Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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PHOSPHORUS CONTROL ACTION PLAN 

and Total Maximum Daily (Annual Phosphorus) Load Report 

Daigle Pond- New Canada 

Aroostook County, Maine 

Daigle Pond PCAP - TMDL Report 

Maine DEPLW - 0789

Maine Department of Environmental Protection 

and Maine Association of Conservation Districts 

Final EPA Review Document– September 27, 2006 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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DAIGLE POND - New Canada 

Phosphorus Control Action Plan (PCAP) 

Table of Contents

 

Acknowledgments................................................................................... 3

Summary Fact Sheet ............................................................................... 4-5

Project Premise and Study Methodology.................................................... 6-7

DESCRIPTION of WATERBODY and WATERSHED

 Figure 1: Map of Daigle Pond Watershed................................................... 8

 Drainage System...................................................................................... 9

 Water Quality Information....................................................................... 9-10

 Principal Uses & Human Development.............. ....................................... 10

 Fish Assemblage and Fisheries Status....... .............................................. 11

 General Soils Description......................................................................... 12

 Land Use Inventory............................................................................... 12

 Figure 2: Daigle Pond Watershed Land Uses............................................. 12

Descriptive Land Use and External Phosphorus Export Estimates

Developed Lands

 Table 1: Land Use Inventory and Phosphorus Loads.................................... 13 

 Agriculture............................................................................................ 14

Actively Managed Forest Land................................................................. 14 

 Shoreline Roads................................................................................... 14

 Non-Shoreline Development................................................................... 15

 Non-Shoreline Roads............................................................................. 15

 Low Density Residential......................................................................... 15

Phosphorus Loading from Non-Developed Lands and Water

 Inactive/Passively Managed Forests......................................................... 15

 Other Non-Developed Land Areas............................................................. 15

 Atmospheric Deposition (Open Water)....................................................... 15

PHOSPHORUS LOADS – Watershed, Sediment and In-Lake Capacity................ 16

PHOSPHORUS CONTROL ACTION PLAN................................................... 17

 Recent and Current NPS/BMP Efforts.......................................................... 17

 Recommendations for Future Work.......................................................... 18-20

 Water Quality Monitoring Plan..................................................................... 20

PCAP CLOSING STATEMENT................................................................... 20

Shoreline Development.......................................................................... 14 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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APPENDICES 

DAIGLE POND - New Canada 

Total Maximum Daily (Annual Phosphorus) Load 

 Introduction to Maine Lake TMDLs and PCAPs ..................................... 22 

 Water Quality, Priority Ranking, and Algae Bloom History ....................... 23 

 Natural Environmental Background Levels ........................................... 23 

 Water Quality Standards and Target Goals .......................................... 23-24 

 Estimated Phosphorus Export by Land Use Class (Table 2) .................... 24-27 

 Linking Water Quality and Pollutant Sources ........................................ 27 

 Future Development................................................................... 28 

 Internal Lake Sediment Phosphorus Mass ...................................... 28 

 Total Phosphorus Retention Model................................................ 29 

 Load (LA) and Wasteload (WLA) Allocations .................................... 29-30 

 Margin of Safety and Seasonal Variation......................................... 30 

Daily TP Pollutant Load Calculations for Daigle Pond..........................31

 Public Participation ......................................................................... 33 

 Stakeholder and Public Review Process and Comments ........................ 33-34 

 Literature - Lake Specific and General References ................................ 35-40 

 

ACKNOWLEDGMENTS 

 In addition to Maine DEP (Division of Environmental Assessment - Lakes 

Assessment Section and Watershed Management Division-Augusta and Presque Isle) 

and U.S. EPA New England Region I staff, the following individuals, groups and 

agencies were instrumental in the preparation of this Daigle Pond combined 

Phosphorus Control Action Plan and Total Maximum Daily Load report: MACD staff 

(Forrest Bell, Fred Dillon, Jennifer Jespersen, and Tricia Rouleau); Maine Department 

of Agriculture (David Rocque); Maine Forest Service (Chris Martin); Maine Department 

of Inland Fisheries and Wildlife (Dave Basley); the Saint John Valley Soil and Water 

Conservation District (Heidi Royal), and Maine Volunteer Lake Monitoring Program 

volunteers Don Eno and Beau Daigle (1998-2001). 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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 Background

 DAIGLE POND (Midas No. 1665) is a 34- acre 

colored pond located in New Canada Plantation in 

Aroostook County, Maine. Daigle Pond has a direct 

drainage (see map at right and on pg. 8) area of 

approximately 2.2 square miles; a maximum depth of 12 feet 

(4 meters), a mean depth of 7 feet (2 meters); and a 

relatively high flushing rate of 21.3 times per year. 

Historical Information

 Daigle Pond is a shallow, impounded dual-basin pond 

which has historically received non-point source (NPS) 

runoff from surrounding agricultural lands and roads 

(Bouchard 1995). Nutrient contamination, and persistent 

nuisance algal blooms, have been documented in Daigle 

Pond since 1977. In the early 1990’s a Watershed Survey 

identified 47 separate NPS problem sites (SJV-SWCD 

1996). In addition to residential lots, roads and agricultural 

NPS sites, the survey found that water quality was affected 

by a deteriorating causeway culvert between the upper and 

lower basins which caused stagnation of the water in the 

upper basin (DPRC 2003). 

 NPS pollution in Daigle Pond stems primarily from soil 

erosion in the surrounding watershed and stormwater 

runoff from area roads and agricultural sites (external load). 

Soil erosion can have far reaching impacts, as soil particles 

effectively transport phosphorus, which serves to 

“fertilize” the lake and decreases water clarity. Because 

Daigle Pond is an impounded stream, it collects a 

substantial amount of sediments over time. When 

resuspended (internal load), these nutrient rich sediments 

can be a source of high phosphorus (Bouchard 1996), 

especially during the warm summer months. Excess 

phosphorus can also harm fish habitat and lead to nuisance 

algae blooms—floating mats of green scum—or dead and 

dying algae. Studies have shown that as lake water clarity 

decreases, lakeshore residential property values also decline. 

 Although there have been significant efforts to reduce erosion and phosphorus loading in the watershed, 

phosphorus levels are still high enough to affect water quality and promote algal growth. Daigle Pond is listed 

by DEP as “water quality limited” which means that it is well below the minimum standard. It is also listed on 

Maine’s 303(d) list of impaired waterbodies. 

Daigle Pond - New Canada 

Phosphorus Control Action Plan 

Summary Fact Sheet

Key Terms

• Flushing rate refers to how often the water in the entire lake is replaced on an annual basis.

• Watershed is a drainage area or basin in which all land and water areas drain or flow toward a central collector 

such as a stream, river, or lake at a lower elevation.

• Phosphorus: is one of the major nutrients needed for plant growth. It is naturally present in small amounts and 

limits the plant growth in lakes. Generally, as phosphorus increases, the amount of algae also increases. 

Daigle Pond Historical Water Clarity

0

1

2

3

4

1977 1980 1989 1995 1998 1999 2003

Meters Below Surface

Daigle Pond Min. Transparency DEP Standard Trend

Daigle Pond’s minimum water clarity has deteriorated over the 

period of record. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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What We Learned

 The land use assessment conducted for 

the Daigle Pond watershed helped to 

determine the potential sources of 

phosphorus that may run off from land 

areas during storm events and springtime 

snow melting. This assessment utilized 

many resources, including generating and 

interpreting maps, inspecting and verifying 

aerial photos using local knowledge, and 

visiting the watershed. 

 A land-use model (p.7) estimated that 

approximately 1,269 kg of phosphorus is 

exported annually (external load) to Daigle 

Pond from the direct watershed (p.25). The 

bar chart (right) illustrates the land area 

representative land uses as compared to the 

phosphorus export load for each land use. 

 Sampling data collected in 1995 revealed that the amount of total phosphorus (TP) being recycled internally 

(internal load - 26 kg/year) from Daigle Pond bottom sediments during the summer-time is approximately 22% 

of the pond's natural capacity (116 kg/year) for in-lake phosphorus assimilation (assuming a target goal of 16

ppb for a colored lake). 

Phosphorus Reduction Needed

 Daigle Pond’s average summertime TP concentration (originating from a combination of external and 

internal loading) approximates 50 ppb (365 kg) - equal to an additional 248 kg more than the lake’s natural 

capacity. Including a 3.65 kg allocation for future development, the total annual amount of phosphorus needed to 

be reduced to support Maine water quality standards (algal bloom-free total phosphorus concentrations of 16 ppb 

or less) in Daigle Pond approximates 252 kg (see In-Lake Concentration Method p.16).

What You Can Do To Help!

 As a watershed resident, there are many things you can do to protect the water quality of Daigle Pond. 

Lakeshore owners can use phosphorus-free fertilizers and maintain natural vegetation adjacent to the lake. 

Agricultural and commercial land users can consult the St. John Valley Soil and Water Conservation District or 

the Maine Department of Environmental Protection for information regarding Best Management Practices

(BMPs) for reducing phosphorus loads. Watershed residents can always become involved by participating in 

events sponsored by State agencies and local organizations. The estimated phosphorus loading to Daigle Pond 

originates from both shoreline and non-shoreline areas, so all watershed residents must take ownership of 

maintaining suitable water quality. Lake stakeholders and watershed residents in New Canada and Fort Kent can 

learn more about their lake and the many resources available, including review of the Daigle Pond Phosphorus 

Control Action Plan and TMDL report. Following final EPA approval, copies of this detailed report, with 

recommendations for future NPS/BMP work, will be available online at www.maine.gov/dep/blwq/

docmonitoring/tmdl2.htm, or can be viewed and/or copied (at cost) at Maine DEP offices in Presque Isle and 

Augusta (Bureau of Land and Water Quality, Ray Building, AMHI Campus). 

Key Terms 

• Total Phosphorus (TP) - the total concentration of phosphorus found in the water including organic and 

inorganic forms. 

• Best Management Practices are techniques to reduce sources of polluted runoff and their impacts. BMP’s are 

low cost, common sense approaches to reduce storm runoff and velocity to keep soil out of lakes and tributaries. 

• TMDL, an acronym for Total Maximum Daily Load, represents the total amount of a pollutant (e.g., 

phosphorus) that a waterbody can receive on an annual basis and still meet water quality standards. 

 Land Use Areas and Phosphorus Loadings

Daigle Pond Direct Watershed

33%

1%

12%

3%

48%

1% <1% <1% 2%

96%

<1% <1% 0%

20%

40%

60%

80%

100%

Ag Land N onShoreline

Dev.

Non- D ev.

Land

Active

Forest

Surf ace

Water

Shoreline

Dev.

% Total

Land Area Total P

Agricultural land uses make up the highest proportion of total phosphorus 

exported to Daigle Pond (see pages 12-15 for explanation). 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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Project Premise 

 This lakes PCAP-TMDL project, funded through a Clean Water Act Section 319-grant from the 

United States Environmental Protection Agency (EPA), was directed and administered by the Maine 

Department of Environmental Protection (Maine DEP) under contract with the Maine Association of 

Conservation Districts (MACD), from 2005 to 2006. 

 The objectives of this project were twofold: First, a comprehensive land use inventory was 

undertaken to assist Maine DEP in developing a Phosphorus Control Action Plan (PCAP) and a 

Total Maximum Daily Load (TMDL) report for the Daigle Pond watershed (see study methodology, 

p.7). Simply stated, a TMDL is the total amount of phosphorus that a lake can receive without 

harming water quality. Maine DEP, with assistance from the MACD, will fully address and 

incorporate public comments before final submission to the US EPA. (For more specific information 

on the TMDL process and results, refer to the Appendices or contact Dave Halliwell at the Maine 

DEP Augusta Office at 287-7649 or at david.halliwell@maine.gov). 

 Secondly, watershed assessment work was conducted by the Maine DEP-MACD project team to 

help assess total phosphorus reduction techniques that would be beneficial for the Daigle Pond 

watershed. The results of this assessment include recommendations for future conservation work in 

the watershed to help citizens, organizations, and agencies restore and protect Daigle Pond. 

Note: To protect the confidentiality of landowners in the Daigle Pond watershed, site-specific 

information has not generally been provided as part of this PCAP-TMDL report.

 This Phosphorus Control Action Plan (PCAP) report compiles and 

refines land use data derived from various sources, including the 

Maine Office of Geographic Information Systems, the St. John Valley 

Soil & Water Conservation District (SJV-SWCD), and the Maine 

Forest Service (MFS). Local citizens, active and/or developing 

watershed organizations, and conservation agencies will benefit from 

this compilation of both historical and recently collected data as well 

as the watershed assessment and the NPS Best Management 

Practice (BMP) recommendations. Above all, this document is intended to help Daigle Pond 

stakeholder groups to effectively prioritize future BMP work in order to obtain the funding resources 

necessary for further NPS pollution mitigation work in their watershed. 

Study Limitations

 Land use data gathered for the Daigle Pond watershed is as accurate as possible given all of the 

available information and resources utilized. However, final numbers for the land use analysis and 

phosphorus loading numbers are approximate, and should be viewed only as carefully researched 

estimations. Land uses in the Daigle Pond watershed have changed since the 1995 land-use data 

was developed, and continue to change each growing season. As such, a combination of GIS and 

field observations would likely have provided a more accurate summary of watershed land uses. 

Nonpoint Source (NPS) 

Pollution - is polluted runoff 

that cannot be traced to a 

specific origin or starting 

point, but accumulates from 

overland flow from many 

different watershed sources 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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Study Methodology 

 Daigle Pond background information was obtained using several methods, including a review of 

previous surveys of the pond and watershed, numerous phone conversations and personal 

communications with regional organizations and state agencies, and a field tour of the watershed. 

 Land use data were determined using several methods, including (1) Geographic Information 

System (GIS) map analysis, (2) analysis of topographic maps, and (3) analysis of aerial 

photographs. Much of the non-developed land use area (i.e., forest, wetland, grassland) was 

determined using a GIS layer which is a combination of Maine Gap Analysis (GAP) landcover and 

USGS Multi Resolution Landcover Characterization (MRLC) landcover layers. It was created at the 

request of Maine DEP Bureau of Land and Water Quality (BLWQ) staff. It includes those classes in 

each layer which are best suited to calculating impermeability of watersheds. Both MRLC and GAP 

(and so Maine COMBO) are based on 1995 LandSat imagery. The developed land use areas were 

obtained using the best possible information available through analysis of methods 1 through 3 listed 

above. 

 Final adjusted phosphorus loading numbers (see Table 2, page 25) were modeled using overlays 

of soils and slope. All of the land use coverage data for agricultural areas were re-configured using 

aerial overlays, and reviewed and confirmed by the SJV-SWCD in conjunction with the USDA/NRCS. 

Information regarding forest harvest operations were reviewed by the Maine Forest Service, 

Department of Conservation. 

 Roadway widths were estimated from previous PCAP reports where actual measurements were 

made for the various road types. In general, state-owned roads were found to be 22 meters wide; 

town-owned roads were found to be 16 meters wide; and privately-owned roads were found to be 6 

meters wide. GIS was used to calculate total road surface area. 

 

 

GIS—or geographic information system combines layers of 

information about a place to give you a better understanding of that 

place. The information is often represented as computer generated 

maps. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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Figure 1. Map of Daigle Pond Direct Watershed* 

* The Daigle Pond direct watershed area has been adjusted to reflect changes in the landscape which have affected the 

direction of water flow. According to the St. John Valley Soil and Water Conservation District, with time and severe rain 

events, gullies have diverted some of the flow from the Cross Lake watershed (to the east) to the Daigle Pond watershed. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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DAIGLE POND Phosphorus Control Action Plan

DESCRIPTION of WATERBODY (MIDAS Number 1665) and WATERSHED

DAIGLE POND is a 34-acre (14 hectare) 

colored waterbody situated in the town of New 

Canada (DeLorme Atlas, Map 68), within 

Aroostook County, Maine. Daigle Pond has a 

direct watershed area (see Figure 1) of 

approximately 1,417 acres (2.2 square miles) 

including pond surface area. The Daigle Pond 

direct watershed is located within two towns: New 

Canada (70%) and Fort Kent (30%). Daigle Pond 

has a maximum depth of 12 feet (4 meters), 

overall mean depth of 7 feet (2 meters), and a 

relatively high flushing rate of 21.3 times/year. 

Drainage System: 

 Daigle Pond is an impounded stream divided into two basins by a causeway culvert. The pond 

was created in 1874 when a dam was constructed to power a sawmill on Daigle Brook. Daigle Pond’s 

only outflow is the man-made concrete dam outlet on the southern end of the pond. There are no 

boat launches on Daigle Pond - the only access is by paved road. Daigle Brook, a water quality 

impaired 303(d) listed stream, flows into the pond from the northwest and into 303(d) -listed Cross 

Lake to the southeast. The poor water quality of Daigle Brook is caused by excessive pollutants (total 

phosphorus) from Daigle Pond and the brook’s direct watershed within the Cross Lake drainage. 

 

Water Quality Information 

 Daigle Pond is listed on the Maine DEP’s 2004 303(d) list of lakes that do not meet State water 

quality standards. Daigle Brook is also listed on the Maine DEP’s Non-Point Source (NPS) Priority 

Watersheds list. Therefore, a combined Phosphorus Control Action Plan and TMDL report was 

prepared during the spring-summer of 2006. 

Daigle Pond Direct Watershed: The direct watershed 

refers to the land area that drains to a waterbody without 

first passing through an associated lake or pond. 

Non Point Source Priority Watersheds

Waterbodies within designated NPS priority 

watersheds have significant value from a regional or 

statewide perspective and have water quality that is 

either impaired or threatened due to NPS water 

pollution. This list identifies watersheds where state 

and federal agency resources for NPS water pollution 

prevention or restoration should be targeted. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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 Based on Secchi disk transparencies (SDT), measures of 

total phosphorus (TP), and chlorophyll-a, (Chl-a), the water 

quality of Daigle Pond is considered to be poor and the 

potential for nuisance summertime algae blooms is high (Maine 

VLMP 2005). Together, these water quality data document a 

trend of increasing trophic state, in direct violation of the 

Maine DEP Class GPA lakes water quality criteria requiring a 

stable or decreasing trophic state. 

 A variety of nonpoint sources of pollution may be 

contributing to the poor water quality in Daigle Pond. The water 

quality of Daigle Pond is heavily influenced by runoff events 

from the watershed. During storm events, nutrients such as 

phosphorus – naturally found in Maine soils - drain into the 

pond from the surrounding watershed by way of streams and 

overland flow, eventually being deposited and stored in pond 

sediments (26 kg based on 1995 measures). Years of soil 

erosion have resulted in a buildup of sediment in the Daigle 

Pond, which contributes to internal phosphorus loading 

(Bouchard 1996). 

 Phosphorus is naturally limited in lakes and can be thought 

of as a fertilizer, a primary food for plants, including algae. When lakes receive excess phosphorus 

from NPS pollution, it “fertilizes” the lake by feeding the algae. Too much phosphorus can result in 

nuisance algae blooms, which can damage the ecology and aesthetics of a lake, as well as the 

economic well-being of the entire lake watershed. 

 Historically, poor water quality in Daigle Pond has been attributed to nonpoint source runoff from 

primarily agricultural land and roads. A Watershed Survey conducted in the early 1990’s revealed 47 

separate problem sites in the Daigle Pond watershed. The primary sources of nonpoint source 

pollution were identified as residential (driveways, house lots, roads) and agricultural sites (row crops, 

animal feedlots) (SJV-SWCD 1996). Additional organic and nutrient loading to Daigle Pond has been 

noted in recent years (2004-2005), when poor potato seasons resulted in a large number of cull 

potatoes and excess potato waste was spread on fields or used as feed at cattle operations (Heidi 

Royal/SJV-SWCD, Personal Communication). 

 

Principle Uses & Human Development: 

 The prevalent human uses of the Daigle Pond 

watershed are primarily agricultural (48%) (Figure 2). 

With approximately 64% (903 acres) of the land area 

consisting of developed land, NPS pollution is a significant 

concern for the watershed. Consequently, Daigle Pond is 

on the State’s 303(d) list due primarily to excessive 

phosphorus (sediments), lake enrichment and the 

historical prevalence of nuisance algal blooms. 

Stabilizing eroding waterways with stone rip-rap 

helps to prevent soil erosion. 

BEFORE AFTER 

Secchi Disk Transparency - 

a vertical measure of the transparency of water (ability of light to 

penetrate water) obtained by lowering a black and white disk into the 

water until it is no longer visible. 

Trophic state - the degree of 

e u t r o p h i c a t i o n o f a l a k e . 

Transparency, chlorophyll-a levels, 

phosphorus concentrations, amount of 

macrophytes, and quantity of 

dissolved oxygen in the hypolimnion 

can all be used to assess trophic state. 

Chlorophyll-a is a measurement of 

the green pigment found in all plants 

including microscopic plants such as 

algae. It is used as an estimate of algal biomass; the higher the Chl-a

number, the higher the amount of algae in the lake. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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 Daigle Pond Fish Assemblage & Fisheries Status 

 Based on records provided by the Maine Department of Inland Fisheries and Wildlife 

(Maine DIF&W) and recent communication with fisheries biologist Dave Basley (Region G, 

Ashland DIF&W office), 36-acre (maximum depth 12 feet) Daigle Pond (New Canada, Cross 

Lake drainage system) is currently managed as a coldwater (brook trout) fishery. Daigle 

Pond was originally surveyed by Maine DIF&W in 1959, while their lake fisheries report was 

previously revised in 1963 and 2001. A total of 5 native indigenous fish species are found to 

occur, including brook trout, banded killifish, and three northern minnow species (pearl dace, 

finescale dace, and northern redbelly dace). Daigle Pond was chemically reclaimed in 1967 

(rotenone treatment) "to remove competing species and provide for intensive management of 

brook trout." In the years immediately following reclamation, an attractive sport fishery was 

created with annual stockings of fingerling brook trout. In recent years, in-lake habitat 

degradation, in terms of poor water quality, has reduced the number of anglers fishing Daigle 

Pond. 

 

 

 

 

 

 Generally, increases in trophic state as result of nonpoint source phosphorus loading 

increases water temperature and reduces dissolved oxygen concentrations. Improvements in 

water quality, reducing the prevalence of nuisance summertime algal blooms, may serve to 

enhance fisheries conditions in Daigle Pond. Given that the trophic state of Daigle Pond has 

been disturbed by cumulative human impacts over the past several decades - then a 

significant reduction in the total phosphorus loading from the Daigle Pond watershed may 

lead to maintaining in-lake nutrient levels within the natural assimilative capacity of this lake to 

effectively process total phosphorus - and enhance existing brook trout fisheries. Brook trout 

fisheries in downstream Daigle Brook would also be expected to benefit. 

Brook trout 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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General Soils Description

 The Daigle Pond watershed is characterized by the following general soil association 

(Ferwerda et al. 1997): Plaisted-Penquis-Thorndike-Howland, which consists of the somewhat 

excessively drained Thorndike silt loam, the well drained Plaisted gravelly loam, and the 

moderately well drained Howland gravelly loam. These soils, formed from glacial till parent 

materials, have moderate permeability in the solum, and moderately slow or slow permeability 

in the dense substratum. Some areas of moderately well drained Machias gravelly loam 

(formed over gravel and cobble stream deposits) also occur along Daigle Brook. Although the 

loamy surface soils allow for high water holding capacity, approximately 380 acres of the soils 

in the Daigle Pond watershed are highly erodible. Of the 679 acres of agricultural land in the 

watershed, 113 acres (17%) are classified as highly erodible and 566 acres (83%) are 

considered potentially highly erodible. 

 Soils in the Daigle Pond watershed generally fall within the C and D hydrologic soil groups, 

which have slow and very slow infiltration rates, allowing for the potential for greater amounts 

of surface runoff. Surface runoff in the watershed is slow to rapid, depending on slope. 

 Land Use Inventory

 The results of the Daigle Pond 

watershed land use inventory are 

depicted in Figure 2 (right) and Table 1

(p.13) The dominant land uses in the 

watershed are agriculture and 

unmanaged forest. In Table 1, 

watershed land uses are categorized by 

developed land vs. non-developed land. 

The developed land area comprises 

approximately 64% of the watershed 

and the undeveloped land, including the 

water surface area of Daigle Pond, 

comprises the remaining 36% of the 

watershed. These numbers may be 

used to help make future planning and 

conservation decisions relating to the 

Daigle Pond watershed. The 

information in Table 1 was also used as 

a basis for preparing the Total Maximum 

Daily (Annual Phosphorus) Load report 

(see Appendices). Figure 2: Map of Daigle Pond watershed land uses. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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Table 1. Daigle Pond Direct Watershed—Land Use Inventory and External Phosphorus Loads 

 Land Land TP Export TP Export 

LAND USE CLASS Area Area Load Total 

 Acres % kg TP % 

 

Agricultural Land 

Hayland (non-manured) 131 9% 42 3% 

Hayland (manured) 60 4% 44 3% 

Row Crops 367 26% 407 32% 

Animal Feedlot/Barnyard 13 1% 681 54% 

Pasture (Grazed Meadows) 108 8% 44 3% 

Sub-Totals 679 48% 1,218 96% 

 

Actively Managed Forest 162 12% 7 <1% 

Sub-Totals 162 12% 7 <1% 

 

Shoreline Development 

Low Density Residential 11 <1% 3 <1% 

Roads 6 <1% 5 <1% 

Sub-Totals 17 1% 8 <1% 

 

Non-Shoreline Development 

Roads 23 >1% 17 >1% 

Low Density Residential 22 >1% 6 <1% 

Sub-Totals 45 3% 23 2% 

 

Total: DEVELOPED LAND 903 64% 1,256 99% 

 

Non-Developed Land 

Inactive/Passively Managed Forest 381 27% 8 <1% 

Grassland/Reverting Fields 4 <1% <1 <1% 

Scrub-Shrub 3 <1% <1 <1% 

Wetlands 86 6% <1 <1% 

Total: NON-DEVELOPED LAND 474 33% 10 <1% 

 

Total: Surface Water (Atmospheric) 40 3% 3 <1% 

 

TOTAL: DIRECT WATERSHED 1,417 100% 1,269 100% 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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Descriptive Land Use and Phosphorus Export Estimates

Agriculture: Agricultural land is estimated to comprise 679 acres (48%) of the watershed area 

including: non-manured hayland (9%), manured hayland (4%), row crops (26%), animal feedlot/

barnyard (1%) and pasture (8%). These agricultural land uses contribute nearly 1,218 kg (96%) of the 

total phosphorus loading to Daigle Pond. Animal feedlots/barnyards are the largest agricultural 

contributor, accounting for approximately 54% of the total phosphorus load to Daigle Pond. Row 

crops are also a large contributor, accounting for 32% of the load. These data were mapped using 

GIS software and verified by aerial photography and information from the St. John Valley Soil and 

Water Conservation District. 

Actively Managed Forest Land: The estimated operated forest land for the Daigle Pond direct 

watershed consists of 162 acres. This estimate is based on a GIS analysis of land uses and 

represents 12% of the total land area, contributing less than 1% of the total phosphorus load to Daigle 

Pond. While poorly managed forestry operations have the potential to negatively impact a waterbody 

through erosion and sedimentation from logging sites, properly managed forestry operations generally 

do not. Sustainable forest management can enhance water quality through sequestering excess 

nutrients, particularly in forested riparian areas. Harvested forest acres in Maine typically regenerate 

as forest, whether or not they are under any type of planned forest management or under the 

supervision of a Licensed Forester. 

Shoreline Development consists of all lands within the immediate shoreland area (250 feet) of Daigle 

Pond. This type of development can have a large total phosphorus loading impact in comparison to 

their relatively small percentage of the total land area in the watershed. This is not the case for Daigle 

Pond, given the sparse extent of shoreline development. There are approximately 11 houses 

(primarily year-round) along the Daigle Pond shoreline. Shoreline residential land use is estimated to 

consist of only 0.8% of the total watershed land area and contribute less than 1% of the total 

phosphorus load to Daigle Pond. 

Shoreline Roads: NPS pollution associated with 

shoreline roads (roads within 250 feet of the 

shoreline) can vary widely, depending upon road 

type, slope and proximity to a surface water 

resource. Total phosphorus loading from 

shoreline roads was estimated using GIS land 

use data to determine the overall area occupied 

by this category. The average width for shoreline 

roads in the Daigle Pond watershed was 

estimated to be about 22 meters for state-owned 

roads and 16 meters for town-owned roads 

(based on the findings from previous Maine lake 

PCAP reports). Based on these factors, shoreline 

roads were determined to cover about 6 acres and contribute less than 1% (5 kg/yr) of the total 

phosphorus load to the direct watershed. 

State-Owned Route 161 passes along the south side of 

Daigle Pond. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

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 Overall, shoreline development comprises just over 1% of the total watershed area and contributes 

approximately 8 kg of total phosphorus annually, accounting for less than 1% of the estimated 

phosphorus load. 

Non-Shoreline Development and Land Uses

Non-Shoreline Development consists of all lands outside the immediate shoreline of Daigle Pond - 

including public and private roads, low density residential areas and commercial/industrial areas. The 

total land area covered by these land-uses was calculated with GIS land use data. 

Roads: Road widths were estimated from previous PCAP reports and from on-screen viewing of 

aerial photography (private roads were estimated to be 6 meters average width) to determine the 

amount of total phosphorus loading from this land use category. Based on these factors, nonshoreline roads contribute an estimated 17 kg/year (~1%) of the total phosphorus load to Daigle 

Pond’s direct watershed. 

Low Density Residential: Low density residential land use consists of approximately 22 acres and 

contributes an estimated 6 kg/year (< 1%) of the total phosphorus loading to the Daigle Pond direct 

watershed. 

Phosphorus Loading from Non-Developed Lands and Water

Inactive/Passively Managed Forests: Of the total non-developed land area within the Daigle Pond 

watershed, 381 acres are forested, characterized by privately-owned non-managed deciduous and 

mixed forest plots. Less than 1% of the phosphorus load (8 kg/year) is estimated to be derived from 

non-commercial forested areas within Daigle Pond’s direct drainage area. 

Other Non-Developed Land Areas: Combined wetlands, grasslands/reverting fields and scrubshrub account for approximately 6% of the remaining land area and less than 1% of the total 

phosphorus export load. 

Atmospheric Deposition (Open Water): Surface waters for Daigle Pond’s direct watershed comprise 

3% of the total land area (40 acres) and account for an estimated 3 kg of total phosphorus per year, 

representing less than 1% of the total direct watershed load entering Daigle Pond. The total 

phosphorus loading coefficient chosen (0.16 kg/ha) is similar to that used for central Maine lakes in 

Kennebec County. This value represents the median of a range of values from Reckhow (1980) of 

0.11 kg/ha to 0.21 kg/ha. The upper range generally reflects a watershed that is 50 percent forested, 

combined with agricultural areas interspersed with urban/suburban land use. 

• To convert kilograms (kg) of total 

phosphorus to pounds - multiply 

by 2.2046 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

16 

PHOSPHORUS LOADS – Watershed, Sediment and In-Lake Capacity 

 Supporting documentation for the phosphorus loading analysis includes water quality monitoring 

data from Maine DEP and the Volunteer Lake Monitoring Program, and the development of a 

phosphorus retention model (see Appendices, p.21, for detailed information). Please note that two 

methods were used in our total phosphorus loading analysis to assist with the preparation of this 

report: 1) a GIS-based model to provide a relative estimation of impacts from watershed land uses for 

the development of phosphorus reduction strategies by stakeholders; and 2) an in-lake phosphorus 

concentration model to determine the phosphorus reduction needed for the Daigle Pond TMDL. 

These two methods may yield different overall phosphorus loading results depending on the available 

water quality data and particular characteristics of the watersheds and water bodies being modeled.

1. GIS-Based Land Use and Indirect Load Method 

Watershed Land Uses: Total phosphorus loadings to Daigle Pond originate from a combination of 

external watershed and internal lake sediment sources. Watershed total phosphorus sources, totaling 

approximately 1,269 kg annually (corrected GIS) have been identified and accounted for by land use 

(See Table 2 - page 25). Internal lake sediment P-loadings of 26 kg were estimated to be present 

during the 1995 growing season (only suitable year of record). In light of relatively high measures of 

TP in the water column, this is probably a gross under-estimate of the actual sediment phosphorus 

load in Daigle Pond (personal communication, Roy Bouchard 2006). 

2. In-Lake Concentration Method (TMDL) 

Pond Capacity: The assimilative capacity for all existing and future non-point pollution sources for 

Daigle Pond is 116 kg of total phosphorus per year, based on a target goal of 16 ppb (See 

Phosphorus Retention Model - page 29). 

 

Target Goal: A change in 1 ppb in phosphorus concentration in Daigle Pond is equivalent to 7.3 kg. 

The difference between the target goal of 16 ppb and the measured average summertime total 

phosphorus concentration (50 ppb or 365 kg) is 34 ppb or 248 kg (34 x 7.3). 

Future Development: The annual total phosphorus contribution to account for future development 

for Daigle Pond is 3.65 kg (0.50 x 7.3) (see page 28). 

Reduction Needed: Given the target goal and a 3.65 kg allocation for future development, the total 

amount of phosphorus needed to be reduced, on an annual basis, to restore water quality standards 

in Daigle Pond approximates 252 kg (248 + 3.65). 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

17 

PHOSPHORUS CONTROL ACTION PLAN

Recent and Current NPS/BMP Efforts 

 The St. John Valley SWCD, the Aroostook County– St. John Valley Natural Resources 

Conservation Service (NRCS), and local residents have long recognized the need for reducing NPS 

pollution to Daigle Pond. 

 In the early 1990’s, in an effort to address water quality concerns, local residents formed the Daigle 

Pond restoration Committee. In 1997, the group was awarded Environmental Protection Agency 

(EPA) Section 319 funding to implement erosion control practices in the watershed. Between 1997 

and 2002, the Committee, in conjunction with the SJV-SWCD, the Natural Resources Conservation 

Service, the Town of New Canada, the Maine Forest Service, and other agencies worked on several 

erosion control projects throughout the watershed. These included planting a vegetative buffer around 

the northern perimeter of the pond and installing multiple driveway projects. Additionally, a new 

concrete dam outlet was constructed, and the causeway culvert separating the two basins was 

repaired. Finally, a modified Nutrient and Sediment Control System (NSCS) was installed on local 

cropland to reduce soil loss. This is one of many agricultural BMPs that have been installed in the 

Daigle Pond watershed. 

 The Aroostook County– St. John Valley Natural Resources Conservation Service (NRCS) has an 

ongoing relationship with land owners in the Daigle Pond watershed and has helped them establish 

voluntary conservation management plans to reduce nutrient export from agricultural operations. 

Between 1990 and 2004, seventeen erosion control and nutrient management projects were 

completed on a local cattle farm, including the construction of a waste storage structure, heavy use 

area protection, and a riparian forest buffer, among others. 

 Several BMPs have also been installed along state-owned roads in the watershed. In the early 

1990’s, Maine Route 161 ditches were unstable and washed plumes of soil into Daigle Pond each 

year. This erosion problem contributed to sedimentation in Daigle Pond. However, in 1994-1995, 

several BMPs were installed, thus eliminating this major source of soil materials to the pond (Maine 

NPS Control Program). Additionally, between 1992 and 2003, 12 septic systems in the Daigle Pond 

watershed were replaced with funding from the Maine Department of Environmental Protection. 

 Continued efforts for installing BMPs and reducing NPS pollution in the Daigle Pond watershed are 

imperative given the current poor water quality conditions. Due to a buildup of sediment in the pond 

over the years, Daigle Pond is still influenced by historical land management practices in the 

watershed, and new phosphorus is introduced each year (Bouchard 1996). A continued reduction in 

nonpoint inputs to Daigle Pond, primarily through animal grazing and feedlot BMP installation and 

proper maintenance, is crucial to achieving suitable long-term water quality. 

Construction of a stable, 

concrete dam outlet and 

repairs to a deteriorating 

causeway culvert served to 

decrease bank erosion, 

restore historic water levels, and improve fish habitat in Daigle Pond. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

18 

Recommendations for Future NPS/BMP Work 

 Daigle Pond has impaired water quality primarily due to historical high phosphorus inputs from 

nonpoint source (NPS) pollution and resultant internal lake sediment recycling of phosphorus. 

Specific recommendations regarding recent and current efforts in the watershed, Best Management 

Practices (BMPs), and actions to reduce (1) external watershed and (2) accumulated bottom sediment 

total phosphorus loadings in order to improve water quality conditions in Daigle Pond are as follows: 

Watershed Management: Several agencies (i.e., Maine DEP, SJV-SWCD, USDA/NRCS) have been 

involved in attempting to restore the water quality of Daigle Pond. This PCAP-TMDL report will serve 

as a compilation of existing information about the past and present restoration projects that have been 

undertaken in order to adequately assess future NPS BMP needs in the watershed.

Agriculture: Agricultural land encompass the greatest land area of the land-uses in the watershed, 

and contributes the greatest phosphorus load. BMP recommendations for agricultural land uses 

include providing education on grazing conservation practices and feedlot planning assistance. The 

Natural Resources Conservation Service provides technical assistance for using proper agricultural 

BMPs. For more information contact the NRCS office in Aroostook County (207-834-3311). 

Shoreline Residential: Densely developed residential dwellings have the potential to negatively 

effect water quality. An effort should be undertaken to encourage landowners to follow Land Use 

Regulation Commission (LURC) standards for maintaining adequate and effective vegetated shoreline 

buffers. For a copy of The Buffer Handbook, contact Maine DEP’s Bureau of Land & Water Quality in 

Augusta (287-2112) or for technical assistance, contact the SJV-SWCD at 834-6435.

Action Item # 3: Educate watershed citizens about shoreline buffers 

Activity

Develop a Buffer Awareness Campaign 

Participants

Maine DEP, LURC, SJV-SWCD, 

Towns of New Canada and Fort 

Kent, interested watershed citizens. 

Schedule & Cost

Begin immediately - 

$1,500/yr 

Action Item #1 : Coordinate existing watershed management efforts 

Activity

Initiate efforts to develop a Daigle Pond 

Advisory Team 

Participants

SJV-SWCD, NRCS, Maine DEP, 

interested watershed citizens—

stakeholders. 

Schedule & Cost

Annual roundtable meetings—

beginning in summer 2006—

minimal cost 

Action Item # 2: Conduct workshops for agricultural landowners 

Activity

Conduct workshops encouraging the use 

of phosphorus control measures within 

the Daigle Pond watershed. 

Update, inspect, and maintain installed 

BMPs in the watershed. 

Participants

SJV-SWCD, NRCS, agricultural 

landowners and watershed 

municipalities (Fort Kent and New 

Canada). 

Schedule & Cost

Annually beginning in 2006 

Variable cost depending on 

type of activities. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

19 

Roadways: A common cause of NPS pollution in lake/pond watersheds is often related to roads, 

which if not properly designed and maintained can be a major source of erosion and sedimentation 

into ponds, lakes and streams. This PCAP report estimates that public and private roads combined 

contribute approximately 2% of the total phosphorus load per year to Daigle Pond. As such, efforts 

should be undertaken to identify pollution sources from roads so that appropriate BMPs can be 

designed and installed to remediate problem areas. 

Septic Systems: Older, poorly designed and installed septic systems may contribute significantly to 

water quality problems, adding to the cumulative phosphorus load to Daigle Pond. While Daigle Pond 

septic systems – when properly sited, constructed, maintained, and set back from the water – should 

not affect water quality, many septic systems may not meet all of these criteria and thus have the 

potential to contribute phosphorus and other contaminants to lake water. Examples include septic 

systems sited in coarse, sandy soils with minimal filtering capacity, as well as soils that are shallow to 

bedrock., as well as older septic systems which pre-date Maine’s 1974 Plumbing Code. Approximately 

589 acres of the soils in the Daigle watershed have a low to very low suitability for development. 

Daigle watershed residents who believe they may have problems with their septic systems are 

encouraged to contact Maine-DEP for possible technical and/or financial assistance. 

Individual Action: All watershed residents should be encouraged through continued education and 

outreach efforts, including: retention or planting of natural vegetation of buffer strips, use of nonphosphate cleaning detergents, elimination of phosphorus-containing fertilizers, adequate 

maintenance of septic systems.

Municipal Action: Should include ensuring public compliance with local and state water quality laws 

and ordinances (Shoreland Zoning, Erosion and Sedimentation Control Law, plumbing code) through 

education and enforcement action, when necessary. Municipalities can also provide stormwater 

management education for local homeowners and businesses (see Action Item #6). 

Action Item # 4: Implement roadway best management practices 

Activity

Conduct survey of public and private 

roads in watershed to determine NPS 

pollution sources and establish/

implement roadway BMPs. 

Participants

Maine DEP, SJV-SWCD, Towns of 

Fort Kent and New Canada, 

interested watershed citizens. 

Schedule & Cost

2006-2007 

$1,000 - Approximately 617 

acres (1 sq. mi.) of the soils in 

the Daigle watershed have a 

low to very low suitability for 

development. 

Action Item # 5: Develop septic/sewage system inspection program 

Activity

Conduct septic/sewage system 

inspections to identify any potential 

malfunctions and promote regular 

pumping to ensure proper operation 

Participants

Maine DEP, SJV-SWCD, and 

watershed citizens. 

Schedule & Cost

Annually beginning in 2006 

$1,500/yr 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

20 

 

 An MACD field visit in July of 2006 noted low flow from the Daigle Pond upper basin to the lower 

basin through a single culvert crossing under Martin Road. Likewise, the culverts connecting the 

lower basin to the outflow dam also appeared to be restricting flow. ME-DEP staff agreed that the 

current conditions may not be reflective of the high flushing rates calculated for the pond, and that this 

should be a point of further investigation. Lower flushing rates caused by the culvert restrictions may 

be leading to higher than normal phosphorus retention that would normally be flushed naturally from 

the system. 

 

WATER QUALITY MONITORING PLAN

 Historically, the water quality of Daigle Pond has been monitored via measures of Secchi disk 

transparencies during the open water months since 1977 (Maine DEP and VLMP). Continued longterm water quality monitoring (water transparencies) for Daigle Pond will be conducted monthly, from 

May to October, through the continued efforts of Maine DEP and VLMP. Under this planned, postTMDL water quality-monitoring plan, sufficient data will be acquired to adequately track seasonal and 

inter-annual variation and long-term trends in water quality in Daigle Pond. A post-TMDL adaptive 

management status report will be prepared 5 to 10 years following EPA approval. 

PCAP CLOSING STATEMENT

 The Maine Association of Conservation Districts and the Saint John Valley Soil and Water 

Conservation District, in cooperation with lake stakeholders, have initiated the process of addressing 

nonpoint source pollution in the Daigle Pond watershed. Technical assistance by SJV-SWCD is 

available to both watershed towns (New Canada and Fort Kent) to mitigate phosphorus export from 

existing NPS pollution sources and to prevent excess loading from future sources. It is critical that the 

towns of New Canada and Fort Kent recognize the inherent value of Daigle Pond and its vital link to 

the community by providing strong support to restoration efforts. Both towns should cooperate with 

the SJV-SWCD and NRCS in the pursuit of local and regional lake protection and improvement 

strategies. This teamwork approach should result in an eventual and overall improvement in Daigle 

Pond through NPS-BMP implementation and increased public involvement and awareness. 

Activity

Study the hydrology of the two basins 

and the potential need for additional culverts to increase flow. 

Participants

Maine DEP, SJV-SWCD, Towns of 

Fort Kent and New Canada. 

Schedule & Cost

Begin immediately— 

$3,000 

 Action Item # 7: Investigate the hydrology of the upper and lower basins. 

Activity

Provide stormwater management 

education to. Home owners, small business owners, and industrial facilities in 

the 

Participants

Maine DEP, SJV-SWCD, Towns of 

Fort Kent and New Canada. 

Schedule & Cost

Begin immediately— 

$2,000 

 Action Item # 6: Expand homeowner education & technical assistance programs
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

21 

APPENDICES 

DAIGLE POND (New Canada) 

Total Maximum Daily (Annual Phosphorus) Load 

 Introduction to Maine Lake TMDLs and PCAPs ...................................... 22 

 Water Quality, Priority Ranking, and Algae Bloom History ....................... 23 

 Natural Environmental Background Levels ........................................... 23 

 Water Quality Standards and Target Goals .......................................... 23-24 

 Estimated Phosphorus Export by Land Use Class (Table 2) .................... 24-27 

 Linking Water Quality and Pollutant Sources ........................................ 28 

 Future Development................................................................... 28 

 Internal Lake Sediment Phosphorus Mass ...................................... 28 

 Total Phosphorus Retention Model................................................ 29 

 Load (LA) and Wasteload (WLA) Allocations .................................... 29-30 

 Margin of Safety and Seasonal Variation......................................... 30 

Daily TP Pollutant Load Calculations for Daigle Pond.........................31

 Public Participation ......................................................................... 33 

 Stakeholder and Public Review Process and Comments ........................ 33-34 

 Literature - Lake Specific and General References ................................ 35-40 

_____________________________________________________ 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

22 

Maine Lake TMDLs and Phosphorus Control Action Plans (PCAPs) 

You may be wondering what the acronym 'TMDL' represents and what it is all about. TMDL is 

actually short for 'Total Maximum Daily Load’ as historically applied to point-source pollutants. This 

information, no doubt, does little to clarify TMDLs in most people's minds. However, when we think of 

this as an annual phosphorus load (Annual Total Phosphorus Load), it begins to make more sense, for 

nonpoint source pollution. Following EPA guidance (Spring 2006), we now report both daily and 

annual total phosphorus loads. 

Simply stated, excess nutrients or phosphorus in lakes promote nuisance algae growth/blooms - 

resulting in the violation of water quality standards as measured by water clarity depths of less than 2 

meters. A lake TMDL is prepared to estimate the total amount of total phosphorus that a lake can 

accept on an annual basis without harming water quality. Historically, development of TMDLs was 

first mandated by the Clean Water Act in 1972, and was applied primarily to point sources of water 

pollution. As a result of public pressure to further clean up water bodies, lake and stream TMDLs are 

now being prepared for watershed-generated Non-Point Sources (NPS) of pollution. 

Nutrient enrichment of lakes through excess total phosphorus originating from watershed soil 

erosion has been generally recognized as the primary source of NPS pollution. Major land use 

activities contributing to the external phosphorus load in lakes include residential-commercial 

developments, roadways, agriculture, and commercial forestry. Statewide, there are 32 lakes in 

Maine which do not meet water quality standards due to excessive amounts of in-lake total 

phosphorus - the great majority of which are located in south-central Maine. 

The first Maine lake TMDL was developed (1995) for Cobbossee Lake by the Cobbossee Watershed 

District (CWD) - under contract with Maine DEP and U.S. EPA. Recently (June 2006), Cobbossee 

Lake was officially removed from the TMDL listing of “impaired” waterbodies, in light of 8 years of 

above standard water clarity measures. TMDLs have been approved by U.S. EPA for Madawaska 

Lake (Aroostook County), Sebasticook Lake, East Pond (Belgrade Lakes), China Lake, Webber, 

Threemile and Threecornered ponds (Kennebec County), Mousam Lake, the Highland lakes in 

Falmouth and Bridgton, Annabessacook Lake, Pleasant Pond, Upper Narrows Pond and Little 

Cobbossee Lake (under contract with CWD), Sabattus, Toothaker, and Unity ponds and Long Lake 

(with assistance from Lakes Environmental Association), Togus Pond, Duckpuddle Pond, Lovejoy 

Pond, Lilly Pond, and Sewall Pond. PCAP-TMDLs are presently being prepared by Maine DEP, with 

assistance from the Maine Association of Conservation Districts (MACD) and County Soil and Water 

Conservation Districts (SWCD’s) - for Hermon and Hammond Ponds, and Cross Lake. PCAP-TMDL 

studies have also been initiated for Trafton Lake, as well as several other remaining 2004 303(d) listed 

PCAP-TMDL waterbodies in Aroostook County. 

Lake PCAP-TMDL reports are based in part on available water quality data, including seasonal 

measures of total phosphorus, chlorophyll-a, Secchi disk transparencies, and dissolved oxygen-water 

temperature profiles. Actual reports include: a lake description; watershed GIS assessment and 

estimation of NPS pollutant sources; selection of a total phosphorus target goal (acceptable amount); 

allocation of watershed/land-use phosphorus loadings, and a public participation component to allow 

for stakeholder review. 

PCAP-TMDLs are important tools for maintaining and protecting acceptable lake water quality and 

are designed to 'get a handle' on the magnitude of the NPS pollution problem and to develop plans for 

implementing Best Management Practices (BMPs) to effectively address the lake’s water pollution 

problem. Landowners and watershed groups are eligible to receive technical and financial assistance 

from state and federal natural resource agencies to reduce watershed total phosphorus loadings to 

the lake. Note: for non-stormwater regulated lake watersheds, the development of phosphorus-based 

lake PCAP-TMDLs are not generally intended by Maine DEP to be used for regulatory purposes. 

_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 

 For further information, contact Dave Halliwell, Maine Department of Environmental Protection, 

Lakes PCAP-TMDL Program Manager, SHS #17, Augusta, ME 04333 (207-287-7649). 

E-mail: david.halliwell@maine.gov
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

23 

Water Quality, Priority Ranking, and Algae Bloom History 

Water Quality Monitoring: (Source: Maine DEP and VLMP 2005) Water quality monitoring data for 

Daigle Pond (station 1, deep hole, east basin) has been collected since 1977 (77, 80, 89, 95, 98, 03- 

05). Hence, this present water quality assessment is based on seven years of water quality data 

including 8 years of Secchi disk transparency (SDT) measures, combined with 4 years of epilimnion 

core total phosphorus (TP) data, 5 years of water chemistry and 5 years of chlorophyll-a measures. 

Water Quality Measures: (Source: 

Maine DEP and VLMP 2005) Historically, 

Daigle Pond has had a range of SDT 

measures from 1.0 to 2.1 m, with an 

average of 1.6 m; an epilimnion core TP 

range of 23 to 162 with an average of 97 

parts per billion (ppb), and chlorophyll-a 

measures ranging from 16 to 132 ppb, 

with an average of 53.1 ppb. Due to 

shallow depth, Daigle Pond does not 

thermally stratify in the summer. As such, 

recent dissolved oxygen (DO) profiles 

show little DO depletion in deep areas of 

the pond. While late summer dissolved 

oxygen levels in 2003 showed a slight 

improvement since the late 1990’s, about 

70% of the water column was unsuitable 

for fish in contrast to 50% in 1980. The 

potential for total phosphorus to leave the 

bottom sediments and become available to algae in the water column (internal loading) is low based 

on recent oxygen profiles (Maine DEP 2005). However, it is believed that bottom sediments are a 

source of high phosphorus in the pond, especially during warmwater months (Bouchard 2006).

Priority Ranking, Pollutant of Concern and Algae Bloom History: Daigle Pond is listed on the 

State's 2004 303(d) list of waters in non-attainment of Maine State water quality standards and was 

moved up in the priority development order due to the need to complete an accelerated approach to 

lakes TMDL development. This Daigle Pond TMDL has been developed for total phosphorus, the 

major limiting nutrient to algae growth in freshwater lakes in Maine. 

 As indicated by the chart above, the water quality of Daigle Pond has generally been poor during 

the entire historical monitoring period, and has somewhat improved since 1998. However, since 

sampling began in 1977, minimum transparencies have never met the state's water quality limit of two 

meters. Consequently, summertime nuisance algal blooms have been a regular occurrence. 

 

Natural Environmental Background levels for Daigle Pond were not separated from the total nonpoint source load because of the limited and general nature of available information. Without more 

and detailed site-specific information on non-point source loading, it is very difficult to separate natural 

background from the total non-point source load (US-EPA 1999). There are no known point sources 

of pollutants to Daigle Pond.

WATER QUALITY STANDARDS & TARGET GOALS

Maine State Water Quality Standard for nutrients which are narrative, are as follows (July 1994 

Maine Revised Statutes Title 38, Article 4-A): “Great Ponds Class A (GPA) waters shall have a stable 

or decreasing trophic state (based on appropriate measures, e.g., total phosphorus, chlorophyll-a, 

Daigle Pond Historical Water Clarity

0

1

2

3

4

1977 1980 1989 1995 1998 1999 2003

Meters Below Surface

Daigle Pond Min. Transparency DEP Standard Trend

 Daigle Pond minimum water clarity declined from 1980 to 1998. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

24 

Secchi disk transparency) subject only to natural fluctuations, and be free of culturally induced algae 

blooms which impair their potential use and enjoyment.” 

 

 Maine DEP’s functional definition of nuisance algae blooms include episodic occurrence of Secchi 

disk transparencies (SDTs) < 2 meters for lakes with low levels of apparent color (<30 SPU) and for 

higher color lakes where low SDT readings are accompanied by elevated chlorophyll a levels (>8 

ppb). Daigle Pond is a colored lake (average color 63 SPUs), with low late summer SDT readings 

(annual average of 1.6 meters), in association with high chlorophyll-a levels (53.1 ppb late summer 

average). Currently, Daigle Pond does not meet water quality standards primarily due to nonattainment of water transparency measures over time. This water quality assessment uses historic 

documented conditions as the primary basis for comparison. 

Designated Uses and Antidegradation Policy: Daigle Pond is designated as a GPA (Great Pond 

Class A) water in the Maine DEP state water quality regulations. Designated uses for GPA waters in

general include: water supply; primary/secondary contact recreation (swimming and fishing); hydroelectric power generation; navigation; and fish and wildlife habitat. No change of land use in the 

watershed of a Class GPA water body may, by itself or in combination with other activities, cause 

water quality degradation that would impair designated uses of downstream GPA waters or cause an 

increase in their trophic state. Maine's anti-degradation policy requires that "existing in-stream water 

uses, and the level of water quality necessary to sustain those uses, must be maintained and 

protected." 

Numeric Water Quality Target: The numeric (in-lake) water quality target for Daigle Pond is set at 

16 ppb total phosphorus (116 kg/yr). Since numeric criteria for phosphorus do not exist in Maine's 

state water quality regulations - and would be less accurate targets than those derived from this study 

- we employed best professional judgment to select a target in-lake total phosphorus concentration 

that would attain the narrative water quality standard. Spring-time (late May - June) total phosphorus 

levels in Daigle Pond historically averaged 36 ppb, while summertime levels averaged 50 ppb. 

 In summary, the numeric water quality target goal of 16 ppb for total phosphorus in Daigle Pond 

was based on observed late spring - early summer pre-water column stratification measures, generally 

corresponding to non-bloom conditions, as reflected in suitable (water quality attainment) measures of 

both Secchi disk transparency (> 2.0 meters) and chlorophyll-a (< 8.0 ppb). 

 

 Notably, the development of the Daigle Pond TMDL (DEPLW 2006-0789) and selection of a 

numeric water quality target of 16 ppb total phosphorus is protective of downstream uses in Daigle 

Brook, which is also water quality impaired and 303(d) listed. The water quality impairment of Daigle 

Brook is due to dissolved oxygen loss related to primary productivity caused by excessive pollutants 

(total phosphorus) from Daigle Pond and the brook's direct watershed within the Cross Lake drainage 

system. The planned reduction of total phosphorus loading to Daigle Brook (a primary nutrient source 

for downstream Cross Lake) coupled with the attainment of the in-lake target of 16 ppb in Daigle Pond 

will provide for attainment and maintenance of water quality standards in the brook. Following final 

EPA approval of the Daigle Pond and Cross Lake TMDL (DEPLW 2006-0790), Daigle Brook will be redesignated from the 303(d) list to category 4A (TMDL approved). 

ESTIMATED PHOSPHORUS EXPORT BY LAND USE CLASS 

 Table 2 details the numerical data used to determine external phosphorus loading for the Daigle 

Pond watershed. The key below Table 2 on the next page explains the columns and the narrative that 

follows (page 26) relative to each of the representative land use classes. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

25 

Key for Columns in Table 2

Land Use Class: The land use category that was analyzed for this report 

Land Area in Acres: The area of each land use as determined by GIS mapping and aerial photography. 

Land Area %: The percentage of the watershed covered by the land use. 

TP Coeff. Range kg/ha: The range of the total phosphorus coefficient values listed in the literature associated with the corresponding land 

use. 

TP Coeff. Value kg/ha: The selected coefficient for each land use category. The total phosphorus coefficient is determined from previous 

research – usually the median value, if listed by the author. The coefficient is often adjusted using best professional judgment based on 

conditions including soil type, slope, and best management practices (BMPs) installed. 

Land Area in Hectares: Conversion, 1.0 acre = 0.404 hectares 

TP Export Load kg P: The GIS adjusted TP Export Load, accounting for soils and slope and based on total hectares x the applicable 

total phosphorus coefficient. 

TP Export Total %: The percentage of estimated phosphorus exported by the land use. 

Table 2. Daigle Pond Direct Watershed - Estimated Phosphorus Export by Land Use 

 Land Land TP Coeff. TP Coeff. Land TP TP Export 

LAND USE CLASS Area Area Range Value Area Export 

Load Total 

 Acres % kg TP/ha kg TP/ha Hectares Kg TP/ha % 

 

Agricultural Land 

Hayland (non-manured) 131 9% 0.35-1.34 0.64 53 42 3% 

Hayland (manured) 60 4% 0.35-1.34 1.51 24 44 4% 

Row Crops 367 26% 0.26-18.6 2.24 149 407 32% 

Animal Feedlot/Barnyard 13 1% 21-795 103 5 681 54% 

Pasture (Grazed Meadows) 108 8% .14-4.9 0.81 44 44 3% 

Sub-Totals 679 48% 275 1,218 96% 

 

Actively Managed Forest 162 12% 0.04-0.6 0.08 66 7 0.5% 

Sub-Totals 162 12% 66 7 0.5% 

 

Shoreline Development 

Low Density Residential 11 0.8% 0.25 - 1.75 0.5 5 3 0.2% 

Roads 6 0.4% 0.60 - 10.0 2 2 5 0.4% 

Sub-Totals 17 1% 7 8 0.6% 

 

Non-Shoreline Development 

Roads 23 1.6% 0.60 - 10.0 1.5 9 17 1.4% 

Low Density Residential 22 1.5% 0.25 - 1.75 0.5 9 6 0.4% 

Sub-Totals 45 3% 18 23 1.8% 

 

Total: DEVELOPED LAND 903 64% 366 1,256 99% 

 

Non-Developed Land 

Inactive/Passively Managed Forest 381 27% 0.01-0.08 0.04 154 8 0.63% 

Grassland/Reverting Fields 4 0.3% 0.1 - 0.2 0.2 1 0.3 0.02% 

Scrub-Shrub 3 0.2% 0.1 - 0.2 0.15 1 0.2 0.02% 

Wetlands 86 6% 0-0.05 0.01 35 0.4 0.03% 

Total: NON-DEVELOPED LAND 474 33% 192 10 0.7% 

 

Total: Surface Water (Atmospheric) 40 3% 0.11-0.21 0.16 16 3 0.2% 

 

TOTAL: DIRECT WATERSHED 1,417 100% 574 1,269 100% 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

26 

Total Phosphorus Land Use Loads

 Estimates of total phosphorus export from different land uses found in the Daigle Pond watershed 

as presented on the previous page in Table 2 represent the extent of the current direct watershed

phosphorus loading to the lake (1,269 kg/yr). 

 Total phosphorus loading measures are provided as a range of values to reflect the degree of 

uncertainty generally associated with such relative estimates (Walker 2000). The watershed total 

phosphorus loading values were primarily determined using literature and locally-derived export 

coefficients as found in Schroeder (1979), Reckhow et al. (1980), Dennis (1986), Dennis et al. (1992), 

and Bouchard et al. (1995) for residential properties, roadways, agriculture and other types of land 

uses. 

Agriculture: Phosphorus loading coefficients as applied to agricultural land uses were adopted from: 

Dennis and Sage (1981): manured hayland (1.51 kg/ha/yr), non-manured hayland (0.64 kg/ha/yr), 

Reckhow et al. (1980): animal feedlot/barnyard (103 kg TP/ha/yr)*, pasture/grazed meadow (0.81 kg 

TP/ha/yr), and row crops/tillage/cultivation (2.24 kg TP/ha/yr). 

 *The land use coefficient used in previous TMDL’s for animal feedlot/barnyards (224 kg TP/ha/yr) is 

the median of a range of coefficients (21-795 kg TP/ha/yr) adopted from Reckhow et al. (1980). Using 

the EPA-STEPL model, this feedlot/barnyard coefficient was adjusted for this report based on 

documented information about previously installed BMPs obtained from the SJV-SWCD in conjunction 

with the USDA/NRCS. The EPA-STEPL model calculates phosphorus delivery from animal feedlots 

using a variety of inputs including annual rainfall, contributing land area, percent paved area, number 

and types of animals, manure application rates, soils, and types of installed BMPs. The resulting 

coefficient of 103 kg/ha/yr assumes that all BMPs are functional and properly maintained. It is 

important to note that even using the lowest coefficient in the range of feedlot/barnyard coefficients 

(21kg/ha/yr) results in significant loading to Daigle Pond. 

Actively Managed Forest Land: The phosphorus loading coefficient applied to actively managed 

forest land (0.08 kg/ha/yr) was changed beginning with the Long Lake PCAP-TMDL report following 

consultation with Lakes Environment Association and Maine Forest Service staff. The rationale for 

this change was based on the fact that properly managed harvest areas will generally act as 

phosphorus sinks during periods of regeneration. According to the Maine Forest Service, of the nearly 

3,500 water quality inspections conducted throughout the state in 2003, approximately 7% of the 

harvested sites posed “unacceptable” risks to water quality. 

 PCAP-TMDL reports prior to the Long Lake report identified a “worst case” upper limit phosphorus 

loading coefficient of 0.6 kg/ha/yr for operated forestland. Therefore, for any given watershed in 

Maine we determined that applying this “worst case” coefficient to 7% of operated forest land while 

applying the “best case” coefficient (0.04 kg/ha/yr) to the remaining operated forest land would provide 

a relatively accurate estimate of total phosphorus loading from operated forest land. Combining worst 

case and best case coefficients yields the new phosphorus loading coefficient for operated forest land 

of 0.08 kg/ha/yr [(0.07 x 0.6) + (0.93 x 0.04)]. 

Residential Development: The range of phosphorus loading coefficients used for low density 

residential, including seasonal camps (0.25 – 1.75 kg/ha/yr) was developed from information on 

residential lot stormwater export of phosphorus as derived from Dennis et al (1992), and first 

implemented in the 1995 Cobbossee Lake TMDL. Phosphorus loading coefficients for low density 

residential development was estimated to be 0.50 kg/ha/yr. 

Private and Public Roads: The total phosphorus loading coefficient for private/camp and public 

roads (2.0 kg/ha/yr for private/camp roads and 1.5 kg/ha/yr for public roads) was chosen, in part, from 

previous studies of rural Maine highways (Dudley et al. 1997) and phosphorus research by Jeff 

Dennis (Maine DEP). 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

27 

Total Developed Lands Phosphorus Loading: A total of 99% (1,256 kg) of the phosphorus loading 

to Daigle Pond is estimated to have been derived from the cumulative effect of the preceding cultural 

land use classes: agriculture (96% - 1,218 kg); shoreline development (<1% - 8 kg); and non-shoreline 

development 1.8% - 23 kg) as depicted in Table 2. 

Non-Developed Lands Phosphorus Loading: The phosphorus export coefficient for inactive/

passively managed forest land (0.04 kg/ha/yr) is based on a New England regional study (Likens et al 

1977) and phosphorus availability recommendation by Jeff Dennis (Maine DEP). The phosphorus 

export coefficient for grassland/reverting fields (0.20 kg/ha/yr) and scrub/shrub (0.10 kg/ha/yr) is 

based on research by Bouchard in 1995 (0.20 kg/ha/yr). The export coefficient for wetlands is based 

on research by Bouchard 1995 and Monagle 1995 (0.01 kg/ha/yr). The phosphorus loading coefficient 

chosen for surface waters (atmospheric deposition -0.16 kg/ha/yr), was originally used in the China 

Lake TMDL (Kennebec County), and subsequent PCAP-TMDL lake studies in Maine. 

Shoreline Erosion: Undeveloped areas of the lake shoreline that may be eroding due to natural 

causes (i.e., wind, wave and ice action) are not included as a source of phosphorus due to the 

difficulty in quantifying impact area and assigning suitable phosphorus loading coefficients. 

Phosphorus Load Summary

 It is our professional opinion that the selected export coefficients are appropriate for the Daigle 

Pond watershed. Results of the land use analysis indicate that a best estimate of the present total 

phosphorus loading from external nonpoint source nutrient pollution approximates 1,269 kg/yr. 

LINKING WATER QUALITY and POLLUTANT SOURCES 

Annual/Daily Load Capacity: Total Phosphorus (TP) serves as a surrogate measure of Maine’s 

narrative water quality standards for lake trophic status. The TP TMDL is originally calculated as an 

annual load (kg TP/yr), which is based on an in-lake numeric water quality target (ppb or ug/l TP) and 

the annual flushing rate of the lake, using generally accepted response models for lakes. It is 

appropriate and justifiable to express the Daigle Pond TMDL as a monthly load even though the pond 

has an annual flushing rate of 21.3 (see discussion below and seasonal variation narrative on page 

30). The annual flushing rate, or the theoretical rate at which water in a lake is replaced on an annual 

basis, is calculated as:

 

# Flushes/year = (Watershed area * Runoff/year) / Lake volume 

 This TMDL also presents daily pollutant loads of TP in addition to the annual load. Daily flushing 

rates were determined by first calculating the monthly discharge from Dudley (2004). A number of 

parameters were required for input into these formulas including: Drainage area; % of significant sand 

and gravel aquifers; distance from the watershed to a predetermined line off the Maine coast; and 

mean annual precipitation. These parameters were determined using GIS (ArcMap 8.3).

Once the monthly discharge was determined, this information was used to ascertain the following: 

 % Total Monthly Discharge = (Total monthly discharge/ Total annual discharge) *100 

 # Flushes/month = (Total # of flushes/year * % of total monthly discharge) 

 # Flushes/day = (Flushes/month)/(Days/month) 

 The majority of the parameters used for calculating the annual loading capacity (kg TP/yr) on page 

29 (Dillon and Rigler 1974, where L= (Azp)/(1-R)), remain unchanged for use in calculating the daily 

loading capacity. The exception is p, where p now equals flushes/month. Thus, the monthly loading 

capacity is expressed as a proportion of the annual loading capacity, based on the discharge 

expected for that month. The daily loading capacity was then calculated as follows: 

Daily Loading Capacity (kg/day) = (Monthly Load Capacity)/(Days/month) 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

28 

The daily loads for Daigle Pond are presented on page 31. 

Assimilative Loading Capacity: The Daigle Pond basin lake assimilative capacity is capped at 116 

kg TP/yr, as derived from the empirical phosphorus retention model based on a target goal of 16 ppb. 

This value reflects the modeled phosphorus loading responsible for current trophic state conditions, 

based on a long term goal of maintaining average phosphorus concentrations at or below 16 ppb. 

This TMDL target concentration is expected to be met at all times (daily, monthly, seasonally, and 

annually). However, because the annual load of TP as a TMDL target is more easily aligned with the 

design of best management practices used to implement nonpoint source and stormwater TMDLs for 

lakes than daily loads of specific pollutants, this TMDL report recommends that the annual load target 

in the TMDL be used to guide implementation efforts. Ultimate compliance with water quality 

standards for the TMDL will be determined by measuring in-lake water quality to determine when 

standards are attained.

Future Development: The Maine DEP water quality goal of maintaining a stable trophic state 

includes a reduction of current P-loading which accounts for both recent P-loading as well as potential 

future development in the watershed. The methods used by Maine DEP to estimate future growth 

(Dennis et al. 1992) are inherently conservative, as they provide for relatively high-end regional growth 

estimates and largely non-mitigated P-export from new development. This provides an additional nonquantified margin of safety to ensure the attainment of state water quality goals. Previously 

unaccounted P-loading from anticipated future development on Daigle Pond watershed approximates 

3.65 kg annually (0.5 x 1 ppb change in trophic state or 7.3 kg). 

 Human population growth will continue to occur in the Daigle Pond watershed, contributing new 

sources of phosphorus to the lake. Hence, existing phosphorus source loads must be reduced by at 

least 3.65 kg to allow for anticipated new sources of phosphorus to Daigle Pond. 

 Overall, the presence of nuisance algae blooms in Daigle Pond may be reduced, along with halting 

the trend of increasing trophic state, if the existing phosphorus loading is reduced by approximately 

252 kg TP/yr. 

Internal Lake Sediment Phosphorus Mass: The relative contribution of internal sources of total 

phosphorus within Daigle Pond - in terms of sediment TP recycling - were analyzed (using lake 

volume-weighted mass differences between early and late summer) and estimated on the basis of 

water column TP data. The only year for which adequate lake profile TP concentration was available 

to derive reliable estimates (26 kg) of internal lake mass was in 1995. 

Linking Pollutant Loading to a Numeric Target: The basin loading assimilative capacity for colored

Daigle Pond was set at 116 kg/yr of total phosphorus to meet the numeric water quality target of 16 

ppb of total phosphorus. A phosphorus retention model, calibrated to in-lake phosphorus data, was 

used to link phosphorus loading to numeric target. 

Supporting Documentation for the Daigle Pond TMDL Analysis includes the following: Maine DEP 

and VLMP water quality monitoring data, and specification of a phosphorus retention model – 

including both empirical models and retention coefficients.
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

29 

Daigle Pond Total Phosphorus Retention Model 

(after Dillon and Rigler 1974 and others) 

 L = P (A z p) / (1-R) where, 1 ppb change = 7.3 kg

 116 = L = external total phosphorus load capacity (kg TP/year) 

 16 = P = total phosphorus concentration (ppb) = Target Goal = 16 ppb

 0.14 = A = lake basin surface area (km2

)=14 ha or 34 acres 

 2.0 = z = mean depth of lake basin (m) A z p = 6.0

 21.3 = p = annual flushing rate (flushes/year) 

 0.82 = 1- R = phosphorus retention coefficient, where: 

 0.18 = R = 1 / (1+ sq. rt. p) (Larsen and Mercier 1976)

 

 Previous use of the Vollenwieder (Dillon and Rigler 1974) type empirical model for Maine lakes, 

e.g., Cobbossee, Madawaska, Sebasticook, East, China, Mousam, Highland (Falmouth), Webber, 

Threemile, Threecornered, Annabessacook, Pleasant, Sabattus, Toothaker, Unity, Upper Narrows, 

Highland (Bridgton), Little Cobbossee, Long (Bridgton), Togus, Duckpuddle, Lovejoy, Lilly and 

Sewall PCAP-TMDL reports (Maine DEP 2000-2006) have all shown this approach to be effective in 

linking watershed total phosphorus (external) loadings to existing in-lake total phosphorus 

concentrations. 

Strengths and Weaknesses in the Overall TMDL Analytical Process: The Daigle Pond TMDL 

was developed using existing lake water quality monitoring data, derived watershed export 

coefficients (Reckhow et al. 1980, Maine DEP 1981 and 1989, Dennis 1986, Dennis et al. 1992, 

Bouchard et al. 1995, Soranno et al. 1996, and Mattson and Isaac 1999) and a phosphorus retention 

model which incorporates both empirically derived and observed retention coefficients (Vollenwieder 

1969, Dillon 1974, Dillon and Rigler 1974 a and b, and 1975, Kirchner and Dillon 1975). Use of the 

Larsen and Mercier (1976) total phosphorus retention term, based on localized data (northeast and 

north-central U.S.) from 20 lakes in the US-EPA National Eutrophication Survey (US-EPA-New 

England) provides a more accurate model for northeastern regional lakes. 

Strengths: 

 Approach is commonly accepted practice in lake management 

 Makes best use of available water quality monitoring data 

 Based upon experience with other lakes in the northeastern U.S. region, the empirical 

phosphorus retention model was determined to be an adequate estimator of future lake 

conditions. However, some uncertainty exists due to the relatively higher annual flushing rate of 

21.3 and the complicated hydrology of Daigle Pond.

Weaknesses: 

 Inherent uncertainty of TP load estimates (Reckhow 1979, Walker 2000) and associated 

variability and generality of TP loading coefficients. 

Critical Conditions occur in Daigle Pond during the summertime, when the potential (both 

occurrence and frequency) of nuisance algae blooms are greatest. The loading capacity of 16 ppb

of total phosphorus was set to achieve desired water quality standards during this critical time 

period, and will also provide adequate protection throughout the year (see Seasonal Variation). 

LOAD ALLOCATIONS (LA’s) - The load allocation for Daigle Pond equals 116 kg TP on an annual 

basis and represents, in part, that portion of the lake’s assimilative capacity allocated to non-point 

(overland) sources of phosphorus (from Table 2). Direct external TP sources (totaling 1,269 kg 

annually) have been identified and accounted for in the land-use breakdown portrayed in Table 2 

(corrected GIS). Further reductions in non-point source phosphorus loadings are expected from the 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

30 

View of the Daigle Pond watershed looking south-east, towards Cross Lake. 

continued implementation of NPS best management practices (see summary, pages 17-20). As 

previously mentioned, it was not possible to separate natural background from non-point pollution 

sources in this watershed because of the limited and general nature of the available information. As in 

other Maine TMDL lakes (see Sebasticook Lake, East Pond, China Lake, and subsequent TMDLs), inlake nutrient loadings in Daigle Pond originate from a combination of direct external and internal (lake 

sediment) sources of total phosphorus. 

WASTE LOAD ALLOCATIONS (WLA's): Since there are no known existing point sources of 

pollution (including regulated storm-water sources) in the Daigle Pond watershed, the waste load 

allocation (WLA) is set at 0 (zero) and all of the loading capacity is allocated as a gross allotment to 

the “load allocation”. 

MARGIN OF SAFETY (MOS): The TMDL expressed in terms of annual and daily loads includes an 

implicit MOS through the relatively conservative selection of the numeric water quality target (based 

on a state-side database for lakes, supported by in-lake data). Based on both the Daigle Pond 

historical records and a summary of statewide Maine lakes water quality data for colored (> 30 SPU) 

lakes - the target of 16 ppb (116 kg/yr in Daigle Pond) represents a highly conservative goal to assure 

future attainment of Maine DEP water quality goals of non-sustained and non-repeated blue-green 

summer-time algae blooms due to NPS pollution or cultural eutrophication and stable or decreasing 

trophic state. The statewide data base for colored Maine lakes indicate that summer nuisance algae 

blooms (growth of algae which causes water transparency to be less than 2 meters) are more likely to 

occur at 18 ppb or above. 

SEASONAL VARIATION: The Daigle Pond TMDL is protective of all seasons, as the allowable 

annual load was developed to be protective of the most sensitive time of year – during the summer, 

when conditions most favor the growth of algae and aquatic macrophytes. Maine DEP lake biologists, 

as a general rule, use more than six flushes annually (bi-monthly) as the cutoff for considering 

seasonal variation as a major factor (to distinguish lakes vs. rivers) in the evaluation of total 

phosphorus loadings in aquatic environments in Maine. With an average flushing rate of 21.3 flushes/

year, average monthly phosphorus loads are most critical to the water quality in Daigle Pond. 

Nonpoint source best management practices (BMPs) proposed for the Daigle Pond watershed have 

been generally designed to address total phosphorus loading during all seasons. 

 This variation is further accounted for in calculations of seasonal (May-October, November– April), 

monthly, and daily TP load calculations (see page 31). These numbers are derived from formulas 

developed by Dudley (2004) for ungauged rivers in Maine, and are based on several physical and 

geographic parameters including: 1) drainage area of the waterbody, 2) percent of sand and gravel 

aquifers in the drainage area, 3) distance from a stationary line along the Maine coast, and 4) mean 

annual precipitation. Daily loading rates are then determined using variables from Dillon and Rigler 

(1974) for calculating the external total phosphorus load capacity (page 27) for the lake. 

 

 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

31 

Vollenweider: L = P (Azp) / (1-R)

L = external P load capacity (kg TP/yr) 116 P = total P concentration (ppb) 16 A = lake basin surface area (km2) 0.14 z = mean depth of lake basin (m) 2 p = annual flushing rate 21.3 1-R = P retention coefficient 0.82 R = 1 / (1 + sq. rt. p) 0.18 

Season % of Total # Flushes 

May-October 44% 9.3 November - April 56% 12.0 

Daigle Pond Daily Load vs. Daily Discharge

1.000.800.600.400.200.00

Jan

Feb

March

April

May

June

July

August

September

October

November

December

kg TP/day

10.008.006.004.002.000.00

ft^3/s

Discharge per DayDaily Load

Month Discharge/ Month (ft^3/s) % of Total Flushes/ Month Monthly Load Capacity (kg) Discharge/ Day (ft^3/s) Flushes/Day Daily Load Capacity (kg) 

Jan 1.45 3% 0.66 3.6 0.05 0.02 0.12 

Feb 1.36 3% 0.62 3.4 0.05 0.02 0.12 

March 3.35 7% 1.53 8.3 0.11 0.05 0.27 

April 10.41 24% 5.19 28.3 0.35 0.17 0.94 

May 11.22 24% 5.11 27.9 0.36 0.16 0.90 

June 3.33 7% 1.52 8.3 0.11 0.05 0.28 

July 1.25 3% 0.57 3.1 0.04 0.02 0.10 

August 0.92 2% 0.42 2.3 0.03 0.01 0.07 

September 1.11 2% 0.51 2.8 0.04 0.02 0.09 

October 2.59 6% 1.18 6.4 0.08 0.04 0.21 

November 5.65 12% 2.57 14.0 0.19 0.09 0.47 December 3.15 7% 1.44 7.8 0.10 0.05 0.25 

Daigle Pond Daily Load Calculations
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

32 

PUBLIC PARTICIPATION: Adequate (‘full and meaningful’) public participation in the Daigle Pond

PCAP-TMDL development process was ensured - during which land use and phosphorus load 

reductions were discussed - through the following avenues: 

1. September 26, 2005: MACD staff traveled to Aroostook County to meet with staff from Maine 

DEP and the SJV-SWCD to gather information and discuss the water quality of Daigle Pond. 

2. September 27, 2005: MACD staff met with Maine DEP and SJV-SWCD staff in the field and 

were given a tour of the Daigle Pond watershed.. 

3. February 1, 2006: MACD staff Tricia Rouleau contacted the SJV-SWCD to discuss BMPs that 

have been installed in the watershed. 

4. February 7, 2006: MACD staff Jennifer Jespersen contacted Kathy Hoppe and Heidi Royal , 

SA-SWCD and SJV-SWCD staff, to gather historical information about the Daigle Pond 

watershed. 

5. February 8, 2006: MACD staff Tricia Rouleau contacted Heidi Royal at the SJV-SWCD about 

the Daigle Pond watershed survey. 

6. February 9, 2006: MACD staff Tricia Rouleau created and sent GIS land use maps to Heidi 

Royal at the SJV-SWCD for review. 

7. May 2, 2006: MACD sent a pre-draft report to the SJV-SWCD Board and staff for review. 

8. June 29, 2006: MACD and SJV-SWCD sponsored a public meeting at the New Canada 

Community Center to discuss the Daigle Pond TMDL and to receive stakeholder feedback. 

9. June 30, 2006: MACD staff reviewed land use maps of the Daigle Pond watershed at the SJVSWCD office in Ft. Kent. 

STAKEHOLDER AND PUBLIC REVIEW PROCESS 

 

 A two-week stakeholder review was distributed electronically on July 5, 2006 to the following 

individuals who expressed a specific interest, participated in the field work or helped develop the 

draft Daigle Pond PCAP-TMDL report: Maine DEP (Kathy Hoppe and Bill Sheehan); St. John 

Valley SWCD staff (Heidi Royal); Maine Department of Inland Fisheries and Wildlife (Dave Basley); 

Maine Forest Service (Chris Martin) and Maine Department of Agriculture (David Rocque). 

 The following statement was advertised in the Bangor Daily News over a month long (2-

weekend) period (August 12-13 and August 19-20, 2006), and in the St. John Valley Times over a 

four-week period beginning the week of August 7, 2006: 

DAIGLE POND - New Canada and Fort Kent

 In accordance with Section 303(d) of the Clean Water Act, and implementation regulations in 40 

CFR Part 130 - the Maine Department of Environmental Protection has prepared a combined 

Phosphorus Control Action Plan (PCAP) and Total Maximum Daily Load (TMDL) nutrient report 

(DEPLW 0789) for the DAIGLE POND WATERSHED, located within the Towns of New Canada and 

Fort Kent. This PCAP-TMDL report identifies and provides best estimates of non-point source 

phosphorus loads for all representative land use classes in the DAIGLE POND direct watershed and 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

33 

the total phosphorus reductions required to restore and maintain acceptable water quality conditions. 

A Public Review draft of this report may be viewed at Maine DEP Northern Maine Regional offices in 

Presque Isle (1235 Central Drive, Skyway Park) or at the Central Maine DEP offices in Augusta (Ray 

Building, Hospital Street - Route 9, Land & Water Bureau) or on-line: http://www.maine.gov/dep/blwq/

comment.htm. Please send all comments, in writing by September 1, 2006 to Dave Halliwell, Lakes 

TMDL Program Manager, Maine DEP, State House Station #17, Augusta, ME 04333. or e-mail: 

david.halliwell@maine.gov

PUBLIC REVIEW Comments Received

 No further comments were received during this 30-day public review period for Daigle Pond.

 

 Subsequently, an internal review by Maine-DEP requested the inclusion of 303(d) listed Daigle 

Brook - outlet stream from Daigle Pond, into the lake PCAP-TMDL report. The following Addendum

was added to the report and released for Public Review during the 10-day period (August 28th to 

September 8th, 2006), as advertised in the Bangor Daily News and posted on the Maine DEP 

website. 

DAIGLE Brook, Aroostook County - Total Maximum Daily Load (TMDL) Report Addendum

(change notification)

 The development of the Daigle Pond TMDL (DEPLW 2006-0789) and selection of a numeric water 

quality target of 16 ppb total phosphorus is protective of downstream uses in Daigle Brook, which is 

also water quality impaired and 303(d) listed. The water quality impairment of Daigle Brook is due to 

dissolved oxygen loss related to primary productivity caused by excessive pollutants (total 

phosphorus) from Daigle Pond and the brook's direct watershed within the Cross Lake drainage 

system. The planned reduction of total phosphorus loading to Daigle Brook (a primary nutrient source 

for downstream Cross Lake) coupled with the attainment of the in-lake target of 16 ppb in Daigle Pond 

will provide for attainment and maintenance of water quality standards in the brook. Following final 

EPA approval of the Daigle Pond and Cross Lake TMDL (DEPLW 2006-0790), Daigle Brook will be 

re-designated from the 303(d) list to category 4A (TMDL approved). Please send any public 

comments, in writing by September 8, 2006 to Dave Halliwell, Lakes TMDL Program Manager, Maine 

DEP, State House Station #17, Augusta , ME 04333, or e-mail: David Halliwell. 

 No further comments were received during this 10-day public review period for Daigle Brook

 Final changes to the draft Public Review report, as a result of this addendum, include naming 

Daigle Brook as a 303 (d) listed water body in the 'Drainage System' section of this report (page 9), 

and addition of language from the Daigle Brook addendum into the 'Numeric Water Quality Target' 

section (page 24). 

 Further agency review (US-EPA) comments requested additional justification of the link between 

the annual load and the annual flushing rate of Daigle Pond. Changes were made to the 'Annual/Daily 

Load Capacity' section (page 27), as well as the 'Seasonal Variation' section (page 30), to further 

discuss and account for the relatively high annual flushing rate. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

34 

LITERATURE 

Lake Specific References

Bouchard, R. 1995. Maine Department of Environmental Protection Memorandum. Restoration 

 Proposal: Daigle Pond. March 10, 1995. 

Bouchard, R. 1996. Project Review Notes: Daigle Pond Proposal of October 1994. March 1, 1996. 

DPRC. nd. Daigle Pond Restoration Committee. Daigle Pond Water Quality Demonstration Project. 

Fort Kent, Maine. 

Ferwerda, J., LaFlamme, K., Kalloch, N., and Rourke, R. 1997. The Soils of Maine. Maine Agricultural 

and Forest Experiment Station, University of Maine, Orono, Maine. 

Maine VLMP. 2005. Maine Volunteer Lake Monitoring Program. Water Quality Summary: Daigle Pond, 

New Canada, Aroostook County, Midas 1665. Maine DEP, Augusta Maine. 

NRCS. Natural Resources Conservation Service. n.d. Aroostook County/St. John Valley Success 

Stories (Fort Kent Field Office): Nutrient and Sediment Control System Completed. Retrieved 

March 21, 2006 from http://www.me.nrcs.usda.gov/features. 

SJV-SWCD. 1996. St. John Valley Soil and Water Conservation District. Daigle Pond Watershed 

Restoration Project Survey. Fort Kent, Maine. 

SJV-SWCD. 2003. St. John Valley Soil and Water Conservation District. Daigle Pond 319 All Wrapped 

Up. Nonpoint Source Times. 12(1): 5-6. 

State of Maine. 1999. Maine Nonpoint Source Control Program: Program Upgrade and 15 Year 

Strategy. Augusta, Maine. September 23, 1999. 

General References

Barko, J.W., W.F. James, and W.D. Taylor. 1990. Effects of alum treatment on phosphorus and 

phytoplankton dynamics in a north-temperate reservoir: a synopsis. Lake and Reservoir 

Management 6:1-8. 

Basile, A.A. and M.J. Vorhees. 1999. A practical approach for lake phosphorus Total Maximum Daily 

Load (TMDL) development. US-EPA Region I, Office of Ecosystem Protection, Boston, MA (July 

1999). 

Bostrom, B., G. Persson, and B. Broberg. 1988. Bioavailability of different phosphorus forms in 

freshwater systems. Hydrobiologia 170:133-155. 

Bouchard, R., M. Higgins, and C. Rock. 1995. Using constructed wetland-pond systems to treat 

agricultural runoff: a watershed perspective. Lake and Reservoir Management 11(1):29-36. 

Butkus, S.R., E.B. Welch, R.R. Horner, and D.E. Spyridakis. 1988. Lake response modeling using 

biologically available phosphorus. Journal of the Water Pollution Control Federation 60:1663-69. 

Carlton, R.G. and R.G. Wetzel. 1988. Phosphorus flux from lake sediments: effect of epipelic algal 

oxygen production. Limnology and Oceanography 33(4):562-570. 

Chapra, S.C. 1997. Surface Water-Quality Modeling. McGraw-Hill Companies, Inc. 
Final EPA Review Document Daigle Pond PCAP-TMDL Report 

35 

Correll, D.L., T.L. Wu, E.S. Friebele, and J. Miklas. 1978. Nutrient discharge from Rhode Island 

watersheds and their relationships to land use patterns. In: Watershed Research in Eastern North 

America: A workshop to compare results. Volume 1, February 28 - March 3, 1977. (mixed pine/

hardwoods) 

Dennis, W.K. and K.J. Sage. 1981. Phosphorus loading from agricultural runoff in Jock Stream, 

tributary to Cobbossee Lake, Maine: 1977-1980. Cobbossee Watershed District, Winthrop. 

Dennis, J. 1986. Phosphorus export from a low-density residential watershed and an adjacent 

forested watershed. Lake and Reservoir Management 2:401-407. 

Dennis, J., J. Noel, D. Miller, C. Elliot, M.E. Dennis, and C. Kuhns. 1992. Phosphorus Control in Lake 

Watersheds: A Technical Guide to Evaluating New Development. Maine Department of 

Environmental Protection, Augusta, Maine. 

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Water Resources Bulletin 10:969-989. 

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Draft Prepared for NEIWPCC and EPA Region. 

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