January 14, 2015 Page 1 of 2

2014 Bathymetric and Sediment Report

Mill Pond

Wayland, Massachusetts

Lycott Environmental (Lycott) was contracted (Contract # 793-14) by the Wayland Surface Water Quality

Commission (WSWQC) to conduct a bathymetric survey and a sediment survey in Mill Pond in 2014. In

accordance with this contract, the following document serves as a report to summarize the tasks

completed in 2014.

METHODS

A bathymetric survey was conducted by Lycott on December 4, 2014. Pre-loaded, 5-meter transects were slowly traversed using a small vessel equipped with a sonar device (Lowrance HDS-5 Fishfinder/Chartplotter) (Image 1). Sonar survey methods, including transect width, average speed, ping speed and frequency, closely followed recommendations provided in the ciBioBase User Reference Guide (Contour Innovations, LLC, 2012). In conjunction with the bathymetric survey, water depth and detritus (i.e., soft sediment (decaying organic matter), debris and silt) thickness were measured with an expandable, marked (6” intervals”) PVC rod at 102 point locations throughout Mill Pond (Image 2). Water depth was measured by lowering the PVC rod down through the water column until the detritus was reached. Subsequently, the PVC rod was then pushed through the detritus until hard bottom was reached. The difference between the two recorded depths (i.e., PVC rod measurement to detritus and PVC rod measurement to hard bottom) indicated the detritus thickness at that particular point. Additionally, the GPS location of each point was marked using a hand-held GPS unit (refer to Table 1 for raw data associated with the rod survey).

Image 1: Orthoimagery of pre-loaded 5-meter transects

Image 2: Orthoimagery of 102 rod measurement points

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2014 Mill Pond Report

January 14, 2015 Page 2 of 2

Following this survey, the collected sonar data was processed by a third party, ciBioBase. CiBioBase interpolates the gathered sonar data which results in the creation of continuous (i.e., raster) imagery depicting the bathymetry of the water body. This processed data was further analyzed in a GIS software program (ArcGIS 10.2.2) in order to produce a bathymetric map with one-foot contours displayed. Additionally, the water depth rod measurements collected at the 102 point locations were imported and overlaid on the bathymetry raster imagery in ArcGIS to assess the accuracy of the interpolated bathymetric raster data. Lastly, detritus thickness rod measurements were imported and interpolated in ArcGIS to produce a detritus thickness map with half-foot contour classifications depicted. RESULTS Results of the bathymetric survey indicated that Mill Pond has a maximum depth of 9.6 feet, an average depth of 5.1 feet, and an estimated water body volume of 13.5 acre-feet. In general, the majority of water depth rod measurements were within one foot (70%) and two feet (89%) of the interpolated ciBioBase bathymetric imagery output. Detritus thickness throughout Mill Pond averaged 0.72 feet, and a maximum of 4 feet was noted at the inlet location in the northern most section of the pond. Maps depicting the bathymetric and detritus thickness at Mill Pond are enclosed. CONCLUSION/RECOMMENDATION Excessive detritus buildup was noted at the inlet (0.28-acre area) and outlet (0.57-acre area) locations of Mill Pond, and to a lesser extent, along the shorelines of the central portion of the pond (0.76-acre area). In comparison to the rest of the pond, these areas would benefit most from hydro-rake management/detritus removal (refer to ‘Figure 3: Proposed Management Areas’ map). Removal of this excessive material will benefit this open water habitat via the removal of nutrients, increasing water retention, and reducing the rate of eutrophication in Mill Pond. Estimates for the 2015 management season are enclosed.

Figu re 1: Bathym etric Su rvey Map

21 Wes t Main Street • Spen cer, MA508-885-0101 • in fo@lycott.c om

Mill PondWayland, MA

Data Collec ted: 12/4/14Map Prepared:1/11/15For WSWQC (#793-14)Basem ap © 2013 Es ri

Legend1-foot contour*9' - 9.6'8.0' - 8.9'7.0' - 7.9'6.0' - 6.9'5.0' - 5.9'4.0' - 4.9'3.0' - 3.9'2.0' - 2.9'0' - 1.9'

Note: Contour intervals initate at 2' in order to improve legibility of the map.

±1:1,2500 70 14035

Feet

Figure 2: Detritus Thicknes s Ma p

21 Wes t Ma in Street • Sp encer, MA508-885-0101 • info @lyco tt.co m

Mill PondWayland, MA

Da ta Co llected: 12/4/14Ma p Prep a red:1/12/15Fo r WSWQC (#793-14)Ba s ema p © 2013 Es ri ±1:1,250

0 70 14035Feet

Half foot contours

<0.50.5 - 11 - 1.51.5 - 22 - 2.52.5 - 33 - 3.53.5 - 4

LegendDetritus Thickness (ft.)

Figure 3: Proposed Management Areas

Mill PondWayland, MA

Data Collected: 10/4/2014Map Prepared:1/06/2015For Wayland Surface Water Quality Committee (WSWQC)Basemap © 2013 Esri ±1:1,350

0 70 14035Feet 21 West Main Street • Spencer, MA

508-885-0101 • info@lycott.com

LegendPrimarySecondary

Note: Primary areas = highlyrecommended for removal of detritus

Secondary area = less highlyrecommended for removal of detritus

January 13, 2015 1

Table 1: Mill Pond 2014 Water Depth and Detritus Thickness Rod Measurements Raw Data

PT ID Latitude (DD) Longitude (DD) Water Depth to Soft Bottom (ft.)

Water Depth to Hard Pan(ft.)

Detritus (ft.) (Soft Bottom –

Hard Pan)

001 42.367425 -71.357472 7 7.5 0.5

002 42.367407 -71.357488 7 8 1.0

003 42.367409 -71.357636 6 6.5 0.5

004 42.367519 -71.357760 6.5 7 0.5

005 42.367563 -71.357614 7 7 0.0

006 42.367603 -71.357522 6.5 6.5 0.0

008 42.367656 -71.357372 7.5 8 0.5

009 42.367601 -71.357413 7 8 1.0

010 42.367561 -71.357546 4.5 5 0.5

011 42.367565 -71.357727 2.5 2.5 0.0

012 42.367729 -71.357670 7 7 0.0

013 42.367828 -71.357647 9 10 1.0

014 42.367750 -71.357416 6.5 6.5 0.0

015 42.367809 -71.357384 7 7 0.0

016 42.367739 -71.357458 9 9.5 0.5

017 42.367727 -71.357639 6.5 6.5 0.0

018 42.367676 -71.357758 4 6 2.0

019 42.367714 -71.357860 2 2 0.0

020 42.367802 -71.357792 6.5 7 0.5

021 42.367889 -71.357668 9 10.5 1.5

022 42.367879 -71.357557 9 10.5 1.5

023 42.367919 -71.357384 7 7 0.0

024 42.367970 -71.357423 4 6 2.0

025 42.367924 -71.357523 8.5 8.5 0.0

026 42.367904 -71.357724 9 9.5 0.5

027 42.367845 -71.357839 7 7.5 0.5

028 42.367848 -71.357932 4.5 5.5 1.0

029 42.367924 -71.358035 3.5 3.5 0.0

030 42.368060 -71.357928 6.5 7.5 1.0

January 13, 2015 2

PT ID Latitude (DD) Longitude (DD) Water Depth to Soft Bottom (ft.)

Water Depth to Hard Pan(ft.)

Detritus (ft.) (Soft Bottom –

Hard Pan)

031 42.368107 -71.357745 7.5 8 0.5

032 42.368118 -71.357620 6.5 7.5 1.0

033 42.368140 -71.357539 5 6 1.0

034 42.368168 -71.357563 5 5.5 0.5

035 42.368094 -71.357729 7 7 0.0

036 42.368078 -71.357785 7 7.5 0.5

037 42.368057 -71.357922 5.5 6 0.5

038 42.368031 -71.358040 2.5 5 2.5

039 42.368082 -71.358112 2.5 3 0.5

040 42.368202 -71.357971 6 6 0.0

041 42.368195 -71.357803 6.5 6.5 0.0

042 42.368227 -71.357717 5.5 6 0.5

043 42.368176 -71.357596 6 6 0.0

044 42.368219 -71.357598 4.5 5.5 1.0

045 42.368294 -71.357730 5 5 0.0

046 42.368242 -71.357726 5 5 0.0

047 42.368233 -71.357857 7 7 0.0

048 42.368268 -71.358031 6.5 7.5 1.0

049 42.368321 -71.358080 4.5 5 0.5

050 42.368457 -71.357956 4 4.5 0.5

051 42.368477 -71.357865 6 6 0.0

052 42.368478 -71.357769 7 9 2.0

053 42.368462 -71.357669 5.5 5.5 0.0

054 42.368476 -71.357666 1.5 3.5 2.0

055 42.368569 -71.357800 4.5 4.5 0.0

056 42.368550 -71.357699 6 6.5 0.5

057 42.368536 -71.357782 4.5 5 0.5

058 42.368512 -71.357849 4.5 5 0.5

059 42.368514 -71.357922 4 4.5 0.5

January 13, 2015 3

PT ID Latitude (DD) Longitude (DD) Water Depth to Soft Bottom (ft.)

Water Depth to Hard Pan(ft.)

Detritus (ft.) (Soft Bottom –

Hard Pan)

060 42.368669 -71.357997 2.5 4 1.5

061 42.368729 -71.357865 4.5 4.5 0.0

062 42.368696 -71.357732 4.5 5.5 1.0

063 42.368659 -71.357688 2.5 3.5 1.0

064 42.368709 -71.357666 3.5 4.5 1.0

065 42.368750 -71.357774 3 5 2.0

066 42.368742 -71.357824 2.5 4 1.5

067 42.368811 -71.357849 2.5 4 1.5

068 42.368859 -71.357734 2.5 5 2.5

069 42.368855 -71.357671 1.5 3.5 2.0

070 42.368893 -71.357652 1.5 4 2.5

071 42.368906 -71.357680 2 5 3.0

072 42.368953 -71.357865 2 4 2.0

073 42.369025 -71.357824 1 4.5 3.5

074 42.369037 -71.357816 1.5 4.5 3.0

075 42.369059 -71.357628 1.5 3.5 2.0

076 42.369074 -71.357631 1 3 2.0

077 42.369209 -71.357713 2 3.5 1.5

078 42.369259 -71.357734 1 1.5 0.5

079 42.369236 -71.357737 1 5 4.0

080 42.369119 -71.357794 1.5 2 0.5

081 42.369083 -71.357843 1 4.5 3.5

082 42.367047 -71.357292 5.5 7 1.5

083 42.367105 -71.357228 5.5 6 0.5

084 42.367175 -71.357190 5.5 7.5 2.0

086 42.367089 -71.357057 4.5 5 0.5

087 42.366939 -71.357103 3.5 6 2.5

088 42.366864 -71.357131 3 5 2.0

089 42.366861 -71.357116 1.5 2 0.5

January 13, 2015 4

PT ID Latitude (DD) Longitude (DD) Water Depth to Soft Bottom (ft.)

Water Depth to Hard Pan(ft.)

Detritus (ft.) (Soft Bottom –

Hard Pan)

090 42.367011 -71.357162 1 2.5 1.5

091 42.367425 -71.357472 5.5 5.5 0.0

094 42.367407 -71.357488 7 7.5 0.5

095 42.367238 -71.357147 6 6 0.0

096 42.367210 -71.357201 6.5 8 1.5

097 42.367172 -71.357234 7 7 0.0

098 42.367208 -71.357398 7 7.5 0.5

099 42.367281 -71.357408 6.5 7.5 1.0

100 42.367310 -71.357316 7.5 7.5 0.0

101 42.367352 -71.357317 7 7.5 0.5

102 42.367355 -71.357375 7 8 1.0

103 42.367304 -71.357475 6.5 6.5 0.0

104 42.367311 -71.357500 7.5 9 1.5

105 42.367366 -71.357515 7 7.5 0.5

106 42.367388 -71.357465 6.5 7.5 1.0

The mechanical hydro-raking project would span three years if the two primary areas (Inlet and Outlet) and the secondary area (Center) of pond were adopted as proposed. Based on sediment probing measurements collected on December 4th, there is an average of 2.13 feet (Inlet), 1.05 feet (Outlet) and 1.43 (Middle) of collected detritus (debris, leaf litter, organic decaying matter, soft sediment, silt). Below is a table estimating the amount of detritus removal and the duration of each hydro-rake event based on location.

Proposed Detritus

Removal Area

Acre Area

Avg. Detritus

Depth (ft)

Material yds3 (Wet)

Estimate Material

Removal*

Estimate yds3 (Dry)**

Estimate Rake Time (Days)***

Inlet 0.28 2.13 962 641 160 4-5

Outlet 0.57 1.05 953 635 159 5-6

Center 0.76 1.43 1,752 1,168 292 8-9

* Assumes two-thirds of material can be effectively removed by hydro-raking

** Assumes material will de-water by at least 50% immediately upon removal and another 25-35% prior to disposal

*** Estimate hydro-rake days dependent on transportation time of material to off-load location

Anticipated costs are outlined in the table below:

Mgmt. Task

Activity Description Cost

NOI Prepare and submit a NOI to MassDEP and the Wayland Conservation Commission (includes attendance at NOI hearing, does not included fee to obtain certified abutters list, certified abutter mailing and public hearing notice in local newspapers – up to $500 in additional costs).

Note: The NOI may require an aquatic vegetation survey and wildlife habitat survey.

$2,000

Detritus Removal

Mobilization / Demobilization - $1,500 Daily rake fee for 7.5 on -water operating hours - $1,500 Purchase and installation of erosion control measures along

shoreline of offload area - $500 Use and installation of turbidity / fragment curtain at outlet - $0

$9,500 (Inlet)

$9,500 (Outlet)

$13,500 (Center)

On-shore Material Collection / Disposal

Onsite stockpiling and composting per week with use of dewatering tub and rental of Bobcat Versahandler with operator

$2,500 (Inlet)

$2,500 (Outlet)

$5,000 (Center)

Onsite dewatering in containers with rental of Bobcat Versahandler with operator and offsite disposal / composting

$6,000 (Inlet)

$6,000 (Outlet)

$12,000 (Center)