE PROPERLY B A F F L E D A G A I N S T E X C E S S I V E N O I S E . P U M P S O R G E N E R A T O R S W H I C H U T I L I Z E L I Q U I D FUEL SHALL BE PLACED WITHIN AN IMPERMEABLE SECONDARY CO N T A I N M E N T A R E A W I T H S U F F I C I E N T C A P A C I T Y T O C O N T A I N T H E F U L L V O L U M E O F T H E FUEL TANK.7.PUMP OR SIPHON INTAKES SHALL BE PLACED SUCH THAT SEDIMENT A N D D E B R I S E N T R A I N M E N T I S M I N I M I Z E D . 8.WATER PUMPED FROM EXCAVATIONS SHALL BE PASSED THROU G H A S E D I M E N T A T I O N T A N K O R O T H E R S U C H B E S T M A N A G E M E N T P R A C T I C E ( B M P ) FEATURE PRIOR TO BEING DISCHARGED BACK TO A SURFACE WATER B O D Y . 9.FOLLOWING TREATMENT IN AN APPROPRIATE BMP, WATER PUMP E D F R O M E X C A V A T I O N S S H O U L D G E N E R A L L Y B E D I S C H A R G E D S U C H T H A T I T E N T E R S THE BROOK, RATHER THAN BACK INTO THE WORK AREA.10.THE DISCHARGE AREA FOR THE PUMP OR SIPHON OUTLET SHALL BE P R O P E R L Y P R O T E C T E D T O P R E V E N T E R O S I O N B Y H I G H V E L O C I T Y F L O W . 11.DISCHARGE FLOW VELOCITY FROM PUMPS OR SIPHONS OVER UN P R O T E C T E D , V E G E T A T E D G R O U N D S H A L L N O T E X C E E D A M A X I M U M O F 1 F O O T P E R SECOND. DISCHARGE FLOW VELOCITY FROM PUMPS OR SIPHO N S W I T H I N T H E U N P R O T E C T E D N A T U R A L B R O O K C H A N N E L S H A L L N O T E X C E E D A MAXIMUM 3 FEET PER SECOND. IN THE EVENT EROSION RESULTS F R O M V E L O C I T I E S O F T H E S E M A G N I T U D E S , T H E C O N T R A C T O R S H A L L T A K E S T E P S T O MITIGATE THE EROSION OR SHALL REDUCE DISCHARGE FLOW VELOC I T Y . 12.THE CONTRACTOR MAY ELECT TO INSTALL A TEMPORARY COFFE R D A M D U R I N G C O N S T R U C T I O N O F T H E P R O P O S E D C H A N N E L I M P R O V E M E N T S . P E R SECTION 01565, THE CONTRACTOR IS SOLELY RESPONSIBLE FOR T H E D E S I G N , I N S T A L L A T I O N , M A I N T E N A N C E , A N D R E M O V A L O F T H E W A T E R C O N T R O L SYSTEM. THE CONTRACTOR'S WATER CONTROL METHODS SHALL I N C L U D E D P R O V I S I O N S F O R E M E R G E N C Y E V A C U A T I O N O F T H E W O R K A R E A I N T H E EVENT OF SIGNIFICANT FLOODING. THE TEMPORARY COFFERDAM M A Y B E C O N S T R U C T E D O F S A N D B A G S , E I T H E R S T A N D A R D S I Z E O R L A R G E S I Z E “ S U P E R SACKS”, A STEEL FRAME, CONCRETE BLOCKS, CONCRETE JERS E Y B A R R I E R S , O R O T H E R S I M I L A R S T R U C T U R A L E L E M E N T S C O M B I N E D W I T H A N IMPERMEABLE MEMBRANE OR FACING. THE ALIGNMENT OF THE C O F F E R D A M S H A L L B E D E T E R M I N E D B Y T H E C O N T R A C T O R ; H O W E V E R , T H E C O F F E R D A M SHALL NOT EXTEND BEYOND THE LIMIT OF WORK AS SHOWN O N T H E P L A N S . T H E A C T U A L A L I G N M E N T O F T H E C O F F E R D A M M A Y B E V A R I E D T O ACCOMMODATE ACTUAL CONDITIONS. THE CONTRACTOR IS RESP O N S I B L E F O R I N V E S T I G A T I N G A N D V E R I F Y I N G S T R E A M B O T T O M C O N D I T I O N S P R I O R T O SELECTION OF COFFERDAM TYPE AND INSTALLATION.13.SEE ALSO DRAWING NO. 5. A N T I C I P A T E D C O N S T R U C T I O N S E Q U E N C E : T H E I N T E N T O F T H I S A N T I C I P A T E D C O N S T R U C T I O N S E Q U E N C E I S T O P R O V I D E G U I D A N C E T O T H E C O N T R A C T O R T O W A R D S M E E T I N G T H E T E R M S A N D C O N D I T I O N S O F E N V I R O N M E N T A L P R O T E C T I O N P E R M I T S A N D B E S T M A N A G E M E N T P R A C T I C E S A N D T H E R E F O R E I S N O T C O N S I D E R E D C O M P L E T E . C E R T A I N A S P E C T S O F T H I S A N T I C I P A T E D C O N S T R U C T I O N S E Q U E N C E M A Y B E A L T E R E D B Y T H E C O N T R A C T O R W I T H A P P R O V A L F R O M T H E O W N E R O R E N G I N E E R , E X C E P T A S R E Q U I R E D B Y P E R M I T C O N D I T I O N S A N D S P E C I F I C R E Q U I R E M E N T S O F T H E C O N T R A C T D O C U M E N T S . 1 . D E V E L O P P R O J E C T S C H E D U L E , A P P L Y F O R N E C E S S A R Y P E R M I T S , A N D B E G I N P R E P A R A T I O N O F S U B M I T T A L S P R I O R T O S T A R T O F W O R K A T S I T E A F T E R _ _ _ _ _ _ _ _ _ , 2 0 1 _ . 2 . M O B I L I Z E A L L N E C E S S A R Y E Q U I P M E N T , P E R S O N N E L , A N D M A T E R I A L T O T H E S I T E A N D D E P L O Y T E M P O R A R Y S E D I M E N T A N D E R O S I O N C O N T R O L M E A S U R E S , I N C L U D I N G P E R I M E T E R S T R A W W A T T L E / S I L T F E N C E B A R R I E R S , C O M P O S T S O C K S , A N D O T H E R B M P S . N O T I F Y T H E O W N E R , E N G I N E E R , A N D N O R T H A M P T O N C O N S E R V A T I O N C O M M I S S I O N . S C H E D U L E A N D C O N D U C T S I T E W A L K T O I N S P E C T S E D I M E N T A N D E R O S I O N C O N T R O L M E A S U R E S . 3 . M O D I F Y S E D I M E N T A N D E R O S I O N C O N T R O L M E A S U R E S A S R E Q U I R E D . W O R K M A Y P R O C E E D O N C E A P P R O V A L H A S B E E N P R O V I D E D B Y O W N E R , E N G I N E E R , A N D N O R T H A M P T O N C O N S E R V A T I O N C O M M I S S I O N . 4 . P R O V I D E A N D M A I N T A I N T R A F F I C C O N T R O L F O R T H E D U R A T I O N O F T H E P R O J E C T , I N C L U D I N G B A R R I E R S , G A T E S , F E N C I N G , S I G N A G E , A N D P U B L I C N O T I F I C A T I O N S . P L A C E T E M P O R A R Y S I G N A G E A R O U N D W O R K A R E A . 5 . C L E A R A N D G R U B S T A G I N G A R E A S , A N D P R O V I D E C O N S T R U C T I O N A C C E S S T O T H E C H A N N E L . P R O V I D E T E M P O R A R Y F A C I L I T I E S A S D E S C R I B E D I N T H E C O N T R A C T D O C U M E N T S . 6 . R E - L O C A T E / D I V E R T S T R E A M C H A N N E L T H R O U G H W O R K A R E A A S S H O W N O N T H E C O N T R A C T D R A W I N G S . R E M O V E D E B R I S A N D B O U L D E R S F R O M D O W N S T R E A M O F L O W E R R O B E R T S M E A D O W R E S E R V O I R D A M S P I L L W A Y . 7 . D E S I G N A N D C O N S T R U C T T E M P O R A R Y C O F F E R D A M S A N D P R O V I D E A N D M A I N T A I N T E M P O R A R Y W A T E R C O N T R O L S A S N E C E S S A R Y T O C O N D U C T T H E W O R K O F T H E P R O J E C T . T E M P O R A R Y C O F F E R D A M S H A L L B E D E S I G N E D B Y T H E C O N T R A C T O R A S P E R T H E C O N T R A C T D R A W I N G S A N D S P E C I F I C A T I O N S . O V E R A L L W A T E R C O N T R O L S H A L L B E C O N S I S T E N T W I T H P R O J E C T P E R M I T S A N D T O A L L O W T H E W O R K T O B E E X E C U T E D W I T H O U T I N T E R F E R E N C E F R O M S U R F A C E W A T E R A N D / O R G R O U N D W A T E R . T H E C O N T R A C T O R , I N C O N S U L T A T I O N W I T H T H E O W N E R A N D I N C O M P L I A N C E W I T H T H E E N V I R O N M E N T A L P E R M I T S , S H A L L M A N I P U L A T E T H E L E V E L S O F M I D D L E R O B E R T S M E A D O W R E S E R V O I R I N O R D E R T O M I N I M I Z E F L O W S T H R O U G H T H E W O R K A R E A . 8 . R E P A I R E R O D E D A R E A S O F S L O P E O N S O U T H E R L Y B A N K A S S H O W N O N T H E C O N T R A C T D R A W I N G S . 9 . C L E A R , G R U B , A N D S T R I P P R O P O S E D W O R K A R E A A L O N G N O R T H E R L Y B A N K O F B R O O K . 1 0 . R E M O V E E X I S T I N G S T O N E M A S O N R Y W A L L N E A R L E F T ( N O R T H E R L Y ) T R A I N I N G W A L L O F L O W E R R O B E R T S M E A D O W R E S E R V O I R D A M S P I L L W A Y . 1 1 . E X C A V A T E N O R T H E R L Y B A N K T O T H E L I N E S A N D G R A D E S S H O W N O N T H E C O N T R A C T D R A W I N G S . I N S T A L L R I P R A P E R O S I O N P R O T E C T I O N . 1 2 . G R A D E S L O P E A B O V E R I P R A P T O L I N E S A N D G R A D E S S H O W N O N C O N T R A C T D R A W I N G S . 1 3 . R E M O V E R I P R A P A C C E S S R A M P A N D R E S T O R E V E G E T A T I O N O N T H E B A N K S O F T H E S T R E A M C H A N N E L D O W N S T R E A M O F T H E S P I L L W A Y T O M A T C H E X I S T I N G C O N D I T I O N S . 1 4 . L O A M A N D S E E D R E W O R K E D A R E A S A S N O T E D O N T H E C O N T R A C T D O C U M E N T S . R E S T O R E A L L D I S T U R B E D A R E A S ; C O V E R O R M U L C H N E W L Y S E E D E D A R E A S . 1 5 . M A K E A L L M I S C E L L A N E O U S S I T E R E S T O R A T I O N S T O S T A G I N G A R E A S , F E N C I N G , U T I L I T I E S , P A V E M E N T , O R O T H E R F A C I L I T I E S C A U S E D A S A R E S U L T O F T H E W O R K A N D / O R M O B I L I Z A T I O N / D E M O B I L I Z A T I O N . 1 6 . D E M O B I L I Z E F R O M T H E J O B S I T E B Y _ _ _ _ _ _ _ _ _ , _ _ _ _ . R E M O V E A L L T E M P O R A R Y S T R U C T U R E S , T R A S H , D E B R I S , A N D O T H E R M A T E R I A L F R O M T H E S I T E . R E M O V E T E M P O R A R Y C O N T R O L S A N D S I G N A G E . R E M O V E T E M P O R A R Y S E D I M E N T A N D E R O S I O N C O N T R O L S W H E R E A P P R O P R I A T E . N O T I F Y O W N E R , E N G I N E E R , A N D N O R T H A M P T O N C O N S E R V A T I O N C O M M I S S I O N O F F I N A L S T A B I L I Z A T I O N . S C H E D U L E A N D C O N D U C T S I T E W A L K T O I N S P E C T S I T E . 1 7 . P R O V I D E O N - G O I N G M A I N T E N A N C E A N D M O N I T O R I N G O F N E W L Y V E G E T A T E D A N D R E S T O R E D A R E A S A S P E R T H E C O N T R A C T D O C U M E N T S . GENERAL SEDIMENT AND EROSION CONTROL NOTES:1.TEMPORARY SEDIMENT AND EROSION CONTROL BY THE CONTRACTOR SHALL BE PERFORMED INACCORDANCE WITH SECTION 01560 OF THE SPECIFICATIONS AND THE APPROVEDCONTRACTOR-PREPARED STORMWATER POLLUTION PREVENTION PLAN (SWPPP). A COPY OF THEAPPROVED SWPPP, SIGNED BY ALL RESPONSIBLE PARTIES, SHALL BE KEPT ON SITE AT ALL TIMES. ALLWORK SHALL BE PERFORMED IN ACCORDANCE WITH THE SWPPP.2.THE CONTRACTOR SHALL BE RESPONSIBLE FOR IMPLEMENTING ALL TEMPORARY SEDIMENT ANDEROSION CONTROL MEASURES NECESSARY TO EXECUTE AND COMPLETE THE WORK OF THE CONTRACT,IN COMPLIANCE WITH THE TERMS AND CONDITIONS CONTAINED IN THE CONTRACT AND PROJECTPERMITS. CONTROLS SHOWN ON THE CONTRACT DRAWINGS AND MENTIONED IN THE TECHNICALSPECIFICATIONS SHALL BE CONSIDERED MINIMUM REQUIREMENTS. THE CONTRACTOR SHALL EMPLOYWHATEVER SUPPLEMENTARY MEASURES NECESSARY TO PROTECT WETLANDS, WATERS, AND ADJACENTAREAS FROM DISTURBANCE OR DISCHARGE OF SEDIMENTS.3.THE CONTRACTOR SHALL BE RESPONSIBLE FOR PROVIDING SEDIMENT AND EROSION CONTROLS TOMEET THE CONDITIONS OF ALL APPLICABLE PERMITS AND REGULATIONS. SUCH CONTROLS SHALL BEINSTALLED WHEREVER THE POTENTIAL EXISTS FOR THE DISTURBANCE OF LAND OR THE TRANSPORT OFSEDIMENT.4.THE CONTRACTOR SHALL NOT DISTURB VEGETATED AREAS OUTSIDE OF THE WORK ZONE, EXCEPT TOTHE MINIMUM EXTENT NECESSARY FOR ACCESS AND ACCOMPLISHMENT OF THE WORK SHOWN.5.THE CONTRACTOR ALONE SHALL BE RESPONSIBLE FOR THE CONTROL OF EROSION AND SEDIMENTDISCHARGE THROUGHOUT THE DURATION OF THE PROJECT AND UNTIL FINAL STABILIZATION. IT SHALLBE HIS RESPONSIBILITY TO PROTECT THE RESERVOIR, BROOK, AND ADJACENT WETLANDS FROMSEDIMENT AND/OR POLLUTANTS ORIGINATING FROM ANY WORK DONE ON OR IN SUPPORT OF THEPROJECT, INCLUDING SEDIMENT DUE TO EROSION FROM STORMWATER RUNOFF.6.ALL NECESSARY PRECAUTIONS SHALL BE TAKEN TO PREVENT MIGRATION INTO WATER BY SILT,SEDIMENT, FUELS, SOLVENTS, LUBRICANTS, CONCRETE, GROUT, OR ANY OTHER POLLUTANTSASSOCIATED WITH CONSTRUCTION PROCEDURES.7.ACTUAL LOCATIONS OF EROSION CONTROLS AND BMPS MAY VARY DUE TO FIELD CHANGES, ONGOINGCONSTRUCTION, ACCESS NEEDS, WEATHER, ETC. THE CONTRACTOR SHALL BE RESPONSIBLE FORIDENTIFYING THESE CHANGES AND ADJUSTING EROSION CONTROLS AND BMP LOCATIONSACCORDINGLY. IN PARTICULAR, THE CONTRACTOR SHALL COORDINATE THE INSTALLATION ANDRELOCATION OF BMPS WITH PROJECT PHASING, AS NECESSARY.8.ALL EROSION CONTROLS AND BMPS SHALL REMAIN IN PLACE, EXCEPT AS OTHERWISE NECESSARY, UNTILCONSTRUCTION IS COMPLETED AND FINAL STABILIZATION IS ACHIEVED. ALL SILT FENCING SHALL BEREMOVED UPON SUBSTANTIAL COMPLETION OF THE PROJECT SUCH THAT ONLY STRAW WATTLES ARELEFT IN PLACE. STRAW WATTLES SHALL BE BROKEN UP AND SPREAD AS MULCH PRIOR TO FINALSTABILIZATION.9.THE CONTRACTOR SHALL POST COPIES OF THE PROJECT PERMITS AND AUTHORIZATIONS PROMINENTLYAT THE SITE. THE CONTRACTOR SHALL POST A SIGN WITH THE PROPER MADEP FILE NUMBERPROMINENTLY AT THE SITE. E D M M A T M A T T E J C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S J G D M A Y 2 0 1 6 1 7 2 0 2 9 . 0 0 7 M A T M A T E D M T E J 1 " = 2 0 ' G Z A G e o E n v i r o n m e n t a l , I n c . E n g i n e e r s a n d S c i e n t i s t s w w w . g z a . c o m P R O J E C T N O . D A T E : R E V I S I O N N O . D E S I G N E D B Y : P R O J M G R : D R A W N B Y : R E V I E W E D B Y : C H E C K E D B Y : S C A L E : P R E P A R E D B Y : P R E P A R E D F O R : R O B E R T S M E A D O W B R O O K C H A N N E L R E H A B I L I T A T I O N P R O J E C T N O R T H A M P T O N , M A S S A C H U S E T T S P R O P O S E D C O N D I T I O N S P L A N C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S D R A W I N G N G R A P H I C S C A L E 0 1 0 2 0 4 0 S C A L E I N F E E T · · · J G D G Z A G e o E n v i r o n m e n t a l , I n c . E n g i n e e r s a n d S c i e n t i s t s w w w . g z a . c o m P R O J E C T N O . D A T E : R E V I S I O N N O . D E S I G N E D B Y : P R O J M G R : D R A W N B Y : R E V I E W E D B Y : C H E C K E D B Y : S C A L E : P R E P A R E D B Y : P R E P A R E D F O R : P R O P O S E D C H A N N E L S E C T I O N S D R A W I N G M A Y 2 0 1 6 1 7 2 0 2 9 8 A S N O T E D 0 0 5 1 0 2 0 V E R T I C A L S C A L E I N F E E T 5 1 0 2 0 H O R I Z O N T A L S C A L E I N F E E T E D M R O B E R T S M E A D O W B R O O K C H A N N E L R E H A B I L I T A T I O N P R O J E C T N O R T H A M P T O N , M A S S A C H U S E T T S M A T M A T T E J C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S J G D J A N . 2 0 1 7 1 7 2 0 2 9 9 A S N O T E D G Z A G e o E n v i r o n m e n t a l , I n c . E n g i n e e r s a n d S c i e n t i s t s w w w . g z a . c o m P R O J E C T N O . D A T E : R E V I S I O N N O . D E S I G N E D B Y : P R O J M G R : D R A W N B Y : R E V I E W E D B Y : C H E C K E D B Y : S C A L E : P R E P A R E D B Y : P R E P A R E D F O R : P R O P O S E D C H A N N E L P R O F I L E A N D D E T A I L S D R A W I N G 0 0 1 2 4 V E R T I C A L S C A L E I N F E E T 1 0 2 0 4 0 H O R I Z O N T A L S C A L E I N F E E T E D M R O B E R T S M E A D O W B R O O K C H A N N E L R E H A B I L I T A T I O N P R O J E C T N O R T H A M P T O N , M A S S A C H U S E T T S M A T M A T T E J C I T Y O F N O R T H A M P T O N D E P A R T M E N T O F P U B L I C W O R K S T E J N 4 3412123 3 1 12