2014 Mill Pond Bathymetric & Sediment Survey

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). ! ( ( ! ( ! ( !

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

January 14, 2015

Image 2: Orthoimagery of 102 rod measurement points

Page 1 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.

2014 Mill Pond Report January 14, 2015

Page 2 of 2

Fi gu re1:Bathym etri c Su rvey Map Legend

1-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.

Mill Pond Wayland, MA

DataCol l ec ted:12/ 4/ 14 MapPrepared: 1/ 1 1/ 15 For WSWQC( #79314) Bas em ap© 2013Es ri

0

35

70

1: 1, 250 Feet

140

±

21Wes t Mai n Street • Spen c er,MA 5088850101• i n fo@l yc ott. c om

Fi gure 2:Detri tus Thi cknes s Ma p Legend Detritus Thickness (ft.) <0.5 0.5 - 1 1 - 1.5 1.5 - 2 2 - 2.5 2.5 - 3 3 - 3.5 3.5 - 4

Half foot contours

Mill Pond Wayland, MA

Da ta Co llected:12/ 4/ 14 Ma p Prep a red: 1/ 12/ 15 Fo r WSWQC( #79314) Ba s ema p © 2013Es ri

0

35

70

1: 1, 250 Feet

140

±

21Wes tMa i nStreet• Sp enc er,MA 5088850101• i nf o @lyc o tt. co m

Figure 3: Proposed Management Areas Legend Primary

Secondary Note: Primary areas = highly recommended for removal of detritus Secondary area = less highly recommended for removal of detritus

Mill Pond Wayland, MA

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

0

35

70

1:1,350 Feet

140

±

21 West Main Street • Spencer, MA 508-885-0101 • info@lycott.com

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

January 13, 2015

PT ID

Latitude (DD)

Longitude (DD)

Water Depth to Soft Bottom (ft.)

Water Depth to Hard Pan(ft.)

001

42.367425

-71.357472

7

7.5

Detritus (ft.)

(Soft Bottom â&#x20AC;&#x201C; Hard Pan) 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

1

January 13, 2015

PT ID

Latitude (DD)

Longitude (DD)

Water Depth to Soft Bottom (ft.)

Water Depth to Hard Pan(ft.)

031

42.368107

-71.357745

7.5

8

Detritus (ft.)

(Soft Bottom â&#x20AC;&#x201C; Hard Pan) 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

2

January 13, 2015

PT ID

Latitude (DD)

Longitude (DD)

Water Depth to Soft Bottom (ft.)

Water Depth to Hard Pan(ft.)

060

42.368669

-71.357997

2.5

4

Detritus (ft.)

(Soft Bottom â&#x20AC;&#x201C; Hard Pan) 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

3

January 13, 2015

PT ID

Latitude (DD)

Longitude (DD)

Water Depth to Soft Bottom (ft.)

Water Depth to Hard Pan(ft.)

090

42.367011

-71.357162

1

2.5

Detritus (ft.)

(Soft Bottom â&#x20AC;&#x201C; Hard Pan) 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

4

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 Inlet Outlet Center

Acre Area 0.28 0.57 0.76

Avg. Detritus Depth (ft) 2.13 1.05 1.43

Material yds3 (Wet) 962 953 1,752

Estimate Material Removal* 641 635 1,168

Estimate yds3 (Dry)** 160 159 292

Estimate Rake Time (Days)*** 4-5 5-6 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 NOI

Detritus Removal

On-shore Material Collection / Disposal

Activity Description

Cost

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).

$2,000

Note: The NOI may require an aquatic vegetation survey and wildlife habitat survey.  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 Onsite stockpiling and composting per week with use of dewatering tub and rental of Bobcat Versahandler with operator Onsite dewatering in containers with rental of Bobcat Versahandler with operator and offsite disposal / composting

$9,500 (Inlet) $9,500 (Outlet) $13,500 (Center)

$2,500 (Inlet) $2,500 (Outlet) $5,000 (Center) $6,000 (Inlet) $6,000 (Outlet) $12,000 (Center)