vvEPA
United States
Environmental Protection
Agency
Region V
Great Lakes National
Program Office
230 South Dearborn
Chicago, IL 60604
EPA-905/9-78-002
C.I
The Felton-Herron Creek,
Mill Creek
Pilot Watershed Study
1) Lansing
2) Grand Rapids
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The U.S. Environmental Protection Agency was created because
of increasing public and governmental concern about the dangers
of pollution to the health and welfare of the American people.
Noxious air, foul water, and spoiled land are tragic testimony
to the deterioration of our natural environment.
The Great Lakes National Program Office (GLNPO) of the U.S. EPA,
was established in Region V, Chicago to provide a specific focus
on the water quality concerns of the Great Lakes. GLNPO provides
funding and personnel support to the International Joint Commission
activities under the US-Canada Great Lakes Water Quality Agreement.
Several land use water quality studies have been funded to support
the Pollution from Land Use Activities Reference Group (PLUARG)
under the Agreement to address specific objectives related to
land use pollution to the Great Lakes. This report describes
some of the work supported by this Office to carry out PLUARG study
objectives.
We hope that the information and data contained herein will help
planners and managers of pollution control agencies make better
decisions for carrying forward their pollution control responsi-
bilities.
Dr. Edith J. Tebo
Director
Great Lakes National Program Office
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EPA-905/9-78-002
THE FELTON-HERRON CREEK, MILL CREEK PILOT WATERSHED STUDIES
by
Thomas M. Burton
Institute of Water Research
Michigan State University
East Lansing, Michigan 48824
Grant Number R005143-01
Project Officer
Carl Wilson
U.S. Environmental Protection Agency
Region V
230 South Dearborn Street
Chicago, Illinois 60604
This study was conducted as part of the
Task C - Pilot Watershed Program
for the International Reference Group on
Pollution from Land Use Activities
Great Lakes Regional Office
International Joint Commission
Windsor, Ontario, Canada N9A 6T3
GREAT LAKES NATIONAL PROGRAM OFFICE
U.S. ENVIRONMENTAL PROTECTION AGENCY
230 SOUTH DEARBORN STREET
CHICAGO, ILLINOIS 60604
C-
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DISCLAIMER
This report has been reviewed by the Region V Office, U.S. Environ-
mental Protection Agency, and approved for publication. Approval does not
signify that the contents necessarily reflect the views and policies of the
U.S. Environmental Protection Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
The findings and views expressed in this report are those of the
project investigators and do not necessarily reflect the views of the
International Joint Commission or the International Reference Group on
Great Lakes Pollution from Land Use Activities.
ii
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ABSTRACT
Two land uses, (1) fruit orchard farming and (2) land application of
municipal wastewater irrigation were studied to assess the sources, forms,
and amount of pollutants that are transported from these areas to the
boundary waters of the Great Lakes. The primary concern of the Mill Creek
study was the movement of pesticides from fruit orchards while the primary
concern of the wastewater irrigation study (Felton-Herron Creek study) was
the transport of nutrients.
Analyses were conducted for 57 different pesticides on both suspended
sediment and dissolved in water in the Mill Creek study. Of the eight
pesticides found in appreciable quantities, the major forms exported-5 were
the chlorinated hydrocarbons, although they have not been used for several
years. Most of the pesticides were transported on suspended solids. The
pesticides lost in order of amount lost were DDT, DDE, Atrazine, Dieldrin,
DDD, Simazine, Aldrin, and Guthion. Most pesticides lost were associated
with past farming practices (e.g., DDT, DDE, DDD) or corn cultivation in
the watershed (e.g., Atrazine) with Guthion being the only major pesticide
associated with fruit orchard farming lost from the watershed. It was lost
in only very small amounts. Losses of suspended sediment from this water-
shed were low compared to most midwestern watersheds while nutrient losses
were comparable to losses from other agricultural watersheds in the Great
Lakes Basin.
The Felton-Herron Creek study demonstrated that improper management
of land application systems for recycling municipal wastewater can lead
to appreciable loading of streams with all the major nutrients, especially
nitrogen. Proper management of such systems will control these losses.
Perennial crops and oldfield systems are very efficient at uptake of both
N and P throughout the growing season and offer excellent wastewater reno-
vation potential. Annual crops such as corn are not efficient at nitrogen
uptake during the early growth phase (first five to seven weeks). After
that, they are also very efficient at nitrogen uptake. Late successional
forests are not efficient at nitrogen uptake and losses to groundwater or
runoff often approach input amounts. A variety of harvest managements and
winter spray feasibility were also investigated in this study. The effect
of these managements on nutrient losses are also discussed in detail.
iii
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CONTENTS
Abstract ^
Figures vii
Tables x
Acknowledgment xvi
1. Introduction 1
Felton-Herron Creek 1
Mill Creek 2
2. Conclusions 4
Felton-Herron Creek ... 4
Mill Creek 7
3. Recommendations: Implications for Remedial Measures .... 8
Felton-Herron Creek 8
Mill Creek 11
4. Introduction to Felton-Herron Creek Watershed Studies ... 13
Description of Study Area 14
General Study Approach 20
References 24
5. Land Application of Municipal Effluent on Oldfields
and on Grass Lands 25
Introduction 25
Materials and Methods 26
Results and Discussion 29
Conclusions and Recommendations 59
References 63
6. Land Application to Croplands 66
Introduction 66
Materials and Methods 67
Results and Discussion 70
Conclusions and Recommendations 83
References 85
iv
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7. Application of Municipal Wastewater to Forest Lands .... 86
Introduction 86
Materials and Methods 87
Results and Discussion 88
Conclusions/Remedial Measures 116
References 117
8. Winter Spray Irrigation of Secondary Municipal
Effluent in Michigan 121
Introduction 121
Description of the Study Area 122
General Methods 123
Computational Methods 125
Overall Results for Study Period 128
Winter 1977 Results 131
Conclusions and Application 134
References 139
9. Baseline Oldfield Watershed Studies 140
Introduction 140
Materials and Methods 141
Results and Discussion 142
Conclusions 152
References 153
10. Introduction to Mill Creek Studies 154
Description of the Study Area 155
11. Nutrient Exports from the Mill Creek Watershed 158
Introduction 158
Materials and Methods 158
Results and Discussion 159
Conclusions 162
References 166
12. Mill Creek Suspended Sediment Studies 167
Introduction 167
Materials and Methods 168
Results and Discussion 169
Conclusions 174
References 177
v
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13. Mill Creek Pesticide Studies 180
Introduction 180
Methods 183
Results 186
Discussion 189
Summary 213
vi
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FIGURES
Number Page
4-1 Looking northwest at Lakes 1, 2, 3, and 4 15
4-2 Photograph of the Spray Irrigation Area showing
major research areas 16
4-3 Soil map of the spray irrigation site 18
4-4 Location and station designation of existing water
quality monitoring points. Sampling stations enclosed
by a rectangle denote location of recording stream
gauging stations 21
5-1 Weekly average mineral N concentrations in applied
effluent and in soil-water from the 15 cm depth of
the 7.5 cm/week irrigation rate on bluegrass managed
with various cutting treatments 31
5-2 Weekly average mineral N concentrations in applied
effluent and in soil-water from the 150 cm depth of
the 7.5 cm/week irrigation rate on bluegrass managed
with various cutting treatments 32
5-3 Weekly average mineral N concentrations in applied
effluent and in soil-water from the 15 cm depth of
the 5 cm/week irrigation rate on the oldfield waste-
water irrigation site for various cutting treatments .... 40
5-4 Weekly average mineral N concentrations in applied
effluent and in soil-water from the 15 depth of the
10 cm/week irrigation rate on the oldfield waste-
water irrigation site for various cutting treatments .... 41
5-5 Weekly average mineral N concentrations in applied
effluent and in soil-water from the 120 cm depth of the
5 cm/week irrigation rate on the oldfield wastewater
irrigation site for various cutting treatments 42
5-6 Weekly average mineral N concentrations in applied effluent
and in soil-water from the 120 cm depth of the 10 cm/week
irrigation rate on the oldfield wastewater irrigation site
for various cutting treatments 43
vii
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Figure Page
5-7 Concentration versus discharge for total P, total N,
and N03-N for a wastewater irrigation generated runoff
event (August 16, 1976) 60
5-8 Concentration versus discharge for total P, total N,
and NC-3-N for a wastewater irrigation generated runoff
event (July 12, 1976) 61
6-1 Weekly average mineral N concentrations in applied effluent
and in soil-water from the 15 cm depth of the 2.5 cm/week
irrigation rate of the various crop types 72
6-2 Weekly average mineral N concentrations in applied effluent
and in soil-water from the 15 cm depth of the 5.0 cm/week
irrigation rate of the various crop types 73
6-3 Weekly average mineral N concentrations in applied effluent
and in soil-water from the 15 cm depth of the 7.5 cm/week
irrigation rate of the various crop types 74
6-4 Weekly average mineral N concentrations in applied effluent
and in soil-water from the 150 cm depth of the 2.5 cm/week
irrigation rate of the various crop types 75
6-5 Weekly average mineral N concentrations in applied effluent
and in soil-water from the 150 cm depth of the 5.0 cm/week
irrigation rate of the various crop types 76
6-6 Weekly average mineral N concentrations in applied effluent
and in soil-water from the 150 cm depth of the 7.5 cm/week
irrigation rate of the various crop types 77
7-1 Inorganic N concentrations in soil-water at the 150 cm
depth for the non-irrigated forest area 89
7-2 Chloride concentrations as a function of depth and time
for the Forest Irrigation Site 92
7-3 Inorganic N concentrations in soil-water at the 150 cm
depth for the 5 cm/week forest wastewater application
area 94
7-4 Inorganic N concentrations in soil-water at the 150 cm
depth for the 10 cm/week forest wastewater application
area 96
7-5 Concentrations of nitrate and total inorganic N in
wastewater input and nitrate-N in soil-water samples
for the forested sites 97
viii
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Figure FaSe
8-1 Detail map of winter spray site 124
8-2 Runoff monitoring station 126
8-3 Monthly nitrogen to chloride ratios 132
8-4 Winter 1977 lysimeter data 135
8-5 Average daily runoff water quality and discharge,
Winter 1977 136
8-6 Hydrograph and nutrient mass flows, March 9, 1977 137
10-1 Mill Creek watershed 156
12-1 The suspended sediment versus stream discharge
relationship for Mill Creek at station 5. This
station drains the 3058 ha Mill Creek watershed 170
12-2 The stream discharge-stream velocity relationship
for Mill Creek at station 5 171
12-3 Mean monthly stream discharge and suspended sediment
losses from the 3058 ha Mill Creek watershed
(station 5, Figure 10-1) 173
12-4 Particle size distribution of particles less than 100
microns in size transported during low flow periods on
October 28, 1976 and on November 28, 1976 175
13-1 Map of the nine permanent sampling stations established
on Mill Creek 181
13-2 Graphic printout example of application rates and seasonal
distribution of application for Guthion in the Mill Creek
watershed (1976). Values in Ibs/acre 188
13-3 Variation of pesticide concentration and flow rate
over a hydrologic event 190
13-4 Variation of pesticide concentration and flow rate
over a hydrologic event 191
13-5 Variation of pesticide concentration and flow rate over
a hydrologic event 192
13-6 Schematic outline of major processes which affect
adsorption and transport of nonsoluble pollutants
in water 207
ix
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TABLES
Table page
4-1 Summary of Water Flows for the Water Quality
Management Facility, January 1 to October 28, 1977 17
4-2 Summary of Wastewater Irrigation on the Land Site
for 1977 (January 1 to October 28) 17
4-3 General Soil Description of the Spray Irrigation Site ... 19
5-1 Mean Annual Concentration and Total Amounts of
Wastewater Constituents Applied to the Grass Management
Site from 7.5 cm/week of Wastewater Irrigation 30
5-2 Mean Annual Concentration and Total Amounts of Wastewater
Constituents Applied to the Irrigated Areas of the Old-
field Site 33
5-3 Mean Annual Yield, N and P Content and N and P Removals
of the Harvested Plots of the Oldfield Site 35
5-4 Mass Balance for Inorganic N for the 0 cm/week Oldfield
Site 36
5-5 Mass Balance for Inorganic N for the 5 cm/week Oldfield
Site 37
5-6 Mass Balance for Inorganic N for the 10 cm/week Oldfield
Site 38
5-7 Mean Annual Organic Plus Ammonia Nitrogen Concentration
in Soil-Water Samples taken from the Topsoil and from
Below the Root Zone of the Oldfield Wastewater Irrigation
Site, 1976 44
5-8 Mean Annual Orthophosphate Concentration in Soil-Water
Samples taken from the Topsoil and from Below the Root
Zone of the Oldfield Irrigation Site, 1976 44
5-9 Phosphorus Mass Balance for 1976 for the Various
Treatments of the Oldfield Site 45
5-10 Bray Extractable Phosphorus Analyses of Soils for the
Oldfield Wastewater Irrigation Study 46
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Table
5-10 Bray Extractable Phosphorus Analyses of Soils
for the Oldfield Wastewater Irrigation Study
46
5-11 Exchangeable Potassium Analyses of Soils for
the Oldfield Wastewater Irrigation Study .......... 47
5-12 Exchangeable Calcium Analyses of Soils for the
Oldfield Wastewater Irrigation Study ............ 48
5-13 Exchangeable Magnesium Analyses of Soils for
the Oldfield Wastewater Irrigation Study .......... 49
5-14 Exchangeable Sodium Analyses of Soils for
the Oldfield Wastewater Irrigation Study .......... 50
5-15 Potassium Sulfate Extractable Chloride Analyses
of Soils for the Oldfield Wastewater Irrigation Study ... 51
5-16 Potassium Sulfate Extractable Nitrate-Nitrogen
Analyses of Soils for the Oldfield Wastewater
Irrigation Study ...................... 52
5-17 Stream Export of Molybdate Reactive Phosphorus and
Total Phosphorus from the 11.32 ha Oldfield Irrigation
Site ............................ 54
5-18 Stream Export of Nitrate and Ammonia Nitrogen from the
11.32 ha Oldfield Irrigation Site ............. 55
5-19 Stream Export of Nitrite and Kjeldahl Nitrogen from the
11.32 ha Oldfield Irrigation Site ............. 56
5-20 Stream Export of Chloride and Suspended Solids from
the 11.32 ha Oldfield Irrigation Site ........... 57
5-21 Stream Export of Sodium and Calcium from the 11.32 ha
Oldfield Irrigation Site .................. 58
6-1 Mean Concentrations of Bray Extractable P, Exchangeable
Cations and pH of all Treatment Plots at the Start of the
1976 to 1977 Study Period ................. 67
6-2 Monthly and Yearly Applications of Crop Nutrients
and Salts on the 7.5 cm/week Irrigation Rate ........ 70
78
6-3 Mass Balance for Inorganic N for the 2.5 cm/week
Crop Site (•
6-4 Mass Balance for Inorganic N for the 5.0 cm/week
Crop Site 79
xi
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Table
Page
6-5 Mass Balance for Inorganic N for the 7.5 cm/week
Crop Site 79
6-6 Mean Annual Organic Plus Ammonium Nitrogen Concentration
in the Soil-Water Samples taken from the Topsoil and
from Below the Root Zone of the Cropland Irrigation
Area, 1976 81
6-7 Mean Annual Orthophosphate Concentration in the Soil-
Water Samples taken from the Topsoil and from Below
the Root Zone, 1976 81
6-8 Mean Annual Concentration of Cations in the Effluent
and in the Soil-Water Samples taken from the Topsoil
and from Below the Root Zone of the Cropland Irrigation
Areas, 1976 82
7-1 Water Budget for Non-Irrigated Forest 90
7-2 Mass Balance for Inorganic Nitrogen (NC>3 + N02 + NIty-N)
for the 5 cm/week Forest Irrigation Site 93
7-3 Mass Balance for Inorganic Nitrogen (NC^ + N02 + NH^-N)
for the 10 cm/week Forest Irrigation Site 93
7-4 Monthly Average Wastewater Input Concentrations for
the 5 cm/week Spray Site 98
7-5 Mass Balance for Organic Nitrogen for the 5 cm/week
Forest Irrigation Site 99
7-6 Mass Balance for Organic Nitrogen for the 10 cm/week
Forest Irrigation Site 99
7-7 Water Budget for the 10 cm/week Forest Irrigation Site . . . 100
7-8 Water Budget for the 5 cm/week Forest Irrigation Site . . . 102
7-9 Mass Balance Budget for Total Phosphorus for the
5 cm/week Forest Irrigation Site 102
7-10 Mass Balance for Total Phosphorus for the 10 cm/week
Forest Irrigation Site 103
7-11 Monthly Wastewater Input and Output (150 cm depth)
Total P Concentrations for the Forested Sites 104
7-12 Nitrate-Nitrogen Analyses of Soils from the Forest
Wastewater Irrigation Study 105
xii
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Table PaSe
7-13 Bray Extractable Phosphorus and Ammonium-Nitrogen
Analyses of Soils from the Forest Wastewater
Irrigation Study . 106
7-14 Sodium and Potassium Analyses of Soils from the
Forest Wastewater Irrigation Study 107
7-15 Calcium and Magnesium Analyses of Soils from the
Forest Wastewater Irrigation Study 108
7-16 Chloride Analyses of Soils from the Forest Wastewater
Irrigation Study 109
7-17 Stream Export of Molybdate Reactive Phosphorus
and Total Phosphorus from the 18.35 ha Forested Area .... Ill
7-18 Stream Export of Nitrate and Ammonia Nitrogen
from the 18.35 ha Forested Area 112
7-19 Stream Export of Nitrite and Kjeldahl Nitrogen
from the 18.35 ha Forested Area 113
7-20 Stream Export of Chloride and Suspended Solids
from the 18.35 ha Forested Area 114
7-21 Stream Export of Sodium and Calcium from the
19.35 ha Forested Area 115
8-1 Overall Water Balance for Study Period
December 1, 1975 to March 16, 1977 129
8-2 Runoff, Infiltration, and Evapotranspiration as
Percent of Total Water Input by Season 129
8-3 Overall Nutrient Mass Balances for Study Period
December 1, 1975 to March 16, 1977 130
8-4 Nutrient Reduction in the Soil by Season 130
8-5 Water Balances - Winter 1977, December 1, 1976
to March 16, 1977 133
8-6 Nutrient Balance - Winter 1977, December 1, 1976
to March 16, 1977 133
9-1 Water Budgets for the Oldfield Baseline Watershed 143
9-2 Stream Export of Molybdate Reactive Phosphorus and
Total Phosphorus from the 7.73 ha Baseline Oldfield
Watershed 145
xiii
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Table
9-3 Stream Export of Nitrate and Ammonia Nitrogen
from the 7.73 ha Baseline Oldfield Watershed 146
9-4 Stream Export of Nitrite and Total Kjeldahl Nitrogen
from the 7.73 ha Baseline Oldfield Watershed 147
9-5 Stream Export of Chloride and Suspended Solids
from the 7.73 ha Baseline Oldfield Watershed 148
9-6 Stream Export of Sodium and Calcium
from the 7.73 ha Baseline Oldfield Watershed 149
9-7 Phosphorus, Nitrogen, and Chloride Analyses of
Soils from the Baseline Watershed 151
9-8 Major Exchangeable Cation Analyses for 1976
for the Baseline Watershed Soils 151
10-1 Major Soils of the 3058 ha Mill Creek Watershed 157
11-1 Nutrient Exports from the 3058 ha Mill Creek Watershed ... 160
11-2 Comparison of Annual Estimates for the 3058 ha Mill
Creek Watershed Calculated with Event Versus Non-Event
Strata and Calculated Without Stratification 161
11-3 Nutrient Exports from the 1146 ha Mill Creek Watershed
Above the Confluence with North Branch 163
11-4 Nutrient Exports from the 889 ha North Branch
Subwatershed of Mill Creek 164
11-5 Comparison of Annual Estimates Computed Using Mean
Daily Loadings Versus Estimates Computed with no Strati-
fication for the North Branch Watershed and for the Mill
Creek Watershed above the Confluence with North Branch . . . 165
12-1 Discharge Versus Sediment Export for the 3058 ha
Mill Creek Watershed for the 1975-76 Water Year 172
13-1 Tabular Printout of Pesticide Use in One Farm in
the Mill Creek Basin 187
13-2 Pesticides Analyzed for in the Mill Creek Watershed 193
13-3 Pesticide Exports from the 3058 ha Mill Creek
Watershed, 1975-76 Water Year 194
13-4 Pesticide Exports from the 3058 ha Mill Creek
Watershed, 1976-77 Water Year 195
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Table
13-5 Flow Weighted Mean Concentrations of Pesticides
Exported from the 3058 ha Mill Creek Watershed 196
13-6 Stream Export of Pesticides from the 1146 ha Mill Creek
Watershed Above the Confluence with North Branch 197
13-7 Stream Export of Pesticides from the 889 ha North
Branch Subwatershed of Mill Creek 198
xv
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ACKNOWLEDGMENTS
The author of this study is indebted to the following individuals for
their vital role in completing this study: Charles Annett, William Baker
Thomas Bahr, Robert Ball, Paul Bent, Frank D'ltri, Joe Ervin, Scott Farley,
P. David Fisher, Lester Geissel, Don Herrington, Bobby Holder, James Hook
Darrell King, David Leland, Walter Mack, David Mclntosh, Dan O'Neill,
John Przybyla, Robert Snow, Milo Tesar, Ted Vinson, and Matthew Zabik.
Individual investigators are given credit for their individual studies in
the body of this report. Special thanks are due Paul Bent for his dedicated
efforts to obtain hydrologic measurements for both the Felton-Herron and
Mill Creek Studies, to Rose McCowen for typing this report and for drafting
most of the figures, and to John Przybyla for the computer analysis of
runoff.
The studies reported herein were supported by funds provided through
the U.S. Environmental Protection Agency, Grant Number R005143-01, Thomas
G. Bahr, Principal Investigator. After initiation of the above grant,
certain studies on the Felton-Herron Creek portion of the project were
supplemented through support of two additional grants by the Office of
Water Research and Technology, U.S. Department of the Interior: Grant
Number A-039-MICH and B-091-MICH, Dr. Thomas Burton and Dr. Milo Tesar,
Principal Investigators, respectively.
xvi
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SECTION 1
INTRODUCTION
The Felton-Herron/Mill Creek Study was initiated in 1974 as one of the
Task C Pilot Watershed Studies of the studies requested by the Great Lakes
Pollution from Land Use Activities Reference Group (PLUARG) appointed by
the U.S.-Canada International Joint Commission for Great Lakes Research.
Two Michigan subwatersheds were included as representative U.S. water-
sheds for land drainage studies on the input of polluting materials to the
Great Lakes. One, Felton-Herron Creek, is a subwatershed of the Grand
River with features well suited for investigating land drainage from a muni-
cipal wastewater, land treatment area. The other, Mill Creek, is also a
tributary of the Grand River and represents a basin typical of the large
fruit growing area of southwestern lower Michigan.
STUDY OBJECTIVES
The general purpose of the pilot watershed studies conducted in the
State of Michigan was to evaluate land drainage from agricultural or other
land uses not adequately represented in the other U.S. Watershed Studies.
The two selected for inclusion significantly extend the resolution of the
impact of unique land uses to streams tributary to the Great Lakes.
Felton-Herron Creek
Recent laws have mandated consideration of land application systems
as an alternative to more conventional waste treatment facilities. Such
systems have proliferated in recent years so that several thousand hectares
in the U.S. are presently being irrigated with municipal and industrial
effluent. Such systems often discharge to streams via tiles, surface run-
off, or subsurface seepage and represent potentially significant non-point
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pollution sources both as a consequence of high concentration of nutrients
in the irrigated water and as a result of excessive leaching of native,
residual nutrients from organic matter in the soil or from built-up ferti-
lizer residues. Thus, quantification of runoff and subsurface seepage from
such sites is needed as a first step in development of management techniques
to control such surface and groundwater contamination. Furthermore, land
application systems when replacing conventional wastewater treatment sys-
tems represent a shunt from a point source to a non-point source of poten-
tial pollutants. This concept must be considered when pollutant loading
extrapolations are estimated for future years.
Mill Creek
The objective of this research effort was to assess the magnitude of
the pesticides and sediment transported from a watershed typical of the
kind of agriculture subject to the most intensive pesticide usage in the
Great Lakes Basin; fruit orchard farming.
The pesticide transport process can be divided into two categories:
(1) pesticide transported in solution, and (2) pesticide adsorbed to parti-
culate matter and convected along with the sediment load of the stream.
This distinction is necessary if one is to accurately identify the source
of the problem.
The removal and subsequent transport of agricultural non-point source
pollutants are directly related to the rainfall-runoff. Overland flow is
responsible for the initial movement of pollutants from the land surface
to the stream. Once in the stream, the pollutant may be transported
considerable distances by the stream flow. In the particular case of pes-
ticides the quantity transported is related to the solubility and adsorp-
tive characteristics of the pesticide considered. The translocation of
pesticides that are adsorbed to or coated on sediment particles depends
on the many variables influencing the capability of a stream to transport
sediment, whereas those that are water soluble will be convected in amounts
that are directly proportional to their concentration level and the stream
discharge.
In view of the above description of the processes responsible for the
transport of pesticides, the major ojective of our research effort was to
2
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determine the relative amount of pesticide transported on the suspended
solids and in solution. As a result of such a determination it was then
possible to ascertain the magnitude and source of this non-point source
problem.
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SECTION 2
CONCLUSIONS
FELTON-HERRON CREEK
Application of wastewaters to land offers a waste treatment alterna-
tive to the conventional "concrete and steel" wastewater treatment plant,
especially for small to medium sized communities. This technology has
already been adopted by several communities in the Great Lakes Basin, and
its use is expanding rapidly. These land treatment facilities offer the
potential of producing an end product which is of the same or higher
quality than output from a conventional tertiary sewage treatment facility,
while at the same time offering the advantage of recycling nutrients in the
wastewater into usable food and fiber. This advanced treatment is often
achieved at much lower costs than the more conventional advanced technology.
Since land treatment technology is relatively new in the Great Lakes
Basin, many questions about management alternatives for such systems exist
as well as questions about safety from both a health and an environ-
mental standpoint. For example, land application diffuses a point source
so that it becomes a non-point pollution source. It also increases the
recharge of groundwater with this reclaimed wastewater. Thus, this tech-
nology must be subjected to a thorough evaluation in a critical and search-
ing manner before it is even more widely adopted. At the same time, manage-
ment alternatives for operation of such systems, if they prove feasible,
must be developed so that the designer and operator of such systems can
evaluate the various trade-offs associated with each management alternative.
Conclusions stemming from the Felton-Herron Creek Studies in this
regard can be summarized as follows:
Overall the oldfield and cropland sites resulted in discharges
of nutrients greater than non-irrigated sites. Proper selection of
vegetation, of irrigation rate and of harvest management would minimize
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discharges of N and P. Removal of vegetative material would minimize
reliance of the sites capacity to retain the nutrients against the
recharge flow.
Several general conclusions can be made. These include:
(1) The type of crop selected is very important in management of
land irrigation systems for the prevention of NO.,-N losses.
a.) Annuals such as corn do not take up much N during the
early part of the growing season. Thus, such crops should
be irrigated at rates that will just replace evapotrans-
pirational losses (about 2.5 cm/week in Michigan) for the
early growth period with increased irrigation up to 7.5 cm/
week after about the first five to seven weeks of growth.
b.) Perennial grasses are the most effective cropped vegetation
at removing N from wastewater. Harvesting can extend active
uptake through October. Thus, effective N removal by vege-
tative uptake can be expected from April through October
with proper managements with rates up to 10 cm/week of
wastewater application.
c.) Legumes such as alfalfa are about as effective as perennial
grasses at N removal except that irrigation should be
limited to 2.5 cm/week for a three week period after har-
vest since uptake is reduced during this period.
d.) Oldfield vegetation is very effective at removing N from
wastewater. Harvesting can extend active uptake through
October. Oldfield vegetation is as effective as perennial
grasses at removing N from wastewater. Mowing without
harvesting for grasses and probably for oldfield vegetation
is just as effective at extending the active uptake of N
through October at least through the first few years of
spray irrigation. If the system were not harvested, ulti-
mate breakthrough of both N and P would be expected. If
one wanted to build up the organic content of the soil,
mowing could be used for the first several years, followed
by harvesting after that.
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(2) Soils are effective at P sorption so that P concentrations of
water leaching past the root zone on irrigated sites approaches
background levels. Thus, groundwater loading with P is a func-
tion of leachate quantity but concentrations are low enough that
there are no problems with groundwater contamination.
(3) Runoff from spray sites should be avoided. Tiles draining such
sites often have direct surface connections through sand lenses
which lead to discharge of water with P concentrations over one
mg/£ during some actual spray events. These peak concentrations
are of short duration and drop rapidly as actual irrigation
ceases. On a mass balance basis, such high concentrations
account for only a small percentage of discharged water and P
removal by tiled systems is high (over 80%).
(4) Late successional beech-sugar maple forests are not efficient
at removal of N from wastewater. Such mature forests should not
be used for wastewater renovation since nitrate-nitrogen leaches
to groundwater at about input concentrations.
(5) Winter wastewater spray irrigation in the Great Lakes Basin is
feasible. The accumulated ice layer insulates the soil, prevents
it from freezing, and allows infiltration of water during winter
months. Since vegetative uptake mechanisms are not active,
applied inorganic nitrogen will ultimately leach through to
groundwater or runoff. Thus, winter spray irrigation of waste-
water should only be done with wastewater that is low in inor-
ganic nitrogen (e.g., from storage lagoons where summer plant
activity has stripped nitrogen by raising the pH above the pK
of ammonia gas). The early spring ice melt period is charac-
terized by high levels of phosphorus in runoff since the sat-
urated soil does not allow infiltration. This runoff could
be controlled by diking to retain the water on-site until it
infiltrated.
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MILL CREEK
It would appear that the predominant factor affecting the appearance
of pesticide problems in the Great Lakes is the nature of the chemical
formulation of the pesticide itself. Persistent compounds such as the
chlorinated hydrocarbons are still being transported to the lakes despite
their lack of use for several years in the watershed. Transport of these
compounds is tied closely with the movement of suspended sediments, thus
measures to control sediment movement would also control the movement of
chlorinated hydrocarbons. The problem in the lakes however, is apparently
slowly improving as these compounds reach their ultimate sink in some
unavailable compartment of the ecosystem or as they are degraded into
more harmless forms. In short, this problem should take care of itself
in time assuming no further use of these compounds.
Pesticide losses from Mill Creek in order of amount lost were DDT,
DDE, Atrazine, Dieldrin, ODD, Simazine, and Guthion. The sediment and
water were analyzed for 49 other pesticides; no appreciable amounts were
detected. Most pesticides such as the chlorinated hydrocarbons that were
lost, were associated with past farming practices. Of the pesticides cur-
rently in widespread use in the Mill Creek watershed, Atrazine and
Guthion do appear in Mill Creek. Their significance as a problem in the
Great Lakes is unclear at this time.
-------
SECTION 3
RECOMMENDATIONS: IMPLICATIONS FOR REMEDIAL MEASURES
FELTON-HERRON CREEK
The application of secondary municipal effluent on land offers a
viable, economically attractive alternative to conventional, tertiary
treatment technology, especially for small to medium sized cities where
land is available. Such land application will work for a variety of
cropped and non-cropped ecosystems providing proper management techniques
are used. These proper management techniques involve selection of a site
with infiltration rates of 5 cm/week or better and preferably with soils
with sufficient clay and organic content to serve as sorption sites for
P, heavy metals, etc. Assuming the proper site is selected, proper
management techniques include: (1) selection of the vegetation type to
give maximal wastewater cleanup at the lowest possible cost, and (2) sel-
ection of the harvest regime to maximize nutrient uptake and removal. In
this regard, the following vegetative types offer most potential:
(1) Perennial grasses and oldfield vegetation offer the
best phosphorus and nitrogen removal potential; however,
they offer least economic return. Such systems can
renovate from 7.5 to 10 cm/week of secondary effluent.
(2) Alfalfa offers excellent renovation potential, but
wastewater application should be limited to evapotrans-
pirational losses for the first three weeks following
each harvest since the system is subject to nitrogen
breakthrough during that period. At other times,
the irrigation rate can be as high as 7.5 cm/week
with no problem.
(3) Annuals such as corn are excellent at removing N and P
from as much as 7.5 cm/week of wastewater after the
8
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first five to seven weeks of growth. Annuals are
subject to losses of N and P in leachate during the
attainment of significant root biomass (five to
seven weeks for corn), and irrigation should be
limited to evapotranspirational losses during
that period. Annuals also cease active uptake
earlier in the fall than do perennial grasses and
oldfield vegetation.
(4) Older forests remove very little N from wastewater and
leachate from such sites often exceeds drinking water
standards for nitrate. Older forests should not be
used for application of "typical" secondary effluent.
They do offer excellent phosphorus removal and infil-
tration capacity for wastewater low in inorganic N.
Such low inorganic nitrogen wastewater is available
from the third or fourth cell of most lagoon systems
due to N stripping processes brought about by plants
in the lagoons. Plantations of young, fast growing
trees with grasses between tree rows are effective
at renovation of "typical" secondary effluent.
Selection of the proper harvest regime is also important in limiting
nutrient losses from land application systems. Experiments on this project
demonstrated the following:
(1) Harvesting grasses or oldfield vegetation extends the
active growth and nutrient uptake period through
October. Thus, these systems are effective at N and
P removal from April through October in Michigan.
(2) Mowing was as effective as harvesting in maintaining
growth of grasses through October. It was also as
effective as harvest in preventing nutrient losses;
however, eventual breakthrough would likely occur
if vegetation was not harvested for several years.
(3) Two harvests of oldfield vegetation per year (June
and September) removed the most nutrients. This
-------
nutrient removal accounted for essentially all of the
N added in wastewater and most of the P. One harvest
in June only resulted in extension of the growth
period through October but less N was removed in bio-
mass than was applied.
Some other findings which have important implications for management
of wastewater land application systems are:
(1) Tile drain systems result in peak discharges of P that
are greater than one mg/£. These peak losses occur as
a result of sand lenses or direct connections to the
tiles. Such losses are short-lived and represent only
a small fraction of P applied in wastewater. Never-
theless, avoidance of tile systems would result in
lower P losses in runoff.
(2) Water-logging an older forested site apparently pro-
moted rapid denitrification and resulted in ground-
water leachate low in inorganic N. However, runoff
losses of inorganic N and P were very high in this
study. If such sites could be water-logged without
significant runoff losses, excellent nitrogen removal
could be obtained. The intensive management needed
for such a system means that this technique probably
should not be widely adopted.
(3) Winter irrigation in Michigan is feasible. Insulation
by the accumulated ice-pack keeps the ground from
freezing and results in excellent winter infiltration.
However, nitrate-nitrogen losses to groundwater will
exceed the drinking water standard if "typical" sec-
ondary effluent is applied. Such winter application
could be used for irrigation from storage lagoons
which have low N water as a result of in-lagoon pro-
cesses. This application of water from lagoons would
lower the winter storage requirements for land appli-
cation systems. The first spring runoff from such
10
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winter spray systems is high in P because of freeze
out processes and saturated ground causing overland
flow. Thus, diking to retain such water on the site
would be needed.
In conclusion, land application systems for recycling secondary
municipal effluent offer an excellent alternative to conventional tertiary
treatment for small to medium sized communities. Such systems will
require rather precise management and, thus, will require trained per-
sonnel to operate efficiently. Efficiently operated systems are better
than conventional tertiary systems since little, if any, discharge to
surface water need occur. Thus, these systems meet the zero discharge
requirements for surface waters and, at the same time, offer a means of
replenishing the dwindling groundwater supplies with good quality water.
MILL CREEK
The major pesticide losses from the Mill Creek watershed are still the
chlorinated hydrocarbons which have not been used for several years. Most
of these pesticides are lost as a result of soil erosion and transport of
existing stream sediments. Thus, remedial actions would have to include
efforts to reduce soil erosion. The problem in the Great Lakes, however,
is apparently slowly improving as these compounds reach their ultimate
sink in some unavailable compartment of the ecosystem or as they are
degraded into more harmless forms. In short, this problem should take
care of itself in time assuming no further use of these compounds.
Of the currently used pesticides, Atrazine and Guthion do appear in
Mill Creek. Both are transported predominantly on sediments. Thus, reme-
dial actions that limited soil erosion would reduce loading of these com-
pounds. Atrazine is fairly persistent in soils (300-500 days) and repre-
sents the greatest contribution of any currently used pesticide from the
Mill Creek watershed. The significance of either Atrazine or Guthion in
terms of an environmental problem to the Great Lakes is unknown. Misuse
and accidents with pesticides can be expected no matter how strict a parti-
cular set of regulations is enforced. The only safeguard under these cir-
cumstances is to ban the manufacture and use of formulations that could
cause long term problems in the event of a single accidental introduction.
11
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Suspended sediment losses from the Mill Creek watershed are already
low compared to other midwestern watersheds. Nutrient losses are comparable
to losses from other agricultural watersheds in the Great Lakes Basin.
In conclusion, losses of pesticides, nutrients, and sediments from
the Mill Creek watershed are not excessive compared to other watersheds
in the Great Lakes Basin. Thus, no immediate remedial actions are recom-
mended. Long term remedial actions that should be pursued include adop-
tion of best management practices aimed at further reducing sediment losses
and adoption of integrated pest control programs which further reduce pes-
ticide use in the watershed.
12
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SECTION 4
INTRODUCTION TO FELTON-HERRON CREEK WATERSHED STUDIES
Recent laws have mandated consideration of land application systems
as an alternative to more conventional waste treatment facilities. Land
irrigation for treatment of municipal wastewaters occurs on only a small
percentage of land area in the Great Lakes Region. In Michigan, for
example, 40 small communities ranging in size from 100 to 6,600 persons
are presently utilizing some form of land irrigation. These 40 small com-
munities serve a combined population of over 59,000 people. In addition,
the Muskegon system serves a total population of over 79,000 people. Thus,
land treatment of municipal effluent is already used for nearly 140,000
people in Michigan alone, and this technology is expanding as other small
communities adopt it. While land treatment of wastewaters has been shown
to effectively lower nutrient concentrations to levels comparable to or
lower than those achieved by conventional waste treatment facilities, the
impact of diffusing these point sources to non-point sources and the impact
of various vegetation management schemes on these non-point discharges
through field tiles, seepages, runoff, or groundwater recharge has not been
well documented. In studies at Michigan State University, the impacts of
various irrigation and vegetative management schemes on discharge of phos-
phorus and nitrogen to streams and groundwater in the Great Lakes Region
have been investigated. These studies form the core of the Felton-Herron
Creek "Watershed" study.
The general objectives of the Felton-Herron Creek portion of the study
were to (1) develop management and design criteria to minimize surface and
subsurface water contamination in wastewater irrigation systems, and (2)
arrive at reasonable pollutant loading values associated with these prac-
tices.
13
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DESCRIPTION OF STUDY AREA
The Felton-Herron Creek study was located on the Water Quality Manage-
ment Facility (WQMF) on the Michigan State University campus near East
Lansing, Michigan. The project location is in the Red Cedar River water-
shed, a tributary to the Grand River which enters Lake Michigan at Grand
Haven, Michigan. The exact location of the WQMF is 42°43' 50" north
latitude and 84°28' 58" longitude or T4N, Rl, 2W, sees. 1, 6, 31, 36,
Ingham County, Michigan.
Basically, the Water Quality Management Facility consists of two ele-
ments: (1) a series of four man-made lakes with a total surface area of
16 ha and a mean depth of 1.8 m which receives secondary effluent, and
(2) a 58 ha tract of land used for spray irrigation of wastewater (Figure
4-1). The total area of the spray site is 127 ha when aerosol buffer zones
are included.
The Water Quality Management Facility received secondary effluent via
pipeline (Figure 4-1, A) from the City of East Lansing's conventional
extended aeration, activated sludge wastewater treatment facility at a
3
rate of 1975 m /day during 1977 (January 1 to October 28). About 39% of
this 594,335 m of water was spray irrigated, another 39% was discharged
via Felton Drain and the remainder was lost by evaporation or deep seepage
(TABLE 4-1). The total amount irrigated on the various ecosystem types
(Figure 4-2) is listed in TABLE 4-2. All irrigated wastewater was a mix-
ture of secondary effluent directly from the pipeline from the East Lansing
Sewage Treatment Plant and water that back-siphoned into the pipe from
Lake 1 (Figure 4-1) as a result of the rapid withdrawal rate from the pipe
during irrigation. All water was chlorinated prior to spray irrigation.
Application rates on all land study areas in 1976 was similar to 1977.
o
However, an additional 1215 m /day of wastewater were received in 1976 with
corresponding greater lake throughput and discharge to Herron Creek (Figure
4-1, C) until August 26 or to Felton Drain (Figure 4-1, D) thereafter.
Studies partially or completely funded as part of the Pilot Watershed
Studies of IJC include crop and grass management plot studies (Figure 4-2,
A), baseline watershed studies (Figure 4-2, B), forest studies (Figure 4-2,
D, E, and an area east of E), oldfield studies (Figure 4-2, G, H, I) and
14
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Figure 4-1. Looking northwest at Lakes 1, 2, 3, and 4. 'A' is the influent pipeline, 'B' is the
outlet from Lake 4, 'C' is the Herron Creek drain, 'D' is Felton Drain, 'E' is mature
woods, 'F' is field crops, and 'G' is a tree plantation.
-------
Figure 4-2. Photograph of the Spray Irrigation Area showing major research areas. Area 'A' is the
crop and grass management plot; 'B' is the baseline watershed; 'D1, 'E' and the area
east of 'E' is the forest study area; 'G', 'H' and 'I' constitute the site of the old-
field studies; 'K' is the winter irrigation area; and 'F' is a tree plantation.
-------
TABLE 4-1: SUMMARY OF WATER FLOWS FOR THE WATER QUALITY MANAGEMENT
FACILITY, JANUARY 1 TO OCTOBER 28, 1977
Amount Percent of
(cubic meters) Total Input
Wastewater Input 594,335 100.0
Discharge to Felton Drain from Lakes 233,093 39.2
Lake Evaporative and Seepage Losses 130,621 22.0
Spray Irrigation 230,621 38.8
TABLE 4-2: SUMMARY OF WASTEWATER IRRIGATION ON THE LAND SITE FOR 1977
(JANUARY 1 TO OCTOBER 28)
Amount
Study Area (cubic meters)
Crop Plots
5 cm/week Mature Forest Plot
10 cm/week Mature Forest Plot
5 cm/week Oldfield Plots
10 cm/week Oldfield Plots
5 cm/week Oldfield Winter Spray Area
Tree Plantation
Other
TOTAL
19,700
19,555
39,110
23,404
45,172
39,621
34,518
9,541
230,621
Percent of
Total Input
8.5
8.5
17.0
10.2
19.6
17.2
15.0
4.1
100.0
winter spray studies (Figure 4-2, K). Also, studies of water quality and
nutrient loadings at stations upstream and downstream of the entire land
spray site were conducted in Felton Drain (Figure 4-1, D). Methods,
results, discussion, and conclusions from each of the studies will be pre-
sented in Sections 5 to 9.
The soils on the spray irrigation site are highly variable both verti-
cally and horizontally. The soils have been mapped using high intensity
sampling with a 55 m sampling grid (Figure 4-3, TABLE 4-3).l There are 19
soil types but the predominant soil types are loam, sandy loam, or loamy
sand. Hydraulic limitations of the site vary from 0 to over 20 cm/week
with the average limit being 5 cm/ha/week. Overall, these soils have
17
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1-96
LEGEND
oo
WQMP Irrigolion Area Boundary
V Sand Spot
T/ljC' Clay Spot
Y"* Wet Spot
Sandhill Road
Organic Soil Area
>
Drain
Pond
High Intensity
IWR Map 1975
1 Brookston
2 Miami-Marlette
3 Conover
4 Fox
5 Granby
6 Barry
7 Corunna
8 Westland
9 Kalamazoo
10 Owosso
11 Metea
12 Spinks
13 Matherton
14 Hillsdale-Dryden
15 Lamson
16 Sisson
17 Kidder
18 Sebewa
19 Colwood
A Slopes 0-2%
B Slopes 2-6%
C Slopes 6-12%
D Slopes 12-18%
;;;• slopes 18%
/jr.* or !%N~T} Intermittent Pond
m * •»»•«•
2\ Soil Boundaries
Figure 4-3: Soil map of the spray irrigation site.
-------
TABLE 4-3: GENERAL SOIL DESCRIPTION OF THE SPRAY IRRIGATION SITE
VO
Map
Symbol* Soil Name
GENERAL SOIL DESCRIPTION
Surface Soil
Subsoil
Underlying Materials
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Brooks ton
Miami-Marlette
Conover
Fox
Granby
Barry
Corunna
West land
Kalamazoo
Owosso
Metea
S pinks
Matherton
Hillsdale
Lams on
Sisson
Kidder
Sebewa
Colwood
Loam
Loam
Loam
Loam
Loamy sand
Sandy loam
Sandy loam
Silty clay
loam
Loam
Sandy loam
Loamy sand
Loamy sand
Loam
Sandy loam
Fine sandy
loam
Fine sandy
loam
Clay loam
Loam to sandy
loam
Loam
Clay loam
Clay loam
Clay loam
Gravelly clay loam to sandy
clay loam
Fine sand
Sandy clay loam
Sandy loam
Clay loam to gravelly clay loam
Gravelly clay loam to sandy
clay loam
Sandy loam to sandy clay loam
Loamy sand to sand
Loamy sand to sandy loam
Gravelly loam to sandy clay loam
Sandy clay loam to sandy loam
Fine sandy loam to silt loam
Silt loam to silty clay loam
Sandy clay loam
Gravelly sandy clay loam to
clay loam
Silt loam to silty clay loam
Loam to silt loam
Loam to silt loam
Loam to silt loam
Sand and gravel
Sand to fine sand
Sandy loam
Loam to clay loam
Gravel and sand
Sand and gravel
Loam to clay loam
Loam to clay loam
Sand
Sand and gravel
Sandy loam to loamy sand
Fine sand to loamy very
fine sand
Very fine sands and silts
Gravelly sandy loam
Sand and Gravel
Very fine sands and silts
See Figure 4-2.
-------
excellent phosphorus sorption capabilities. As calculated from the soils
map and data given by Schneider and Erickson,2 at least 1600 kg/ha of phos-
phorus could be sorbed by the first 0.9 m of soil without any vegetative
removal. Thus, this site has infiltration and phosphorus sorption charac-
teristics suitable for land application of wastewater.
GENERAL STUDY APPROACH
The spray irrigation site was intensively monitored for surface runoff
at several points along the main drain and its tributaries (Figure 4-4).
Water quality was monitored at stations UNFD 02, UNFD 10 (Felton Drain
upstream and downstream of the spray site), at station UNFD 13 (output from
the baseline watershed), at station UNFD 14 (output from forest sites), at
station UNFD 04 (tile drain output from oldfield studies), and at UNFD 06
(output from the winter spray areas).
The conceptual basis for the monitoring approach to the Felton-Herron
watershed study was shaped by the two types of hydrologic events experienced
in this watershed. Events either resulted from natural processes (rain and
snow melt) or from wastewater irrigation. Monitoring of runoff from indi-
vidual irrigation sites (UNFD 04, UNFD 06, UNFD 13, UNFD 14 ~ Figure 4-4)
was expected to delineate specific source loadings from each type of waste-
water irrigation management used (see Sections 5 to 9). These specific
studies were to be coupled with studies of runoff from the main channel
representing an integration of all loads from the site. The main channel
Felton Drain studies included an input station, UNFD 02 (Figure 4-4), which
drained an upstream 54 ha area of mixed crop and pasturelands plus runoff
from a series of poultry barns which make up Michigan State University's
Poultry Production/Research Station. Poultry manure from these barns was
spread over the surrounding grounds as fertilizer resulting in high inputs
to Felton Drain. The output station, UNFD 10 (Figure 4-4), included the
actual spray irrigation site, part of its aerosol buffer zone, and runoff
from a 36 ha area of an interstate highway, 1-96.
The results from the main channel Felton Drain studies were not con-
clusive for the following reasons. First, the inputs to the site were high
and very variable because of the manure spreading associated with the
20
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Figure 4-4: Location and station designation of existing water quality monitoring points. Sampling
stations enclosed by a rectangle denote location of recording stream gauging stations.
-------
upstream poultry production/research facility. Second, the total area
irrigated during this study (12.6 ha) was less than 15% of the 84 ha total
area drained by the output station after inputs from the 54 ha upstream
station were subtracted. Third, inputs from the 36 ha highway drainage
area to the total 84 ha downstream area were not monitored and could have
contributed substantial amounts of some constituents (e.g., chloride from
winter salting operations). Fourth, the output from the 16 ha wastewater
lake system of the Water Quality Management Facility was diverted down
Felton Drain in August, 1976, before the first complete year of sampling
was completed. Fifth, low flow samples were highly variable as a result
of the various processes occurring in the watershed, resulting in large
errors associated with low flow loadings. These large errors resulted from
the relatively few low flow samples taken since event sampling was empha-
sized, and since concentrations of constituents in stream discharge were
highly variable. Also, stream flow sometimes resulted from wastewater
irrigation only, from lake discharge only, from rainfall generated runoff
only, or from a combination of two or more of the preceeding. As a result
of the many variables included in the main drain sampling program and as
a result of the high errors associated with loading estimates of low flow
from the output station, these studies did not result in useful data. Pre-
liminary estimates for the input and output stations were included in the
recent summary pilot watershed report.3 They and runoff from the specific
irrigation areas have been recalculated using the Beale ratio estimator
technique adopted for IJC studies. Estimates were made for each season
by treating the rising limb of each runoff event as one stratum, the fall-
ing limb as a second stratum, and each daily low flow sample as a stratum,
then using these strata to estimate total seasonal loads. The non-event
strata of the output station are characterized by large errors as discussed
above. The input-output data for the main drain will not be presented here
since they appear to be meaningless. They are available upon request from
T.M. Burton. Runoff and groundwater recharge from specific wastewater man-
agement activities will be discussed in detail in the following sections
(Sections 5 to 9). Precipitation inputs were also measured with rain
gauges at sites in the center of the spray irrigation site and on the east
22
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and west ends of the site. These data are incorporated in the mass balances
presented in the following sections (Sections 5 to 9).
23
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REFERENCES
1. Zobeck, T.M. The Characterization and Interpretation of a Complex
Soil Landscape in South-Central Michigan. M.S. Thesis, Michigan State
University, East Lansing, Michigan, 1976. 121 pp.
2. Schneider, I.F. and A.E. Erickson. Soil Limitations for Disposal of
Municipal Waste Waters. Research Report 195, Michigan State Univer-
sity Agricultural Experiment Station, East Lansing, Michigan, 1972.
54 pp.
3. Bahr, T.B. Summary Pilot Watershed Report, Felton-Herron Creek,
Mill Creek Pilot Watershed Studies. International Joint Commission,
Reference Group on Pollution from Land Use Activities, Task C
Technical Committee Report. International Joint Commission, Great
Lakes Regional Office, Windsor, Ontario, 1978. 48 pp.
24
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SECTION 5
LAND APPLICATION OF MUNICIPAL EFFLUENT ON OLDFIELDS AND ON GRASS LANDS
James E. Hook and Thomas M. Burton
INTRODUCTION
Land application can be a practical means of recycling the nutrients
in municipal wastewaters if such systems are harvested. While wastewaters
may be safely applied to non-harvested areas, such application must even-
tually result in a buildup of waste constituents until annual leaching,
runoff or gaseous loss of those constituents equals annual application.
Such sites may be successful if waste constituents are diluted by rainfall
and groundwater to safe levels or if they are decomposed (e.g., organic
matter, nitrate) to gaseous forms or if potential storage capacity is much
higher than annual application rates thus assuring a reasonable life of
the system.
Under most conditions, sustained use of a wastewater renovation site
will require removal of some or all of the nutrients by plant harvest. To
the operator of the waste application site, any harvest or other manipula-
tion of the site represents an added expense. Justification for this addi-
tional manipulation of the site comes from a) direct return ~ sale of
feed or fiber products produced, b) indirect — extension of the life of
the renovation site and/or production of an environmentally acceptable or
legally mandated water quality. These costs and returns are impossible to
evaluate unless the interaction of various crops and cropping systems of
various wastewaters and application methods and of various soils and hy-
draulic conditions are known or predictable. Seitz and Swanson, Evans,
Melsted3 and many others have pointed out that we do not now have the
ability to predict very many of the alternatives in land application of
wastewater. The very dilute nature of the nutrient source and the gener-
ally high irrigation rates of land application systems make it difficult
25
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to extend conventional agricultural fertilization and irrigation knowledge
to these systems. Further, very little is known of the effects of cropping
and wastewater irrigation on the quality of leachate and runoff. Only
through integrated studies of wastewater irrigation-cropping and non-
cropping systems will the parameters needed to make least cost predictions
of renovating wastewaters be available.
In a previous study of oldfield irrigation, Hook and Kardos4 showed
that an unharvested oldfield could effectively lower nitrate concentrations
when irrigated at 5.0 cm/week during the growing season. When the irriga-
tion rate was increased to 7.5 cm/week, nitrate leached from the site at
concentrations greater than 10 mg N/A. By subsequently lowering the weekly
rate back to 5.0 cm/week, the leachate concentration decreased to accept-
able levels.5 The effectiveness of this oldfield for N renovation was
greater during the first eight years than for the last three years of the
14 years of effluent additions. This may have been due in part to lack of
harvest since the vegetation had changed from an open oldfield with a few
small trees to what more closely resembled an early successional forest.6
When an effluent irrigated forest area was clear-cut, volunteer vegetation
again proved effective in controlling nitrate leaching.5
Previous studies on grass fields irrigated with municipal effluent
have usually dealt with harvested areas. 7~1:L All have reported excellent
retention of N and adequate removal in the harvested grass to prevent ex-
cessive nitrate leaching. The effectiveness of the grass under simple
management schemes remains to be evaluated.
The purpose of this study, then, was to develop choices of vegetative
management for land application systems. Specifically, it compared several
methods of managing grasses and oldfield vegetation with respect to
leaching of nitrate and other major nutrients.
MATERIALS AND METHODS
Site Description
The two different sets of experiments in this study included experi-
ments on a planted grass site and experiments on volunteer oldfield vege-
tation. Vegetation on the planted site was 'Park1 Kentucky bluegrass
26
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(Poa pratensis, L.) established in 1973 and mowed periodically in 1974 and
1975. In 1976, twelve 10 x 10 m plots were established in four blocks of
three cutting treatments each. The cutting treatments were: 1) harvest
as hay three times annually, 2) mow biweekly leaving the vegetation on the
site, and 3) no cutting. The plots had been irrigated with secondary
municipal effluent at an average of 5.0 to 6.3 cm/week during the growing
season of 1974 and 1975. They were irrigated at 7.5 cm/week (0.83 cm/
hour for three hours, three days per week) from April 28, 1976 to October 8,
1976 and from May 11, 1977 to July 15, 1977. The soil at the site was a
Miami loam, a member of the fine-loamy, mixed mesic family of Typic
Hapludalfs, and was developed on silt to loam glacial till. The soil was
well drained.
The second experimental site was an oldfield that had been abandoned
from corn cultivation approximately 10 years earlier. The predominant vege-
tation on this site was Solidago sp., Agropyron repens, Aster sp., Taraxacum
officinale, and Poa compressa. The site was divided into three irrigation
treatment areas (0, 5, and 10 cm/week). The site had been irrigated with
secondary municipal effluent in 1975. It was not harvested in 1975. In
1976, the previously irrigated areas were divided into four blocks for a
complete block design. Each block contained six plots with randomly as-
signed treatments. These treatments were: irrigation rates of 5 and 10
cm/week; and cutting managements of zero, one (June) and two (June and
September) harvests for each irrigation rate. In addition to the irrigated
blocks, two non-irrigated control blocks of six plots each were established
with the three cutting managements duplicated within each block. Each
treatment plot was approximately 0.07 ha with a smaller area in the center
of the plot used for monitoring nutrient changes in soil and soil-water.
The irrigated plots were sprayed at 5.0 cm/week (0.83 cm/hour for three
hours, two days per week) or at 10.0 cm/week (0.83 cm/hour for six hours,
two days per week) with Buckner 8600 agricultural spray heads from April
19 to October 22, 1976, and from April 18 to October 27, 1977. The waste-
water applied was a mixture of secondary effluent directly from East
Lansing, Michigan or water that had back-siphoned from the first of four
receiving lakes. Wastewater was chlorinated prior to application.
27
-------
The soils at this oldfleld site were the Miami silt loam described
above and the Fox sandy loam, a member of fine-loamy over sandy or sandy
skeletal, mixed, mesic family of Typic Hapludalfs. The Fox soil like the
Miami was well drained. It was formed in loamy outwash overlying strati-
fied calcareous sands and gravels.
Sampling and Analyses
Wastewater was sampled from each application with acid washed poly-
ethylene funnel collectors placed 1.5 m above the ground. Soil-water was
sampled using porous cup vacuum type tube lysimeters evacuated to 0.8
atmospheres immediately before one weekly irrigation and sampled 48 hours
later. In the bluegrass site these lysimeters were placed with the cup
at 15 and 150 cm below the surface and with small diameter tubing connect-
ing the cup with the sample vacuum chamber located above ground. In the
oldfield site, the lower cup and vacuum chamber were at the 120 cm depth.
No surface runoff was seen at either site when irrigated at the 0.83
cm/hour rate. There was some tile drainage from an existing tile system
from the oldfield site. This tile drainage was sampled with an ISCO se-
quential sampler for a limited number of events in 1976. In 1977, events
were sampled with the sequential sampler every other week; these samples
were supplemented by 5-10 grab samples each week. Rainfall was measured in
four recording rain gauges located within 1.2 km of the sites. Wastewater
application was calculated from pumping records and was verified with 52
plastic rain gauges in the irrigated plots. Evapotranspiration and re-
charge were calculated using Thornthwaite and Mather's technique.12
Plant biomass was measured at two to four week intervals at both
sites during the growing season. In the oldfield, four 0.25 m2 quadrats
were sampled in each plot. All vegetation above the ground surface was
removed, sorted to species, segregated into living and litter components,
dried in an oven at 70 C, weighed for biomass determination, then ground
in a Wiley Mill and subsampled for subsequent tissue analysis of N and P.
f\
In the grass plots, three 0.25 m quadrats were sampled in each plot. All
vegetation standing above the normal cutting height (5 cm) in these grass
plots was removed for biomass determination. In 1976, the quadrat samples
in the oldfield were supplemented by yield estimates which were made by
28
-------
weighing all vegetation cut in a 0.84 x 9.1 m strip with a sickle bar
mower. Yield data for 1976 agreed closely with biomass estimates made
from the four quadrat samples; therefore, only quadrat data were used in
1977.
Nitrate and ammonium in all water and soil-water samples were
determined by ion-selective electrodes13'14 in 1976 and by distillation
in 1977. Kjeldahl-N was determined on monthly soil-water composites and
on all effluent samples by semi-microkjeldahl digestion followed by
distillation. Chloride was determined by ion-selective electrode, Na and
K were determined by emission spectroscopy, and Ca and Mg were analyzed by
atomic absorption. Oldfield plant samples were analyzed for Kjeldahl plus
nitrate N by semi-microkjeldahl digestion17 followed either by NH3 deter-
mination by ammonium electrode or by distillation. Total plant P was
measured in the microkjeldahl digest by the vanadomolybdophosphoric acid
colorimetric method.18 Soil samples were analyzed for nitrate, ammonium,
and chloride extracted from wet samples with IN K2SC>4 (approximately a 1:5
soil:solution ratio)19; for Na, K, Ca, and Mg extracted with IN NH4OAc
(1:8 soil:solution ratio)20; and for available P extracted with dilute
21
acid-fluoride (1:8 soil:solution ratio) and analyzed by the colorimetric
22
method.
RESULTS AND DISCUSSION
Bluegrass Cutting Management
The major nutrients added in 1976 and 1977 (TABLE 5-1) were made in
approximately equal, weekly increments throughout the growing season.
Based upon total annual loadings, no nutrients should be limiting for
growth of bluegrass.
The growth of the bluegrass increased with cutting. The dry weight
of new biomass above the cutting height (5 cm) increased from an average
of 20.8 kg/ha/day with no cutting to 34.2 and 44.9 kg/ha/day with hay
harvest and mowing, respectively, during 1976. The increase in rate of
growth should have been accompanied by an increase in the rate of nutrient
uptake resulting in a decreased probability that nutrients in wastewater
would leach past the root zone.
29
-------
TABLE 5-1. MEAN ANNUAL CONCENTRATION AND TOTAL AMOUNTS OF WASTEWATER
CONSTITUENTS APPLIED TO THE GRASS MANAGEMENT SITE FROM 7 5 cm/
WEEK OF WASTEWATER IRRIGATION
Effluent Concentrations
(mg/£)
1976 1977
N03-N
NH4-N
Total N
Total P
K
Ca
Mg
Na
12.11
1.68
15.30
2.68
10.4
79.7
25.8
88.8
8.50
1.51
11.72
2.72
10.4
57.6
25.3
98.3
Amount Applied
(kg/ha)
1976 1977
214
30
272
48
189
1363
449
1566
153
27
211
49
187
1037
455
1769
The amounts of nitrate in soil-water both in the root zone and below,
however, varied little with cutting or with time of year (Figures 5-1 and
5-2). Mineral N, nearly all nitrate, in both the root zone and at the 150
cm depth consistently remained below 10 mg N/A. Despite the fact that no
vegetation was removed from the no-cutting and the mowing plots, these
plots were as effective as the harvested plots in controlling N leaching
past the 150 cm depth.
The effectiveness of the no harvest plots can be explained by denitri-
fication and by immobilization of N in plant materials. The latter appears
unlikely in the case of mowed plots because the plant residues which fall
to the ground are rapidly incorporated and are likely mineralized as well.
On the other hand, denitrification has been observed under rapidly
growing grasses.23 Production of root exudates and decomposing organic
material could supply carbon for denitrification. Root respiration and
high moisture content due to the irrigation favors lowered oxygen content.
These conditions should be greatest in the mowed plots, because the average
biomass production rate was greatest and because all the residues were left
on the plot to decompose. The no-cut grass plots had the lowest average
30
-------
15
• NO CUT
• HAY
A MOW
o EFFLUENT
40 15 20
WEEKS
25 30
1977
35
40
Figure 5-1: Weekly average mineral N concentrations in applied effluent and in soil-water
from the 15 cm depth of the 7.5 cm/week irrigation rate on bluegrass managed
with various cutting treatments.
-------
u>
K!
40.
o> 30.
\
o>
^
-, 20J
cr
LU
10 _
o.
15
Figure 5-2:
• NO CUT
• HAY
A MOW
o EFFLUENT
1 1—
20 25 30 35 40 15 20 25 30 35
1976 WEEKS 1977
40
Weekly average mineral N concentrations in applied effluent and in soil-water
from the 150 cm depth of the 7.5 cm/week irrigation rate on bluegrass managed
with various cutting treatments.
-------
annual production rate. However, the productivity during the first three
months (4/27-7/13) of the growing season was similar to that of harvested
plots at 54.3 kg/ha/day. After mid-July, productivity declined, and the
amount of biomass present actually declined. As productivity slowed and
biomass declined and as plants decomposed, a mineralization-nitrification-
denitrification sequence may have prevented nitrate leaching.
Oldfield Cutting Management
The concentrations as well as the amounts of wastewater constituents
added to this site are given in TABLE 5-2. Most constituents were added
uniformly throughout the irrigation period. However, monthly N concen-
trations fluctuated as much as two-fold. This occurred because approxi-
mately 80% of the wastewater applied weekly was backsiphoned from the
first of the effluent treatment lakes rather than from the effluent pipe-
line. This backsiphoned water was thus subject to the N dynamics of the
lake.
TABLE 5-2. MEAN ANNUAL CONCENTRATION AND TOTAL AMOUNTS OF WASTEWATER
CONSTITUENTS APPLIED TO THE IRRIGATED AREAS OF THE OLD FIELD
SITE
Effluent
Concentrations
1977
1976
Amount Applied
(kg/ha)
5 cm/week
1976 1977
Amount Applied
(kg/ha)
10 cm/week
1976 1977
N03-N
NH4-N
Total N
Total P
K
Ca
Mg
Na
10.49
1.35
13.66
2.72
9.98
69.85
24.38
86.47
9.14
1.23
13.61
2.74
10.50
57.89
25.55
97.11
127
16
167
33
117
849
290
1024
122
16
182
37
141
776
342
1301
224
30
329
66
244
1700
596
2119
232
31
346
70
267
1470
649
2467
33
-------
As expected, the effluent irrigation increased dry matter production
of the harvested plots (TABLE 5-3). The N and P concentrations of the
plant tissue were also increased by irrigation at both the 5 and 10 cm/
week levels. Harvest of the vegetation in September as well as in June
increased the average annual total biomass removal by 78, 46, and 47% for
the 0, 5, and 10 cm/week irrigations, respectively. This second harvest
was also responsible for increasing the N removal by 76, 39, and 57%,
respectively, for the three irrigation rates (TABLE 5-3).
Nitrogen—
The effectiveness of the various treatments for controlling N leaching
can be seen by the annual N balances which were calculated for the 1976-
1977 water year (TABLES 5-4 to 5-6). When irrigated at 5 cm/week, the
amount of mineral N which leached past the 120 cm depth was less than 20%
of the added mineral N regardless of the harvest management used. When
the weekly irrigation rate was increased to 10 cm/week (TABLE 5-6) , the
mineral N which leached to the 120 cm depth made up 42, 26, and 31% of the
added N for the zero, one and two annual harvests. The harvests, either
once or twice, lowered the amount of N leaching by about 35% compared to
the unharvested treatment for this 10 cm/week rate.
The effectiveness of the oldfield vegetation, like the bluegrass
vegetation, can be explained in terms of the rapidly growing vegetation
which both immobilizes added mineral N and stimulates denitrification.
The plots harvested once during the year were harvested in June when
growth rate and total biomass were maximal. This biomass removed 77% of
the N added to the 5 cm/week plots and 52% of the N added to the 10 cm/
week plots. The second harvests remove biomass when the regrowth is maxi-
mal. The two harvest management removed 94% and 83% of the N added to the
5 and 10 cm/week plots, respectively. Thus, while the single harvest did
an adequate job of removing effluent N, two harvests assured that N would
neither build up at the site nor leach to the groundwater.
The unharvested plots on an annual mass balance basis, also proved
effective in preventing N leaching, particularly at the 5 cm/week level.
A possible explanation is denitrification occurring subsequent to maximum
34
-------
TABLE 5-3.
MEAN ANNUAL YIELD, N AND P CONTENT AND N AND P REMOVALS OF THE HARVESTED PLOTS OF THE
OLDFIELD SITE
Yield
Irrigation Harvest Dry Weight
Rate Metric tons /ha
0 cm/week One Cut 1976
1977
Average
Two Cuts 1976
1977
Average
5 cm/week One Cut 1976
1977
Average
Two Cuts 1976
1977
Average
10 cm/week One Cut 1976
1977
Average
Two Cuts 1976
1977
Average
3.16
2.30
2.73
5.24
4.49
4.87
4.50
6.73
5.62
7.59
8.76
8.18
5.18
8.08
6.63
7.88
11.65
9.76
Nitrogen
Content*
% Dry Weight
1.94
1.61
1.78
1.93
1.56
1.75
2.15
1.90
2.03
2.08
1.78
1.93
2.38
1.82
2.10
2.36
2.03
2.20
Nitrogen
Removal
kg/ha
61
37
49
101
70
86
97
128
113
157
156
157
123
147
135
187
237
212
Phosphorus
Content*
% Dry Weight
0.30
0.28
0.29
0.30
0.27
0.29
0.32
0.31
0.32
0.32
0.33
0.33
0.37
0.28
0.33
0.34
0.34
0.34
Phosphorus
Removal
kg/ha
9.5
6.5
8.0
15.6
12.0
13.8
14.4
21.1
17.8
24.2
29.1
26.7
19.2
22.6
20.9
26.9
39.7
33.3
For the two cutting management these are weighted average content.
-------
TABLE 5-4. MASS BALANCE FOR INORGANIC N FOR THE 0 cm/WEEK OLDFIELD SITE
(VALUES IN kg N/ha)
Month
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 77
July 77
Aug 77
Sep 77
ANNUAL
% Input
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 77
July 77
Aug 77
Sep 77
ANNUAL
% Input
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 7 7
July 77
Aug 77
Sep 77
ANNUAL
% Input
Precipi-
tation
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
100.00
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
100.00
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
100.00
• INPUT
Irri-
gation
***
0
0
0
0
0
0
0
0
0
0
0
0
0
0
AsVA*
0
0
0
0
0
0
0
0
0
0
0
0
0
0
****
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Total
•* N 0
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
100.00
ONE
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
100.00
TWO
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
100.00
Vegetation
Removal
H A R V E S
0
0
0
0
0
0
0
0
0
0
0
0
0
0
H A R V E S
0
0
0
0
0
0
0
0
37
0
0
0
37
166
H A R V E S
0
0
0
0
0
0
0
0
42
0
0
28
70
315
— OUTPUT -
Recharge
T ****
0.00
0.00
0.00
0.00
0.00
0.00
0.25
0.00
0.00
0.00
0.00
0.00
0.25
1.00
T *?VA*
0.00
0.00
0.00
0.00
0.00
0.00
0.14
0.00
0.00
0.00
0.00
0.00
0.14
1.00
T S ****
0.00
0.00
0.00
0.00
0.00
0.00
0.19
0.00
0.00
0.00
0.00
0.00
0.19
1.00
Retention
1.52
0.59
0.38
0.28
4.65
2.05
2.75
0.36
3.01
1.29
1.77
3.35
22.00
99.00
1.52
0.59
0.38
0.28
4.65
2.05
2.86
0.36
-33.99
1.29
1.77
3.35
-14.89
-67.00
1.52
0.59
0.38
0.28
4.65
2.05
2.81
0.36
-38.99
1.29
1.77
-24.65
-47.94
-215.00
36
-------
TABLE 5-5. MASS BALANCE FOR INORGANIC N FOR THE 5 cm/WEEK OLDFIELD SITE
(VALUES IN kg N/ha)
Month
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 7 7
July 77
Aug 77
Sep 77
ANNUAL
% Input
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 7 7
July 77
Aug 77
Sep 77
ANNUAL
% Input
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 77
July 77
Aug 77
Sep 77
ANNUAL
% Input
Precipi-
tation
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
13.00
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
13.00
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
13.00
T \TPTTT
- ±Nrul
Irri-
gation
***j
25.97
0.00
0.00
0.00
0.00
0.00
13.13
17.94
15.42
25.79
26.26
21.51
146.02
87.00
****
25.97
0.00
0.00
0.00
0.00
0.00
13.13
17.94
15.42
25.79
26.26
21.51
146.02
87.00
****
25.97
0.00
0.00
0.00
0.00
0.00
13.13
17.94
15.42
25.79
26.26
21.51
146.02
87.00
Total
* N 0
27.49
0.59
0.38
0.28
4.65
2.05
16.13
18.30
18.43
27.08
28.03
24.86
168.27
100.00
ONE
27.49
0.59
0.38
0.28
4.65
2.05
16.13
18.30
18.43
27.08
28.03
24.86
168.27
100.00
TWO
27.49
0.59
0.38
0.28
4.65
2.05
16.13
18.30
18.43
27.08
28.03
24.86
168.27
100.00
Vegetation
Removal
H A R V E S
0
0
0
0
0
0
0
0
0
0
0
0
0
0
H A R V E
0
0
0
0
0
0
0
0
128
0
0
0
128
77
H A R V E
0
0
0
0
0
0
0
0
75
0
0
81
156
93
- — OUTPUT
Recharge
T ****
7.02
0.94
0.54
0.35
0.50
1.35
3.32
0.98
0.30
1.00
1.44
11.10
28.84
17.00
S T ****
6.12
0.67
0.39
0.26
0.38
1.11
2.91
1.75
1.54
2.91
5.47
6.68
30.19
18.00
S T S ****
2.03
0.83
0.43
0.25
0.31
0.59
0.65
0.66
0.31
1.08
1.51
1.52
10.17
6.00
Retention
20.47
-0.35
-0.16
-0.07
4.15
0.70
12.81
17.32
18.13
26.08
26.59
13.76
139.43
83.00
21.37
-0.08
-0.01
0.02
4.27
0.94
13.22
16.55
-111.11
24.17
22.56
18.18
10.08
6.00
25.46
-0.25
-0.05
0.03
4.34
1.46
15.48
17.64
-56.88
26.00
26.53
-57.66
2.10
1.00
37
-------
TABLE 5-6.
MASS BALANCE FOR INORGANIC N FOR THE 10 cm/WEEK OLDFIELD SITE
(VALUES IN kg N/ha)
Month
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 7 7
July 77
Aug 77
Sep 77
ANNUAL
% Input
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 77
July 77
Aug 77
Sep 77
ANNUAL
% Input
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 77
July 77
Aug 77
Sep 77
ANNUAL
% Input
Precipi-
tation
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
8.00
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
8.00
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
8.00
— INPUT -
Irri-
gation
49.69
0
0
0
0
0
17.99
33.33
26.19
51.49
44.62
39.81
263.12
92.00
49.69
0
0
0
0
0
17.99
33.33
26.19
51.49
44.62
39.81
263.12
92.00
49.69
0
0
0
0
0
17.99
33.33
26.19
51.49
44.62
39.81
263.12
92.00
^
Total I
***# N 0
51.21
0.59
0.38
0.28
4.65
2.05
20.99
33.69
29.20
52.78
46.39
43.16
285.37
100.00
*ftft* ONE
51.21
0.59
0.38
0.28
4.65
2.05
20.99
33.69
29.20
52.78
46.39
43.16
285.37
100.00
**** TWO
51.21
0.59
0.38
0.28
4.65
2.05
20.99
33.69
29.20
52.78
46.39
43.16
285.37
100.00
Vegetation
lemoval
H A R V E
0
0
0
0
0
0
0
0
0
0
0
0
0
0
H A R V E
0
0
0
0
0
0
0
0
147
0
0
0
147
52
H A R V E
0
0
0
0
0
0
0
0
125
0
0
112
237
83
OUTPUT
Recharge
S T ****
35.7
1.6
1.0
0.7
1.0
3.2
14.0
9.1
2.3
7.3
10.8
32.5
119.2
42.0
S T ****
15.2
1.2
0.7
0.5
0.7
2.2
9.8
4.2
2.3
6.4
8.6
24.0
75.8
27.0
S T S ****
24.4
1.2
0.7
0.4
0.5
0.8
3.8
2.9
2.0
7.7
12.1
30.6
87.1
31.0
Retention
15.51
-1.01
-0.62
-0.42
3.65
-1.15
6.99
24.59
26.90
45.48
35.59
10.66
166.17
58.00
36.01
-0.61
-0.32
-0.22
3.95
-0.15
11.19
29.49
-120.10
46.38
37.79
19.16
62.50
22.00
26.81
-0.61
-0.32
-0.12
4.15
1.25
17.19
30.79
-97.80
45.08
35.29
-99.44
-38.73
-14.00
38
-------
growth rate. Growth rate of the vegetation during the period May 1 to
August 1, 1977 (weeks 17 to 30) was approximately 120 kg/ha/day. During
this period 220 kg N/ha would be taken up by plants containing 2% N. This
was higher than effluent N additions of 114 and 155 kg N/ha of the 5 and
10 cm/week rates. The additional N taken up would have to be supplied by
mineralization of the litter remaining from the previous year's treatment
and of native soil N. During this period, uptake can explain the low rate
of N leaching. After August 1, the growth rate of the annuals drops
sharply and net live biomass decreases. During this period, N needed for
flowering and seed filling could be supplied from within the plant. As
lower leaves drop off and decay, net additions of effluent and mineralized
N must far exceed the plant needs. During this period, denitrification
would probably have to occur to prevent excessive N leaching. Evidence for
denitrification is uncertain. The concentration of mineral N in soil-water
under the no harvest plots increases after about week 30, first in the top-
soil (Figures 5-3 and 5-4) then in the subsoil (Figures 5-5 and 5-6).
During this August to October period, unharvested plots were less effective
than harvested plots, yet the annual mass balance indicates that 58 to 83%
of the added N was either lost by denitrification or retained in the soil-
plant system.
Organic plus ammonium N was monitored in soil-water samples during
1976 (TABLE 5-7). There were no significant differences in concentrations
with either irrigation levels or irrigation managements. There was a
slight decrease with depth.
Phosphorus—
Orthophosphate in the soil-water was also measured during 1976
(TABLE 5-8). Variability was very high in samples taken from the topsoil,
particularly in the 10 cm/week plots. No significant differences were seen
with treatments. In soil-water from the 120 cm depth, orthophosphate con-
centrations were at background concentrations. Given the fine texture of
this soil and the annual loading rates, it was unlikely that the phosphorus
concentrations would increase at this depth within the three years of ef-
fluent additions. Retention of phosphorus, based on the mass balance for
39
-------
20.
15-
\
o>
E
o:
LJ
5_
• NO CUT
• ONE CUT
TWO CUTS
o EFFLUENT
1
5 20
25
1976
1 1
30 35
1
40
t—
15
«^~i
20
w^
25
WEEKS
1
30
1977
i
35
40
Figure 5-3: Weekly average mineral N concentrations in applied effluent and in soil-
water from the 15 cm depth of the 5 cm/week irrigation rate on the oldfield
wastewater irrigation site for various cutting treatments.
-------
• NO CUT
• ONE CUT
TWO CUT
o EFFLUENT
15
20
25 30
1976
40 15
WEEKS
Figure 5-4:
Weekly average mineral N concentrations in applied effluent and in soil-water
from the 15 cm depth of the 10 cm/week irrigation rate on the oldfield waste-
water irrigation site for various cutting treatments.
-------
NJ
• NO CUT
• ONE CUT
A TWO CUTS
o EFFLUENT
15
20
25 30
1976
1977
Figure 5-5: Weekly average mineral N concentrations in applied effluent and in soil-water
from the 120 cm depth of the 5 cm/week irrigation rate on the oldfield waste-
water irrigation site for various cutting treatments.
-------
MINERAL N (mg/liter)
H-
us
Ul
i
s; H, s:
fu i-i n>
rt o fD
fo a ?r
H h-»
rt *<
H- D4
t-i n> cu
n <
H- h-' fD
OQ N3 i-l
(BOW
rt OQ
H- O fD
§ s a
CL H-
cn fD 3
H- T3 (D
rt rt n
Mi O
O Mi 25
M
rt 0
< 3" O
Cu fD 3
H O
H- M fD
O 3
O
C
CO O
O
C
rt
rt
H-
3
OQ
rt
H-
O
H-
3
rt H
hi H- Cu
fD OQ T)
Cu Cu TJ
H- H-
fD
fD O
3 3
ft
CO l-i (D
• Cu Mi
rt Mi
fD I-1
O fD
3 3
rt
rt
£f cu
fD 3
O
M H-
Mi
H- CO
fD O
t-1 H-
Cu M
Cu Cu
CO rt
rt fD
fD i-i
ro _
01
CD
01
m
m
^
C/)
0«
I
ro
o
• m
O Z
Z O
m
o
C
01
ro _
01
-------
TABLE 5-7. MEAN ANNUAL ORGANIC PLUS AMMONIA NITROGEN CONCENTRATION IN
SOIL-WATER SAMPLES TAKEN FROM THE TOPSOIL AND FROM BELOW THE
ROOT ZONE OF THE OLDFIELD WASTEWATER IRRIGATION SITE, 1976
(VALUES IN mg N/£ + one std. dev.)
Irrigation Rate
0.0 cm/week
5.0 cm/week
10.0 cm/week
Vegetation
Management
No Cutting
One Cutting
Two Cuttings
No Cutting
One Cutting
Two Cuttings
No Cutting
One Cutting
Two Cuttings
15 cm Depth
*
*
*
1.51 4- 0.49
1.91 + 1.14
1.57 + 0.57
1.58 + 1.30
1.71 + 0.70
1.68 + 1.05
120 cm Depth
1.24 + 0.74
*
1.36 + 0.66
0.87 + 0.77
1.16 + 1.11
1.05 + 1.25
1.02 + 0.82
0.99 + 0.86
0.85 + 0.63
Insufficient number of samples to compute an average.
TABLE 5-8. MEAN ANNUAL ORTHOPHOSPHATE CONCENTRATION IN SOIL-WATER SAMPLES
TAKEN FROM THE TOPSOIL AND FROM BELOW THE ROOT ZONE OF THE OLD-
FIELD IRRIGATION SITE, 1976 (VALUES IN mg P/£ + one std. dev.)
Irrigation Rate
0.0 cm/week
5.0 cm/week
10 cm/week
Vegetation
Management
No Cutting
One Cutting
Two Cuttings
No Cutting
One Cutting
Two Cuttings
No Cutting
One Cutting
Two Cuttings
15 cm Depth
.150
.100
.240
.072
.128
.048
.282
.238
.088
+ .130
+ .110
+ .280
+ .109
+ .166
+ .102
+ .635
+ .402
+ .083
120 cm
.020 +
A
.022 +
.032 +
.036 +
.015 +
.023 +
.028 +
.021 +
Depth
.010
.008
.079
.110
.017
.031
.042
.029
Insufficient samples to establish an annual mean.
44
-------
1976, was very high (TABLE 5-9). While the soil-plant system effectively
immobilized added phosphorus, the one and two harvest managements removed
significant portions of the added P. This removal of P in harvest should
significantly extend the sorption capacity of the system resulting in pro-
longed usefulness of the site. With continued additions and crop removals
at the 1976 rates, accumulations of P on the site would occur at a rate
three and one-half times faster for the no harvest treatment than for the
two harvest treatment. Thus, the principle role of the harvest with re-
spect to P was to extend the life of the land treatment system for P re-
moval .
TABLE 5-9. PHOSPHORUS MASS BALANCE FOR 1976 FOR THE VARIOUS TREATMENTS
OF THE OLDFIELD SITE (VALUES IN kg P/ha)
Irrigation
Rate
0 cm/week
5 cm/week
10 cm/week
Management
No Cut
One Cut
Two Cuts
No Cut
One Cut
Two Cuts
No Cut
One Cut
Two Cuts
Effluent
Input
0.0
0.0
0.0
33.3
33.3
33.3
65.8
65.8
65.8
Crop
Removal
0.0
9.5
15.6
0.0
14.4
24.2
0.0
19.2
26.9
Recharge
0.01
0.01
0.01
0.40
0.45
0.19
0.55
0.67
0.51
Retained
0.0
-9.5
-15.6
32.9
18.5
8.9
65.3
45.9
38.4
Soil Samples
Soil samples were taken in the vicinity of the tube lysimeter sites
in spring of 1976 and fall of 1976 and were analyzed for major nutrients
and salts (TABLES 5-10 to 5-16). The relatively minor changes expected
were largely masked by the large amounts of these elements already in the
soil and by the inherent variability of the soil. The increases in ex-
changeable sodium and extractable chloride were the only observable changes
associated with the effluent treatments. Neither presented a water quality
or soil structural problem at observed levels (TABLES 5-10 to 5-16).
45
-------
TABLE 5-10. BRAY EXTRACTABLE PHOSPHORUS ANALYSES OF SOILS FOR THE OLDFIELD
WASTEWATER IRRIGATION STUDY (VALUES IN yg/g DRY SOIL)
0 cm/week
Depth (cm)
1975
1976
5 cm/week
1975
1976
10 cm/week
1975
1976
NO CUTTING MANAGEMENT
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
26.5
10.9
4.0
4.7
4.8
2.8
2.7
2.5
7.3
43.4
13.1
4.1
3.8
3.5
3.7
1.9
2.4
9.5
41.8
11.9
14.4
8.6
5.3
9.5
12.3
10.2
14.2
25.6
10.6
5.5
3.7
2.5
1.6
1.8
2.8
6.8
37.7
18.8
5.4
4.8
4.9
3.3
1.8
1.2
9.7
25.1
12.0
6.0
7.1
3.3
4.0
4.8
5.8
8.5
12.5
4.9
3.6
3.4
1.6
1.3
2.7
1.0
3.9
ONE CUTTING
58.9
16.5
12.8
20.7
10.9
18.7
7.9
6.6
19.1
TWO CUTTING
22.2
16.7
4.5
2.3
2.6
1.0
1.6
1.8
6.6
17.6
4.4
2.0
2.3
2.5
1.9
1.8
1.1
4.2
MANAGEMENT
26.6
8.4
8.4
10.1
5.5
5.7
4.1
4.5
9.2
MANAGEMENTS
16.1
7.2
2.4
2.6
2.2
2.6
3.0
2.3
4.8
24.8
9.7
3.2
3.7
2.8
3.1
1.9
1.8
6.3
34.0
15.3
11.8
9.1
4.7
7.3
7.7
7.2
12.1
24.3
6.9
17.2
1.8
2.8
3.9
3.4
1.9
7.7
25.1
9.8
3.9
4.4
3.3
2.8
1.9
2.0
6.7
33.9
11.7
10.6
12.8
12.0
10.0
4.7
9.2
13.1
29.9
10.8
4.4
4.3
3.4
2.4
2.3
2.0
7.4
46
-------
TABLE 5-11. EXCHANGEABLE POTASSIUM ANALYSES OF SOILS FOR THE OLDFIELD
WASTEWATER IRRIGATION STUDY (VALUES IN yg/g DRY SOIL)
0 cm/week
Depth (cm)
1975
1976
5 cm/week
1975
1976
10 cm/week
1975
1976
NO CUTTING MANAGEMENT
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
127.6
77.0
72.4
50.0
45.6
49.6
48.2
60.8
66.4
177.5
82.0
96.8
76.7
49.2
63.0
57.8
64.5
83.4
302.0
85.3
66.0
52.0
54.0
63.0
52.0
47.0
90.2
176.0
95.5
48.3
47.8
67.8
65.0
53.7
53.7
75.9
206.5
110.8
98.5
114.0
73.8
70.5
63.3
55.3
99.1
192.6
70.5
61.5
48.8
45.5
47.5
41.0
37.8
68.1
86.3
46.3
52.3
50.5
55.3
54.0
53.0
44.5
55.3
ONE CUTTING
146.0
72.8
49.3
54.5
42.7
37.2
45.5
44.8
61.6
TWO CUTTING
97.5
46.0
31.8
34.0
41.0
52.3
52.5
41.0
49.5
86.3
63.8
37.3
55.0
40.3
34.5
34.0
48.3
49.9
MANAGEMENT
164.3
69.0
53.0
48.3
44.4
40.3
40.5
41.5
62.6
MANAGEMENTS
68.3
51.8
60.0
50.0
59.7
54.5
41.3
49.3
54.3
96.8
42.8
54.3
47.8
37.8
40.8
33.5
30.8
48.0
131.6
50.2
46.4
36.6
33.5
33.6
50.2
37.0
52.4
91.5
45.3
38.5
56.3
48.3
56.3
56.5
80.5
59.1
84.8
62.3
65.5
52.8
42.0
56.3
88.7
29.8
60.3
116.6
53.5
67.0
56.5
35.3
, 40.5
-1 42.8
64.0
59.5
97.0
100.0
69.0
50.8
48.8
35.0
42.3
52.0
61.8
47
-------
TABLE 5-12. EXCHANGEABLE CALCIUM ANALYSES OF SOILS FOR THE OLDFIELD
WASTEWATER IRRIGATION STUDY (VALUES IN yg/g DRY SOIL)
0 cm/week
Depth (cm)
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
1975
840.2
704.8
800.2
743.6
808.6
1066.2
1231.4
1689.8
985.6
763.3
693.0
755.3
720.7
581.6
1020.0
2419.5
1556.3
1063.7
1138.0
890.7
759.7
775.0
780.3
880.0
1412.7
1688.3
1040.6
1976
836.3
777.3
652.0
736.3
966.0
1530.0
1367.7
2003.7
1108.6
798.2
819.3
635.0
1108.6
856.8
1676.0
2375.3
2318.3
1323.4
874.0
875.3
945.3
993.8
1517.8
2086.5
2037.3
2034.5
1420.5
5 cm/week
1975
NO CUTTING
1107.0
863.3
1225.3
1470.0
1660.3
2264.7
2092.7
2965.5
1706.1
ONE CUTTING
1036.5
1036.0
1383.8
1191.8
1229.7
1057.0
1925.5
1624.8
1310.6
TWO CUTTING
621.0
560.0
509.5
638.0
1025.0
1974.3
1870.5
1988.0
1148.3
1976
MANAGEMENT
1071.8
793.0
717.3
1020.5
1672.3
2291.3
2983.0
3087.8
1704.6
MANAGEMENT
1354.2
1261.3
1571.0
1567.8
1481.4
1544.5
1596.8
1625.0
1500.2
MANAGEMENTS
879.6
678.3
3491.3
747.8
1086.0
1163.3
1165.3
2414.3
1453.2
10 cm/week
1975
851.3
659.8
970.5
913.8
799.5
1350.0
2397.5
2654.3
1324.6
1121.8
893.0
1399.0
1274.8
814.3
1805.2
2641.6
1892.2
1480.2
821.0
753.3
649.3
1053.8
900.0
1127.5
1572.8
1909.5
1098.4
1976
1034.8
854.8
1267.0
1152.3
891.3
2020.8
2061.7
3972.3
1656.8
1346.5
1785.3
1233.8
1146.8
910.3
1839.0
2735.0
2248.3
1655.6
1075.2
864.3
1184.3
830.8
848.3
1057.3
1529.0
1680.0
1133.6
48
-------
TABLE 5-13. EXCHANGEABLE MAGNESIUM ANALYSES OF SOILS FOR THE OLDFIELD
WASTEWATER IRRIGATION STUDY (VALUES IN yg/g DRY SOIL)
0 cm/week
5 cm/week
10 cm/week
Depth (cm)
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
1975
134.6
104.0
138.6
121.4
146.0
204.8
221.0
285.6
169.5
103.3
102.0
120.3
95.3
97.8
235.8
266.8
317.8
167.4
176.7
126.3
146.3
134.3
153.3
190.3
233.3
176.0
167.1
1976
99.6
83.3
80.5
78.3
162.3
276.0
214.7
253.3
156.0
91.8
83.5
79.0
199.4
144.8
254.5
338.5
294.0
185.7
105.7
96.0
121.5
159.5
108.8
84.3
126.0
136.0
117.2
1975
NO CUTTING
172.0
145.3
203.7
231.5
289.0
298.3
288.3
227.3
231.9
ONE CUTTING
215.3
148.0
179.0
189.8
217.0
155.4
182.3
168.3
181.9
TWO CUTTING
134.5
69.5
83.5
124.0
220.8
297.0
329.0
214.5
184.1
1976
MANAGEMENT
155.7
105.5
103.3
177.0
200.0
195.5
160.8
171.3
158.6
MANAGEMENT
228.7
195.8
172.0
242.8
99.8
117.8
127.3
143.0
165.9
MANAGEMENTS
166.3
124.5
142.5
139.5
230.3
255.8
289.8
262.0
201.3
1975
158.0
137.8
220.0
200.8
181.5
175.8
159.5
160.0
174.2
181.8
115.2
146.2
132.0
117.8
116.8
142.0
130.0
135.2
156.3
96.5
101.8
162.3
175.0
249.8
262.0
319.5
190.4
1976
168.8
152.0
241.0
238.3
208.3
313.8
252.7
348.0
240.3
233.8
195.3
142.0
151.0
125.3
97.8
136.8
149.8
153.9
186.2
148.3
181.3
137.3
148.3
121.3
171.5
189.8
160.5
49
-------
TABLE 5-14. EXCHANGEABLE SODIUM ANALYSES OF SOILS FOR THE OLDFIELD
WASTEWATER IRRIGATION STUDY (VALUES IN yg/g DRY SOIL)
Depth (cm)
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0
1975
32.0
33.0
32.4
33.8
36.2
45.0
44.0
48.4
38.1
31.5
32.3
25.8
26.3
30.0
39.0
53.3
47.5
35.7
30.3
34.3
28.0
32.7
34.0
35.3
35.3
72.0
37.8
cm/week
1976
27.7
28.0
43.8
29.3
27.0
36.5
38.3
43.0
34.2
25.0
28.5
31.8
28.0
29.0
33.0
35.5
41.7
31.6
26.8
25.8
31.3
28.5
32.5
39.3
31.8
37.0
31.6
5 cm/week
1975 1976
NO CUTTING MANAGEMENT
44.7 81.1
72.7 92.8
80.3 80.5
88.5 115.5
94.0 87.3
67.7 69.8
52.3 66.3
56.8 62.3
69.6 81.9
ONE CUTTING MANAGEMENT
50.8 130.8
65.3 131.3
86.8 111.3
74.5 114.0
46.0 81.8
50.2 73.8
51.8 64.0
50.3 62.8
59.4 96.2
TWO CUTTING MANAGEMENTS
40.8 99.0
57.5 90.3
54.0 79.3
58.5 86.0
61.3 149.3
69.8 88.3
60.3 66.3
53.5 71.3
56.9 91.2
10
1975
52.0
69.8
83.8
55.3
48.5
56.5
54.0
66.5
60.8
53.6
63.6
73.8
55.4
52.0
51.4
47.6
54.2
56.5
44.3
64.3
57.3
76.5
67.5
68.0
58.3
76.5
64.1
cm/week
1976
90.3
109.0
118.3
95.0
85.8
107.3
96.7
81.0
97.9
119.0
120.0
114.8
101.0
78.5
88.8
78.5
89.3
98.7
94.9
99.3
89.3
89.5
92.0
76.8
89.5
92.0
90.4
50
-------
TABLE 5-15. POTASSIUM SULFATE EXTRACTABLE CHLORIDE ANALYSES OF SOILS
FOR THE OLDFIELD WASTEWATER IRRIGATION STUDY (VALUES IN
yg/g DRY SOIL)
0 cm/week
Depth (cm)
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
1975
5.1
10.4
4.6
4.6
6.0
7.9
8.0
6.8
6.7
11.9
6.6
14.4
7.7
5.9
6.1
8.7
6.9
8.5
11.0
6.7
3.8
4.6
5.0
6.5
6.5
6.8
6.4
1976
10.7
8.4
7.5
7.2
6.4
9.1
7.3
8.8
8.2
11.9
7.7
9.3
7.8
8.5
7.5
9.1
10.3
9.0
10.5
8.5
7.3
6.2
8.8
8.1
6.7
7.4
7.9
5 cm/week
1975
NO CUTTING
16.0
13.1
14.7
11.9
23.4
20.4
20.3
25.3
18.1
ONE CUTTING
15.9
9.5
13.8
12.9
16.4
11.9
17.2
14.6
14.0
TWO CUTTING
20.0
12.3
9.4
12.3
16.4
21.7
20.6
27.8
17.6
1976
MANAGEMENT
34.7
29.7
26.8
35.5
27.8
28.6
29.6
35.2
31.0
MANAGEMENT
41.6
31.6
34.6
34.1
32.3
29.2
26.7
23.5
31.7
MANAGEMENTS
39.8
24.0
25.2
26.6
27.5
25.5
31.0
29.2
28.6
10 cm/week
1975
19.8
13.3
12.5
10.6
10.4
13.7
21.1
24.6
15.8
14.5
10.7
11.0
11.6
11.3
14.1
18.3
14.6
13.3
15.8
10.5
10.0
10.0
14.6
17.9
21.2
24.9
15.6
1976
33.3
32.1
28.4
27.0
25.2
33.7
36.2
28.4
30.5
35.5
31.4
29.6
27.2
24.0
28.7
26.8
27.4
28.8
30.6
22.8
21.7
23.6
21.1
26.0
25.5
26.8
24.8
51
-------
TABLE 5-16. POTASSIUM SULFATE EXTRACTABLE NITRATE-NITROGEN ANALYSES
OF SOILS FOR THE OLDFIELD WASTEWATER IRRIGATION STUDY
(VALUES IN yg/g DRY SOIL)
Depth (cm)
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
Average
0
1975
4.5
5.1
1.1
0.9
1.0
1.8
1.8
1.7
2.2
5.8
3.1
2.4
0.8
1.6
0.7
1.5
1.1
2.1
7.8
4.2
1.6
4.2
2.9
1.7
1.3
2.3
3.2
cm/week
1976
1.5
1.1
0.9
0.8
0.6
0.9
0.7
1.0
0.9
1.8
1.0
1.0
0.9
1.0
0.8
1.1
1.1
1.1
1.9
1.4
1.1
0.7
0.8
0.9
0.8
0.8
1.0
5 cm/week
1975 1976
NO CUTTING MANAGEMENT
1.8 2.2
10.2 1.5
5.8 1.1
12.9 1.3
6.2 1.1
5.8 1.3
1.0 1.2
2.0 1.7
5.7 1.4
ONE CUTTING MANAGEMENT
11.7 3.6
6.3 2.1
2.9 1.9
2.8 1.4
1.4 1.2
1.8 0.9
1.9 1.1
1.0 0.9
3.7 1.6
TWO CUTTING MANAGEMENTS
14.2 1.7
2.1 1.1
2.2 1.0
1.9 1.1
1.5 1.2
1.3 1.1
1.2 1.3
16.1 1.4
5.1 1.2
10
1975
19.6
2.4
2.1
0.9
1.2
2.5
1.9
2.3
4.1
17.6
2.2
3.6
1.6
1.5
3.0
1.4
2.1
4.1
2.3
1.6
1.2
1.1
1.8
1.7
2.0
1.8
1.7
cm/week
1976
2.5
2.0
1.7
1.6
1.5
2.3
2.5
2.1
2.0
4.0
2.6
2.2
1.8
1.8
1.4
1.3
1.2
2.0
4.5
3.0
2.4
2.2
1.5
2.0
1.8
2.0
2.4
52
-------
Runoff
Runoff from a tile drain that drains the 3.6 ha oldfield irrigation
site plus 7.7 ha area of adjacent unirrigated oldfields was monitored using
an ISCO sequential sampler in 1976 and 1977 (TABLES 5-17 to 5-21). Moni-
toring of the tile upstream of the spray irrigation site indicated that
there was very little runoff from the 7.7 ha unirrigated area and that
this runoff occurred only during Spring runoff or during one or two large
rainfall events during other seasons. Thus, the majority of the runoff
can be assigned to the 3.6 ha irrigation area. If the runoff is assigned
to the entire 11.32 ha oldfield drainage area, the unit area loads result-
ing from wastewater irrigation are likely to be low (TABLES 5-17 to 5-21).
If all the runoff were assigned to just the 3.6 ha spray irrigation area,
the unit area loads estimate would be slightly high, especially during
Spring runoff, but would be very close to actual runoff from this area.
The average wastewater application over the area was 7.5 cm/week with half
the area receiving 5 cm/week and the other half receiving 10 cm/week. If
all runoff were assigned to the 3.6 ha spray irrigation area, maximum unit
area load losses would be 2.96 kg/ha total P, 9.80 kg/ha N03-N, 0.43 kg/ha
NH4-N, 0.18 kg/ha N02-N, 7.78 kg/ha kjeldahl N, and 207.55 kg/ha chloride.
The maximum mineral or inorganic N runoff losses would be 10.41 kg N/ha
and the maximum organic N losses would be 7.35 kg N/ha. All of the mass
balances for the spray irrigation plots (TABLES 5-5, 5-6, and 5-9) were
calculated by assuming no runoff. The amount retained on site could be
in error by as much as twice the above if all runoff originated from the
10 cm/week, 1.8 ha area (TABLES 5-6 and 5-9). In any event, such losses
are only 6-7% of the total amount of each constituent applied in waste-
water and would not change the retention figures in the mass balances to
any significant degree. Thus, the mass balances are substantially correct
as calculated in TABLES 5-4, 5-5, 5-6, and 5-9.
Even though only 7% or less of the constituents applied in wastewater
ranoff, peak concentrations were still quite high and sometimes exceeded
the 1.0 mg V/i Michigan wastewater standard (Figure 5-7) and approached
the 10 mg NO--N/& EPA interim drinking water standard (Figure 5-8). The
likely explanation for these high peak concentrations is that sand lenses
53
-------
TABLE 5-17.
STREAM EXPORT OF MOLYBDATE REACTIVE PHOSPHORUS AND TOTAL PHOSPHORUS FROM THE 11 32 ha
OLDFIELD IRRIGATION SITE*
— —
Season
Summer, 1976
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Spring Post Runoff '77
Summer, 1977
Total 76-77 Water Year
% of Total
Summer, 1976
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Spring Post Runoff '77
Summer, 1977
Total 76-77 Water Year
% of Total
*
Rising
Hydrograph (kg)
M 0 L
0.096 + 0.001
0
0
0.191 + 0.000
ND**
ND
0.111 + 0.001
0
0
0.580 + 0.000
0.089 + 0.001
1.193 + 0.019
1.862 + 0.019
17.49
PT OT.TQ
Descending
Hydrograph (kg)
Y B D A T E
0.719 + 0.029
0
0
2.991 + 0.069
ND
ND
____
_____
TOTAL
0.797 + 0.027
0
0
7.261 + 0.446
0.191 + 0.006
1.268 + 0.069
8.720 + 0.451
81.90
Non-Event
Flows (kg)
R E A C T I V
0.026 + 0.014
0
0
0.004 + 0.000
ND
ND
P H 0 S P H 0
0.035 + 0.016
0
0
0.007 + 0.000
0.020 + 0.000
0.038 + 0.000
0.065 + 0.000
0.61
Export Total
(kg)
E P H 0 S P H
0.841 + 0.032
0
0
3.186 + 0.069
ND
ND
R U S
0.943 + 0.031
0
0
7.848 + 0.446
0.300 + 0.006
2.499 + 0.072
10.647 + 0.451
% of
Total
0 R U S
o
o
ND
ND
_
0
o
73.71
2.82
23.47
Unit
Area
Loads
(kg/ha)
0.074
o
o
0.281
ND
ND
0.083
o
o
0.693
0.026
0.221
0.940
The unit area loads were calculated for the 11.32 ha total area drained; the irrigation area was
only 3.6 ha; the average irrigation rate was 7.5 cm/week for the entire site.
ND indicates no data.
-------
TABLE 5-18.
STREAM EXPORT OF NITRATE AND AMMONIA NITROGEN FROM THE 11.32 ha OLDFIELD IRRIGATION
SITE*
Ul
Season
Summer, 1976
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Spring Post Runoff '77
Summer, 1977
Total 76-77 Water Year
% of Total
Summer, 1976
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Spring Post Runoff '77
Summer, 1977
Total 76-77 Water Year
% of Total
T71
— — Ci
Rising
Hydrograph
(kg)
0.
7.
0.
3.
11.
0.
0.
0.
0.
0.
385 + 0.
0
0
815 + 0.
916 + 0.
107 + 0.
838 + 0.
33.54
010 + 0.
0
0
046 + 0.
040 + 0.
825 + 0.
911 + 0.
59.00
^ENT
003
000
004
030
030
0001
000
001
001
001
T?T niJQ — — — —
Descending
Hydrograph
(kg)
N I T R A
1.785 + 0.026
0
0
16.973 + 0.273
1.285 + 0.014
4.953 + 0.128
23.211 + 0.302
65.77
A M M 0 N
0.090 + .002
0
0
0.528 + .008
0.030 + .0004
0.069 + .001
0.627 + .008
40.61
Non-Event
Flows (kg)
TE-NITRO
0.
0.
0.
0.
0.
I
0.
0.
0.
0.
0.
260 + 0.
0
0
051 + 0.
003 + 0.
188 + 0.
242 + 0.
0.69
A - N I
016 + 0.
0
0
002 + 0.
001 + 0.
003 + 0.
,006 + 0.
0.39
034
000
000
000
000
T R 0
004
000
00001
000
,00001
Export Total
(kg)
GEN
2.430 +
0
0
24.839 +
2.204 +
8.248 +
35.291 +
GEN
0.116 +
0
0
0.576 +
0.071 +
0.897 +
1.544 ±
0.043
0.273
0.015
0.131
0.303
.005
.008
.001
.001
.008
% of
Total
0
0
70.38
6.25
23.37
0
0
37.31
4.60
58.10
Unit
Area
Loads
(kg/ha)
0.215
0
0
2.194
0.195
0.728
3.118
0
0
0.051
0.006
0.079
0.136
The unit area loads were calculated for the 11.32 ha total area drained; the irrigation area was
only 3.6 ha; the average irrigation rate was 7.5 cm/week for the entire site.
-------
TABLE 5-19.
STREAM EXPORT OF NITRITE AND KJELDAHL NITROGEN FROM THE 11.32 ha OLDFIELD IRRIGATION
SITE*
Ui
Season
Summer, 1976
Fall, 1976
Winter 1976-77
Spring Runoff 1977
Spring Post Runoff '77
Summer, 1977
Total 76-77 Water Year
% of Total
Summer, 1976
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Spring Post Runoff '77
Summer, 1977
Total 76-77 Water year
% of Total
Rising
Hydrograpl
(kg)
0
0
0
0
0
0
EVENT FLOWS •
Descend:
i Hydrogr;
(kg)
.071 + 0.001
0
0
.057 + 0.000
.006 + 0.0001
.098 + 0.001
.161 + 0.001
24.58
.335 + 0.
0
0
3.241 + 0.
0.447 + 0.
2.094 + 0.
5.782 + 0.
20.64
002
000
001
017
017
0
0
0
0
0
1
N I
.349 +
0
0
ing
aph
T R I
.016
.383 + .007
.017 + .001
.092 + .003
.492 + .008
75.11
K J E
.568 +
0
0
L D A
.028
17.681 + .463
1.584 + .031
2.792 + .092
22.057 + .473
78.74
Non-Event
Flows (kg)
Total Exports
(kg)
% of
Total
Unit
Area
Loads
(kg/ha)
TE-NITROGEN
0.024 + 0.026
0
0
0.0007 + 0.000
0.0002 + 0.000
0.001 + 0.000
0.002 + 0.000
0.31
0.444 +
n
o
.031
0.441 + .007
0.023 + .001
0.191 + .004
0.655 + .008
100.00
— ___
67.33
3.51
29.16
0.039
0.039
0.002
0.017
0.058
HL-NITROGEN
0.183 + 0.035
0
0
0.038 + 0.000
0.010 + 0.000
0.126 + 0.000
0.174 + 0.000
0.62
2.086 +
o
o
20.960 +
2.041 +
5.012 +
28.013 +
.045
.463
.031
.094
.474
— _
n
n
74.82
7.29
17.89
0.184
fj
1.852
0.180
0.443
2.475
— .
The Unit Area Loads were calculated for the 11.32 ha total area drained; the irrigation area was
only j.6 ha; the average irrigation rate was 7.5 cm/week.
-------
TABLE 5-20.
STREAM EXPORT OF CHLORIDE AND SUSPENDED SOLIDS FROM THE 11.32 ha OLDFIELD IRRIGATION SITE*
— . —
Season
Summer, 1976
Fall, 1976
Winter 1976-77
Spring Runoff 1977
Spring Post Runoff '77
Summer, 1977
Total 76-77 Water Year
% of Total
Summer, 1976
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Spring Post Runoff '77
Summer, 1977
Total 76-77 Water Year
% of Total
Trwirwn
Rising
Hydrograph
(kg)
37.90 + 0.26
0
0
151.22 + 0.00
16.19 + 0.19
96.89 + 0.73
264.30 + 0.75
35.37
2.96 + 0.02
0
0
ND**
ND
ND
— — —
1 TTT OWS
Descending
Hydrograph
(kg)
C H
153.68 + 0.10
0
0
311.06 + 2.34
57.01 + 0.22
106.43 + 0.12
474.50 + 2.35
63.51
S U S P E N
20.89 + 1.48
0
0
477.30 + 35.46
ND
ND
___
Non-Event
Flows (kg)
L 0 R I D E
22.33 + 0.21
0
0
1.29 + 0.00
0.77 + 0.00
6.31 + 0.00
8.37 + 0.00
1.12
D E D SOL
1.91 ± 1.03
0
0
ND
ND
ND
Total Exports
(kg)
213.91 + 0.35
0
463.57 + 2.34
73.97 + 0.29
209.63 + 0.74
747.17 + 2.47
IDS
25.76 + 1.80
0
ND
ND
ND
% Total
0
62.04
9.90
28.06
0
ND
ND
ND
Unit
Load
(kg/ha)
18.90
0
Q
40.95
6.53
18.52
66.00
2.28
0
ND
ND
ND
**
The Unit Area Loads were calculated for the 11.32 ha total area drained; the irrigation area was
only 3.6 ha; the average irrigation rate was 7.5 cm/week.
ND indicates no data.
-------
TABLE 5-21. STREAM EXPORT OF SODIUM AND CALCIUM FROM THE 11.32 ha OLDFIELD IRRIGATION
SITE*
Season
Summer, 1976
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
EVENT FLOWS
Rising Descending
Hydrograph Hydrograph
(kg) (kg)
SODIUM
32.89+0.17 99.98+ 1.42 13.26+0.79
0 0 o
0 0 o
135.01+0.00 259.50+18.92 0.29+0.00
Unit
Non-Event Total Exports % of Area
Flows (kg) (kg) Total// Load
(kg/ha)
146.13 + 1.63 12.91
0
0
0
0
394.80 + 18.92
0
0
34.88
Ul
oo
Summer, 1976
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
CALCIUM
48.28+0.36 91.60+0.10 16.22+0.89 156.10+0.97 ____ 13.79
0 0 0 0 0 o'
371.29+0.00 314.48+0.81 2.70+0.00 688. 47°+ 0.81 ---
60.82
was onlv f fiV^ ™™ Calculated for the 1]-32 ha total area drained; the irrigation area
was only 3.6 ha; the average irrigation rate was 7.5 cm/week.
No complete water year data available.
-------
and eroded areas allowed direct connection to the tile drain during the
actual spray irrigation. Some eroded areas resulting in cave-ins and direct
holes leading to the tile were found and filled in but others could have
been missed. Similar problems for tile drainage from a wastewater irriga-
tion study of corn at a nearby area have been reported and attributed to
0 /
direct connection to the tiles via sand lenses. It would appear that
oldfield areas with good infiltration characteristics should not be tiled
and that an effort to control runoff would increase the renovation effi-
ciency of such sites by utilizing the renovation potential of the soil-
plant system to the greatest extent.
It is also interesting to note that 99% or more of every constituent
measured in runoff was exported during runoff events with low flow contri-
buting less than 1% to the total amount exported. The importance of run-
off events in losses is likely the result of the high peak concentrations
of each constituent as discussed above (Figures 5-7 and 5-8), the low
concentrations in low flow, and the fact that almost all discharge during
the summer and fall is wastewater generated with the tile drain drying up
between each wastewater application.
CONCLUSIONS AND RECOMMENDATIONS
The oldfield proved to be very effective in the treatment of municipal
wastewater. Nitrate concentrations in the water leaching past the 120 cm
depth stayed within recommended drinking water quality limits throughout
the irrigation season. Phosphorus concentrations in soil-water remained
at background levels during the study period.
While the unharvested vegetation effectively prevented nitrate move-
ment with recharge waters, harvest of the vegetation provided assurance
that N would be removed from the site and therefore could not build up to
leach out at some later time. The harvest also lengthened the effective
life of the soil for retention of P by removing a substantial portion of
the added P.
Tile drains for such oldfield systems should be avoided if possible
since peak concentrations of N and P sometimes exceeded drinking water
and/or wastewater standards. High peak concentrations represented only a
59
-------
q
CD
q
in
mg/liter N
q o
ro
1 1 T
q oq
cfl IH
o o
co a
•H 3
t> H
CO T3
3 CU
CO 4-1
>-l Cfl
cu v-i
> 0)
C CU
O 60
•H
4-1 C
Cfl O
C CO
CU 60
O -H
PI fc
O ^
CJ -H
m
cu
3
60
60
-------
.1.0
200 1400 1600 1800 2000 2200 240O 0200 0400 0600 0800 1000 1200 1400
7-12 7-13
Figure 5-8. Concentration versus discharge for total P, total N, and N03-N for a wastewater
irrigation generated runoff event (July 12, 1976).
-------
small fraction of total applied wastewater but could still lead to local
eutrophication problems if not controlled.
Use of oldfields for wastewater treatment has the advantage that pro-
ductive agricultural lands do not need to be purchased or leased for the
treatment of wastewater. Consideration should be given to use of harvest
material for green manure, compost or animal feed when the oldfields are
harvested.
The grass cutting management demonstrated that simpler management
schemes are available which will effectively prevent nitrate leaching.
Because the life of the land application system could be lengthened by
harvest, this management would be preferable where maximum design life is
desired. However, when harvest of the grass is unfeasible, frequent mowing
can effectively control nitrate leaching at least for short duration sys-
tems. Without harvest or cutting, the grass was still effective, but the
vegetation would probably revert to an oldfield flora if the no cutting
management option were adopted.
62
-------
REFERENCES
1. Seitz, W.D. and E.R. Swanson. Economic Aspects of the Application
of Municipal Wastes to Agricultural Land. In: Recycling Municipal
Sludges and Effluents on Land, Proceedings of the Nat. Asso. of
State University and Land Grant Colleges, D.R. Wright, Chairman.
Library of Congress Catalog Number 73-88570, Washington, D.C., 1973.
pp. 175-182.
2. Evans, J.O. Research Needs - Land Disposal of Municipal Sewage
Wastes. In: Recycling Treated Municipal Wastewater and Sludge Through
Forest and Cropland, W.E. Sopper and L.T. Kardos, eds. The Pennsyl-
vania State University Press, University Park, Pennsylvania, 1973.
pp. 455-562.
3. Melsted, S.W. Soil-Plant Relationships (Some Practical Considerations
in Waste Management). In: Recycling Municipal Sludges and Effluents
on Land, Proceedings of the Nat. Asso. of State Universities and Land
Grant Colleges, D.R. Wright, Chairman. Library of Congress Catalog
Number 73-88570, 1973. pp. 121-128.
4. Hook, J.E. and L.T. Kardos. Nitrate Leaching During Long-Term
Spray Irrigation of Secondary Sewage Effluent on Woodland Sites.
J. Env. Qual., 7:30-34, 1978.
5. Sopper, W.E. and S. Kerr. Effects of Recycling Treated Municipal
Wastewater in Eastern Hardwood Forests. In: Municipal Wastewater
and Sludge Recycling on Forest Land and Disturbed Land. W.E. Sopper,
ed. Pennsylvania State University Press, University Park, Pennsyl-
vania, 1978. (In press.)
6. Sopper, W.E. and L.T. Kardos. Vegetation Responses to Irrigation with
Treated Municipal Wastewater. In: Recycling Treated Municipal
Wastewater and Sludges Through Forest and Cropland, W.E. Sopper and
L.T. Kardos, eds. Pennsylvania State University Press, University
Park, Pennsylvania, 1973. pp. 271-294.
7. Wells, D.M., R.M. Sweazy, F. Gray, C.C. Jaynes, and W.F. Bennett.
Effluent Reuse in Lubbock. In: Land as a Waste Management Alterna-
tive, R.C. Loehr, ed. Ann Arbor Science Pub., Inc., Ann Arbor,
Michigan, 1977. pp. 451-466.
8. Hook, J.E. and L.T. Kardos. Nitrate Relationships in the Penn State
"Living Filter" System. In: Land as a Waste Management Alternative,
R.C. Loehr, ed. Ann Arbor Science Pub., Inc., Ann Arbor, Michigan,
1977. pp. 181-198.
63
-------
9. Ketchum, B.H. and R.F. Vaccaro. Removal of Nutrients and Trace
Metals by Spray Irrigation and in a Sand Filter Bed. In: Land as a
Waste Management Alternative, R.C. Loehr, ed. Ann Arbor Science Pub
Inc., Ann Arbor, Michigan, 1977. pp. 413-434.
10. Clapp, C.E., D.R. Linden, W.E. Larson, and J.R. Nyland. Nitrogen
Removal from Wastewater Effluent by a Crop Irrigation System. In-
Land as a Waste Management Alternative, R.C. Loehr, ed. Ann Arbor
Science Pub., Inc., Ann Arbor, Mihcigan, 1977. pp. 139-150.
11. Day, A.D. and T.C. Tucker. Hay Production of Small Grains Utilizing
City Sewage Effluent. Agron. J., 52:238-239, 1960.
12. Thornthwaite, D.W. and J.R. Mather. Instructions and Tables for
Computing Potential Evapotranspiration and the Water Balance.
Pubs, in Climatology, Vol. 10. Laboratory of Climatology, Drexel
Institute of Technology, Centerton, New Jersey, 1967. pp. 185-311.
13. Milham, P.J., A.S. Awad, R.E. Paull, and J.H Bull. Analysis of
Plants, Soils and Waters for Nitrate by Using an Ion-Selective
Electrode. Analyst 95:751-753, 1970.
14. Orion Research, Inc. Instruction Manual. Ammonia Electrode. Orion
Research, Inc., Cambridge, Massachusetts, 1971. 24 pp.
15. Bremner, J.M. and D.R. Keeney. Steam-Distillation Methods for Deter-
mination of Ammonium, Nitrate, and Nitrite. Anal. Chim Acta
32:485-495, 1965.
16. Nelson, D.W. and L.E. Sommers. Determination of Total Nitrogen in
Natural Waters. J. Env. Qual. , 4:465-468, 1975.
17. Nelson, D.W. and L.E. Sommers. Determination of Total Nitrogen in
Plant Material. Agron. J., 65:109-112, 1973.
18. American Public Health Association. Standard Methods for the Exami-
nation of Water and Wastewater. 13th edition. Washington, D.C.,
1971. 874 pp.
19. Bremner, J.M. Inorganic Forms of Nitrogen. In: Methods of Soil
Analysis. C.A. Black, ed. Agronomy 9:1179-1237. Am. Soc. Agron.,
Madison, Wisconsin, 1965.
20. Pratt, P.P. Potassium. In: Methods of Soil Analysis. C.A. Black
ed. Agronomy 9:1022-1030. Am. Soc. Agron., Madison, Wisconsin, 1965.
21. Jackson, M.L. Soil Chemistry Analysis. Prentice-Hall, Inc.,
Englewood Cliffs, New Jersey, 1958.
22. Murphy, J. and J.P. Riley. A Modification Single Solution Method for
the Determination of Phosphate in Natural Waters. Anal. Chim. Acta.,
£• I • j _i_ ~~ j o j J.y o^ •
64
-------
23. Broadbent, F.E. Factors Affecting Nitrification-Denitrification in
Soils. In: Recycling Treated Municipal Wastewater and Sludge
Through Forest and Cropland. W.E. Sopper and L.T. Kardos, eds.
The Pennsylvania State University Press, University Park, Pennsyl-
vania, 1973. pp. 232-244.
24. Karlen, D.L., M.L. Vitosh, and R.J. Kunze. Irrigation of Corn with
Simulated Municipal Sewage Effluent. J. Env. Qual., 5(3):269-273,
1976.
65
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SECTION 6
LAND APPLICATION TO CROPLANDS
James E. Hook and M.B. Tesar
INTRODUCTION
In implementing Public Law 92-500, municipal planners must evaluate
land treatment as an alternative for conventional wastewater treatment.
To make a proper evaluation, planners must be able to design a land
treatment system which has a predictable performance. When considering
a conventional treatment plant, designers have a choice of components —
each component having a generally predictable performance for a given
range of conditions. However, when considering land treatment, designers
have few choices with known effectiveness for the one, perhaps most criti-
cal component, the vegetation. To aid them in planning and designing, we
need to recommend crops which will have predictable effectiveness for reno-
vation of wastewater, particularly with respect to nitrogen. We need to
offer alternatives in crops and in management which improve effectiveness
while minimizing operational problems.
Wastewater treatment systems which use rates of water much in excess
of crop needs are common. These systems do not necessarily behave as
conventionally fertilized and irrigated cropland, particularly with respect
to nitrogen nutrition and leaching. Field studies evaluating performance
of several crops irrigated with municipal effluent have been or are being
conducted at several locations.1'8 With most, at least one of the objec-
tives has been to develop crop or other vegetation management systems which
will effectively remove nitrogen from the wastewater thereby preventing
groundwater or surface water contamination.
A study to assess the effectiveness of a variety of forage crop
species and managements for removal of nitrogen and other major nutrients
from wastewater was initiated as part of the IJC studies as an adjunct to
66
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crop response studies already underway on the Water Quality Management
Facility (WQMF) at Michigan State University. The purpose of this study
was to compare the effectiveness of several important agronomic crops in
the land treatment of municipal wastewaters. More specifically, it sought
to determine how growth and harvest of the crops affects when and how much
of wastewater constituents may leach to and contaminate groundwater.
Furthermore, this leachate quality should serve as an indication of runoff
quality from such land application areas where runoff occurs.
MATERIALS AND METHODS
Site Description
The experimental site was located in the northwest corner of the Water
Quality Management Facility (WQMF) wastewater irrigation site on the campus
of the Michigan State University. The soil was classified by high inten-
sity mapping as a Miami loam. This soil is a member of the fine-loamy,
mixed mesic family of Typic Hapludalfs developed on silt to loam till.
Chemical analyses of major horizons are provided in TABLE 6-1. The soil
was naturally well drained, but tensiometer measurements made during the
middle of the summer irrigation season just prior to one of the irrigation
TABLE 6-1. MEAN CONCENTRATIONS OF BRAY EXTRACTABLE P, EXCHANGEABLE CATIONS
AND pH OF ALL TREATMENT PLOTS AT THE START OF THE 1976 to 1977
STUDY PERIOD (VALUES IN pg/g DRY SOIL)
Depth (cm)
15
30
60
90
120
150
180
210
240
270
300
Bray P
12.5
4.0
2.9
3.0
2.1
1.0
0.8
1.0
1.6
1.4
1.2
K
43
36
51
55
47
40
35
36
31
30
24
Ca
1406
903
993
1295
2083
2779
2902
2810
2513
2246
1824
Mg
88
86
154
255
261
220
181
177
149
138
100
Na
94
93
91
94
90
88
83
80
82
84
78
PH
7.6
7.3
6.7
6.8
7.5
7.9
8.2
8.2
8.2
8.2
8.4
67
-------
periods indicated the formation of a perched water table in the range of
the 1.0 to 1.8 m depth under the high irrigation treatment. This perched
water table did not subside completely between the three weekly applications,
Plot Design and Treatments
A split plot design was used to compare effects of weekly irrigation
levels, crop types and species or varieties. The split of crop type into
species or varieties was not of direct concern for this study. The weekly
irrigation rates were 2.5, 5.0 and 7.5 cm/week. The crop types were peren-
nial grasses, perennial legumes, annuals and no vegetation. Each plot
containing the crop type was 9.1 x 18.2 m and was replicated three times
within each irrigation rate. Because of physical limitations irrigation
rates were not replicated.
The perennial grasses and legumes were established in August 1973.
The grasses were Phalaris arundinacea, L., Festuca arundinacea, Schreb.,
Dactylis glomerata, L., Alopecurus arundinacea, Poir, Poa pratensis. Leyss,
Phleum pratense, Leyss, and two varieties of Bromus inermis, Leyss. The
legume plots contained two varieties of Lotus corniculatus, L. and six of
Medicago sativa, L. The annuals, two varieties of Zea mays, L., Sorghum
sudanense, P. Stapf, and Sorghum bicolor, L. Moench, were planted no-till
into a fall sown crop of rye which had been killed by herbicide treatment
with "Roundup" just prior to planting. The no vegetation plots were
sprayed with "Roundup" as needed to eliminate all plant growth. A small
amount of fertilizer was used on all cropped plots. The annuals received
22.4, 9.7, 111.5 kg/ha of N, P, and K, respectively, in a band 50 mm to
the side and 50 mm below the row at planting. The grasses and legumes
received the same amounts as the annuals by broadcast application following
either the first or second harvest each year.
Municipal sewage effluent was taken from a pipeline from the East
Lansing Sewage Treatment Plant. This water was of poor tertiary quality
in 1974 and 1975 and was of secondary quality during the 1976-77 study
period reported here. During periods of peak pumping, water was back-
siphoned from the first of four effluent receiving lakes; this back-
siphoning generally lowered the total N concentrations of effluent sprayed
68
-------
onto the site because of N stripping processes occuring in the lake. All
effluent was chlorinated just prior to spraying.
Effluent was applied at a rate of 3.81 cm/hour in 1974 and 1975 and
at 0.85 cm/hour in 1976 and 1977 for the time period necessary for a daily
application of 2.5 cm. The three weekly rates of 2.5, 5.0 and 7.5 cm were
accomplished by irrigating 1, 2 and 3 days per week, respectively. The
irrigation season was usually from mid-spring to mid-fall.
Sampling and Analyses
Wastewater was sampled from each application with acid washed poly-
ethylene funnel collectors placed one meter above the ground. Soil-water
was sampled using porous cup vacuum type samplers evacuated to 0.8 atmos-
pheres immediately before one weekly irrigation and sampled 48 hours later.
The porous cups were placed at depths of 15 and 150 cm below the surface
and were connected by small diameter acrylic tubing to a sample vacuum
chamber located on the surface about 3 m from the cup location. This
separation of cup and sample chamber eliminated traffic in the vegetation
around the sampler, prevented short circuiting of effluent from ground
surface to the cups and facilitated harvest.
Though the crop plots contained more than one species or variety,
the sampling devices were placed in the same species in each replicate.
Thus, samplers in the annual plots were always in the center of one of the
3.0 x 9.1 m corn sub-plots; in the legume plots, they were always in the
alfalfa sub-plot; and in the grass plots, they were always in either the
reed canary grass sub-plot, the tall fescue sub-plot, or in the orchard
grass sub-plot. These three species had similar yields. These sub-plots
were too small to be certain that mixing of leachate from neighboring plots
did not affect soil-water at the 150 cm depth, but were large enough to be
certain that annual plots were not affected by grass plots, etc.
Rainfall was monitored with a weighing rain gauge located 0.3 km from
the plots. Wastewater application was calculated from pumping records and
measured discharge rates of sprinklers on the site. No runoff was observed
at the sampled plots when irrigated at the hourly rates used in 1976 and
69
-------
1977. Evapotranspiration and groundwater recharge were calculated by the
mass balance approach of Thornthwaite and Mather.9
Effluent was analyzed for NO.J-N, NH^-N, organic N, total P, pH, Cl,
Na, K, Ca, and Mg. Soil-water was analyzed weekly for NO -N, NH -N,
ortho-P, and Cl in 1976 and was analyzed on monthly composites for organic
N, Ca, Mg, Na, and K. All analyses followed standard techniques or modi-
fications described in Section 5.
RESULTS AND DISCUSSION
The effectiveness of crop plants in preventing nutrient escape from
effluent irrigated farms depends upon their ability to take up and immo-
bilize those nutrients until harvest permanently removes them. The monthly
applications of major plant nutrients (TABLE 6-2) of the effluent and
TABLE 6-2. MONTHLY AND YEARLY APPLICATIONS OF CROP NUTRIENTS AND SALTS ON
THE 7.5 cm/WEEK IRRIGATION RATE * (VALUES IN kg/ha UNLESS
OTHERWISE STATED)
Month
Effluent (cm)
K
Ca
Mg
Na
Apr 76
May 76
June 76
July 76
Aug 76
Sep 76
Oct 76
TOTAL
Apr 77
May 77
June 7 7
July 77
Aug 77
Sep 77
Oct 77
TOTAL
5.8
23.5
37.8
35.0
32.5
32.5
10.0
177.1
0.0
24.7
36.3
35.4
35.3
25.1
22.8
179.6
6.10
51.93
73.17
44.42
40.64
60.17
17.95
294.38
— —
49.20
34.86
49.31
37.88
25.64
33.77
230.65
1.27
14.57
11.43
5.28
10.43
10.55
3.82
57.35
__
16.15
9.14
9.72
8.98
6.13
8.36
58.48
5.59
132.50
49.39
35.22
32.16
34.90
10.83
300.59 1363
__
142.09
38.05
34.55
32.77
25.40
23.60
296.46 1034
450 1566
454 1765
**
Applications to the 2.5 and 5.0 cm/week treatments would be approxi-
mately one-third and two-thirds of these amounts, respectively.
Excludes precipitation input.
70
-------
fertilizer was fairly uniform, except for K where fertilization added
100 kg/ha at one time. The uniform application of plant nutrients pro-
vided by the effluent was well suited to the growth of and uptake by the
perennial grasses and legumes which were harvested three times per growing
season. However, the monthly application of effluent during May and June
provided considerably more of the nutrients than could be taken up by the
annuals in those months. The P and K in excess of uptake needs could be
expected to be retained by the soil. The excess nitrogen, however, would
likely be mineralized and nitrified and thus subject to leaching.
The concentration of mineral N in the soil-water (Figures 6-1 to 6-6)
verified the leaching which occurred with the annuals. Following the
planting of the corn and other annuals on week 21 of 1976 and week 18 of
1977, mineral N, almost entirely N03-N, sharply increased in the root zone
of the annuals (Figures 6-1 to 6-3). Nearly simultaneously, increases
occurred 150 cm below surface of the 5.0 and 7.5 cm/week applications
(Figures 6-5 and 6-6). At the 2.5 cm/week irrigation rate only a gradual
increase in mineral N concentration occurred at 150 cm (Figure 6-4). When
irrigated at 2.5 cm/week the net recharge during May and June averaged
16.8 cm, while it averaged 39.2 and 56.3 cm for the 5.0 and 7.5 cm/week
rates, respectively. The low recharge prevented leaching of the excess
mineral N from the topsoil to the groundwater. The inability of the annu-
als to use the excess N applied in these early growth months and the inabil-
ity of the soil to retain nitrate against the leaching pressure of the
higher application rates resulted in recharge of water containing nitrate
in excess of 10 mg/£.
Once the annuals began to take up the N, mineral N in soil-water in
the root zone (Figures 6-1 to 6-3) and subsequently at the 150 cm depth
(Figures 6-4 to 6-6) diminished rapidly. The annuals were as effective
as perennial grasses during this time in preventing N leaching. In fact,
growth of corn on the 2.5 and 5.0 cm/week plots was limited by availability
of N. At those irrigation rates, yields of the corn were 15 to 55% lower
than at the 7.5 cm/week rate. Any N lost by leaching or denitrification
would further widen the deficiency. Any decrease in yields due to N defi-
ciency would be expected to lower the uptake of P and other nutrients as
well.
71
-------
40.
o>
\30.
E
20.
cr.
LoJ
• ANNUAL
* LEGUME
• GRASS
o EFFLUENT
15 20 25 30 35 40 15 20 25 30
1976 WEEKS 1977
35
40
Figure 6-1: Weekly average mineral N concentrations in applied effluent and in soil-water
from the 15 cm depth of the 2.5 cm/week irrigation rate of the various crop types.
-------
U)
40.
o>
20.
a:
LJ
10.
• ANNUAL
A LEGUME
• GRASS
o EFFLUENT
15 20 25 30 35 40 15 20 25 30
1976 WEEKS 1977
35
40
Figure 6-2: Weekly average mineral N concentrations in applied effluent and in soil-water
from the 15 cm depth of the 5.0 cm/week irrigation rate of the various crop types.
-------
40_
±:30-
jf
Z20-
_J
a:
UJ
? 10.
15
• ANNUAL
* LEGUME
• GRASS
o EFFLUENT
20
25 30
1976
35
40 15
WEEKS
20
25 30
1977
35
40
Figure 6-3: Weekly average mineral N concentrations in applied effluent and in soil-water
from the 15 cm depth of the 7.5 cm/week irrigation rate of the various crop types,
-------
40_
0>
^20.
_J
<
or
UJ
iioj
15
• ANNUAL
A LEGUME
• GRASS
o EFFLUENT
20
25 30
1976
35 40 15 20
WEEKS
Figure 6-4: Weekly average mineral N concentrations in applied effluent and in soil-water
from the 150 cm depth of the 2.5 cm/week irrigation rate of the various crop
types.
-------
40J
o>30_
o>
,20.
• ANNUAL
A LEGUME
• GRASS
o EFFLUENT
30
35
1976
40 15 20
WEEKS
25 30
1977
35
40
Figure 6-5: Weekly average mineral N concentrations in applied effluent and in soil-water
from the 150 cm depth of the 5.0 cm/week irrigation rate of the various crop
types.
-------
40.
• ANNUAL
A LEGUME
• GRASS
o EFFLUENT
^ 30.
\
CP
a:
LJ
20 _
15
Figure 6-6: Weekly average mineral N concentrations in applied effluent and in soil-
water from the 150 cm depth of the 7.5 cm/week irrigation rate of the
various crop types.
-------
The mass balance for mineral N for the 1976-1977 water year (TABLE
6-3 to 6-5) pointed out the comparative effectiveness of the crop types
within each irrigation rate. At all three rates, the perennial grasses
effectively controlled N leaching. At the highest irrigation rate (TABLE
6-5) the 207 kg/ha of total N applied was less than the 377 kg N/ha re-
O
ported in harvest of reed canary grass in effluent irrigated pastures.
Growth and yields of the perennial grasses which included reed canary
grass, therefore, may have been limited by the availability of N especially
at the 2.5 and 5.0 cm/week irrigation rates. The 1976 and 1977 average
yields of the three grass species, in which the soil-water samples were
located, increased from 5.82 metric tons/ha at 2.5 cm/week to 8.80 and
10.73 metric tons/ha at the 5.0 and 7.5 cm/week levels, respectively.
Because the perennial grasses effectively removed mineral N, total annual
losses were less than 10 kg N/ha under all three irrigation rates (TABLES
6-3 to 6-5) and mineral N concentrations in the leachate never exceeded
5 mg N/Jl (Figures 6-4 to 6-6).
TABLE 6-3. MASS BALANCE FOR INORGANIC N FOR THE 2.5 cm/WEEK CROP SITE
(VALUES IN kg/ha)
Month
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 7 7
July 77
Aug 77
Sep 77
ANNUAL
% Input
Precipi-
tation
Input
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
28.00
Irrigation*
Input
5.56
0.00
0.00
0.00
0.00
0.00
0.00
29.55
11.71
13.95
12.40
6.77
79.94
78.00
Total
Input
7.08
0.59
0.38
0.28
4.65
2.05
3.00
29.91
14.72
15.24
14.17
10.12
102.19
100.00
Grass
Recharge
0.68
0.26
0.17
0.12
0.18
0.53
0.50
0.00
2.44
0.02
0.37
0.70
5.97
6.00
Legume
Recharge
2.40
0.87
0.49
0.31
0.43
1.08
0.83
0.00
3.05
0.06
2.60
2.90
15.02
15.00
Annuals
Recharge
1.07
0.50
0.38
0.31
0.56
1.96
2.18
0.00
7.74
0.10
3.21
3.97
21.98
22.00
"Irrigation" input includes 22.4 kg N/ha added in fertilizer.
78
-------
TABLE 6-4. MASS BALANCE FOR INORGANIC N FOR THE 5.0 cm/WEEK CROP SITE
(VALUES IN kg/ha)
Month
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 77
July 77
Aug 77
Sep 77
ANNUAL
% Input
Precipi-
tation
Input
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
17.00
Irriga-
tion
Input*
8.23
0.00
0.00
0.00
0.00
0.00
0.00
35.77
21.80
28.87
24.77
13.30
132.74
86.00
No Vegeta-
Total
Input
9.75
0.59
0.38
0.28
4.65
2.05
3.00
36.13
24.81
30.16
26.54
16.65
154.99
100.00
tion
Recharge
8.53
2.54
1.76
1.41
2.49
8.62
9.27
13.70
63.78
28.57
56.43
37.04
234.14
177.00**
Grass
Recharge
1.75
0.43
0.24
0.15
0.20
0.50
0.36
1.28
1.99
0.59
0.74
1.12
9.35
6.00
Legume
Recharge
3.19
0.58
0.34
0.23
0.34
0.97
0.86
2.55
6.61
3.05
13.65
6.24
38.61
25.00
Annuals
Recharge
4.35
1.15
0.70
0.52
0.80
2.43
2.37
8.68
36.65
13.00
10.22
7.94
88.81
57.00
"Irrigation"
input includes 22
**
Total Input for the no
they
were not
TABLE 6-5. MASS
.4 kg N/ha
added in
vegetation plots was only
fertilizer
•
132.59 kg N/ha since
fertilized.
BALANCE FOR INORGANIC N FOR
(VALUES IN kg
N/ha)
THE 7.5
cm/WEEK CROP SITE
Month
Oct 76
Nov 76
Dec 76
Jan 77
Feb 77
Mar 77
Apr 77
May 77
June 7 7
July 77
Aug 77
Sep 77
ANNUAL
% Input
Precipi-
tation
Input
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
12.00
Irriga-
tion
Input*
12.34
0.00
0.00
0.00
0.00
0.00
0.00
42.39
32.65
42.27
36.15
19.72
185.52
89.00
Total
Input
13.86
0.59
0.38
0.28
4.65
2.05
3.00
42.75
35.66
43.56
37.92
23.07
207.77
100.00
No Vegeta-
tion
Recharge
10.55
2.08
1.27
0.90
1.42
4.38
4.21
16.16
50.03
21.08
35.22
45.91
193.21
104 . 00**
Grass
Recharge
3.15
0.55
0.28
0.17
0.20
0.38
0.13
0.49
0.18
0.42
0.77
0.74
7.46
4.00
Legume
Recharge
8.87
1.70
1.00
0.69
1.04
3.04
2.75
5.40
12.75
10.59
14.64
9.86
72.33
35.00
Annuals
Recharge
10.55
2.19
1.32
0.96
1.55
4.90
4.84
25.36
50.08
23.06
23.76
14.41
162.98
78.00
"Irrigation" input includes 22.4 kg N/ha added in fertilizer.
Total Input for the no vegetation plots was only 185.37 kg N/ha since
79
they were not fertilized.
-------
With the perennial legumes, nitrate in the root zone increased to
concentrations greater than 10 mg/£ immediately following each harvest
(Figures 6-1 to 6-3). The effect was short lived. As the plants recovered
they again removed much of the added N and, overall, were effective in
preventing excess nitrate leaching at all three irrigation rates (Figures
6-4 to 6-6 and TABLES 6-3 to 6-5). Because the legumes could fix N to make
up any deficiency caused by low applications, yields were not affected by
N levels. Rather the higher irrigation rates increased disease problems
and lowered yields. The 1976-1977 average annual yields were 13.69, 12.10
and 10.17 metric tons/ha for the 2.5, 5.0 and 7.5 cm/week irrigation rates,
respectively.
Mass balances (TABLE 6-3 to 6-5) point out that the annuals were much
less effective over the year in preventing N from escaping the treatment
site and that the effectiveness decreases with increasing irrigation rates.
With no vegetation (TABLE 6-4 and 6-5), the amounts of N which leached
past the 150 cm depth actually exceeded the amounts applied during the
1976-1977 water year. This treatment demonstrates the importance of the
vegetation in preventing N from moving with recharge water.
Organic N and orthophosphate concentrations were (TABLES 6-6 and 6-7)
measured during 1976 in soil-water samples. Organic N plus ammonium N
concentrations decreased slightly with depth. There was no significant
differences among either irrigation rates or crop type. Orthophosphate
concentrations were low in both topsoil and subsoil. At the 15 cm depth
average P concentrations were slightly higher in annual and no vegetation
treatments and levels were near background levels observed in these soils.
In this third year of effluent and fertilizer application, the soil-plant
system is still effectively removing added P.
Soluble cations (TABLE 6-8) were also measured on monthly composites
of soil-water samples in 1976. They indicate that sodium had largely
equilibrated with the soil. The concentrations of Na in solution were
nearly as high as in the effluent. Potassium was being depleted by plants,
particularly the legumes in spite of the addition of 100 kg K/ha in the
fertilizer.
80
-------
TABLE 6-6. MEAN ANNUAL ORGANIC PLUS AMMONIUM NITROGEN CONCENTRATION IN
THE SOIL-WATER SAMPLES TAKEN FROM THE TOPSOIL AND FROM BELOW
THE ROOT ZONE OF THE CROPLAND IRRIGATION AREA, 1976
(VALUES IN mg N/A + ONE STD. DEV.)
TREATMENT
Irrigation Rate
(cm/week)
Vegetation
15 cm Depth
150 cm Depth
2.5
5.0
7.5
Annuals
Legumes
Grass
Annuals
Legumes
Grass
No Crop
Annuals
Legumes
Grass
No Crop
2.28 + 0.67
2.15 + 0.90
1.73 + 0.63
1.63 + 0.42
2.00 + 0.78
1.30 + 0.19
1.07 + 0.35
1.54 + 0.51
1.99 + 0.61
1.48 + 0.45
1.54 + 0.73
1.29 + 1.11
1.15 + 0.43
0.84 + 0.41
0.84 + 0.35
1.06 + 0.71
0.76 + 0.17
0.32 + 0.24
0.66 + 0.60
0.94 + 0.82
0.66 + 0.38
0.89 + 0.25
TABLE 6-7. MEAN ANNUAL ORTHOPHOSPHATE CONCENTRATION IN THE SOIL-WATER
SAMPLES TAKEN FROM THE TOPSOIL AND FROM BELOW THE ROOT ZONE,
1976 (VALUES IN mg P/A + ONE STD. DEV.)
TREATMENT
Irrigation Rate
(cm/week)
Vegetation
15 cm Depth
150 cm Depth
2.5
5.0
7.5
Annuals
Legumes
Grass
Annuals
Legumes
Grass
No Crop
Annuals
Legumes
Grass
No Crop
.074 + .083
.019 + .014
.040 + .050
.091 + .103
.032 + .076
.028 + .037
.128 + .142
.106 + .093
.053 + .063
.067 + .095
.218 + .160
.042 + .062
.025 + .019
.039 + .040
.082 + .084
.024 + .035
.041 + .069
.034 + .046
.023 + .034
.026 + .031
.018 + .027
.106 + .079
81
-------
TABLE 6-8.
MEAN ANNUAL CONCENTRATION OF CATIONS IN THE EFFLUENT AND IN THE SOIL-WATER SAMPLES
TAKEN FROM THE TOPSOIL AND FROM BELOW THE ROOT ZONE OF THE CROPLAND IRRIGATION AREAS
1976 (VALUES IN mg/£) '
oo
N5
Irrigation
Rate
(cm/week)
2.5
5.0
7.5
EFFLUENT
Vegetation
Annuals
Legumes
Grass
Annuals
Legumes
Grass
No Crop
Annuals
Legumes
Grass
No Crop
15 cm
Depth
11.7
2.7
5.5
11.7
2.7
8.9
7.3
7.4
3.8
8.2
14.3
10.4
K
150 cm
Depth
2.0
0.7
3.5
5.3
0.7
1.4
2.0
3.4
1.9
0.8
6.5
Ca
15 cm
Depth
81.5
64.9
79.3
78.1
62.2
50.7
24.2
41.9
53.0
46.0
28.5
79.7
150 cm
Depth
57.4
78.7
45.3
56.4
53.5
68.2
35.7
42.1
43.8
34.2
13.9
Me Ma
15 cm
Depth
14.6
10.2
10.7
14.9
10.7
12.0
5.5
10.3
14.6
11.9
8.0
25.8
150 cm
Depth
29.6
38.9
18.1
18.7
22.6
24.5
12.0
18.5
16.0
17.6
15.4
15 cm
Depth
64.4
79.5
67.0
99.8
88.4
87.2
98.1
87.3
100.0
86.1
112.3
88.8
150 cm
Depth
31.1
44.0
46.1
72.1
65.6
61.9
51.5
73.2
79.7
70.9
91.1
-------
CONCLUSIONS AND RECOMMENDATIONS
Nitrogen concentrations in soil-water of both the root zone and the
subsoil varied widely during the growing season. The type of crop and the
irrigation rate were related to the variation. The tall growing cool
season grasses commonly used in pastures and grass hay of the Great Lakes
Region effectively maintained N concentrations well below the 10 mg/fc
limit for NO,-N in drinking water. Discharges of N into the groundwater
during the May through October irrigation season were less than 10 kg N/ha
even at the 7.5 cm/week irrigation rate. Legumes were somewhat less effec-
tive than grasses in preventing discharge of N. Peak discharges occurred
briefly following each harvest. The summer annuals contributed the great-
est yearly N losses — from 22 kg N/ha for the 2.5 cm/week rate to 163 kg
N/ha for the 7.5 cm/week rates. At the 5.0 and 7.5 cm/week rates, most of
the yearly discharge of N occurred during the first seven weeks following
planting.
The results of this study demonstrate the need to adjust application
of total wastewater and fertilizer closely to both the crop uptake charac-
teristics and to the ability of crops to withstand excessive irrigation.
For example, the grasses in this study were limited in growth by lack of
N suggesting that irrigation could be started earlier, continued later,
and possibly increased beyond 7.5 cm/week for part of the year to maximize
application while maintaining a high degree of treatment. Increasing
wastewater additions to most of the legume varieties proved to be detri-
mental to yields and decreased the effectiveness of land treatment. While
most legumes would benefit from low weekly applications of wastewater,
higher irrigation rates would require use of disease resistant varieties.
Higher rates could be used if stands were maintained in a crop rotation
scheme for only two or perhaps three years. Management of wastewater
applications to annuals is more difficult because of their very short
period of uptake. To prevent excessive N leaching, N should be eliminated
from starter fertilizer and the weekly irrigation rate should be kept low
so that evapotranspiration prevents recharge of much of the added waste-
water until uptake increases. As uptake increases (after about 5-7 weeks),
the irrigation rate should be increased to provide sufficient nutrients
for weekly growth of the annuals.
83
-------
Several crops have been demonstrated as suitable for use in land
treatment for municipal wastewater; however, protection of groundwater
and surface water aquifers requires that these cropland systems be
managed intensively. Perennial grasses offer the most efficient N and P
uptake and removal with least management. The added economic benefits
to be derived from the legumes and annuals could make them attractive
alternatives even with the much more intensive management required if
they are used.
84
-------
REFERENCES
1. Clapp, C.D., D.R. Linden, W.E. Larson, and J.R. Nylund. Nitrogen
Removal from Wastewater Effluent by a Crop Irrigation System. In:
Land as a Waste Management Alternative, R.C. Loehr, ed. Ann Arbor
Science Pub., Inc., Ann Arbor, Michigan, 1977. pp. 139-150.
2. Palazzo, A.J. Land Application of Wastewater: Forage Growth and
Utilization of Applied N, P and K. In: Land as a Waste Management
Alternative, R.C. Loehr, ed. Ann Arbor Science Pub., Inc., Ann
Arbor, Michigan, 1977. pp. 171-180.
3. Hook, J.E. and L.T. Kardos. Nitrate Relationships in the Penn State
"Living Filter" System. In: Land as a Waste Management Alternative,
R.C. Loehr, ed. Ann Arbor Science Pub., Inc., Ann Arbor, Michigan,
1977. pp. 181-198.
4. Kardos, L.T. and W.E. Sopper. Renovation of Municipal Wastewater
Through Land Disposal by Spray Irrigation. In: Recycling Treated
Municipal Wastewater and Sludge through Forest and Cropland,
W.E. Sopper and L.T. Kardos, eds. The Pennsylvania State University
Press, University Park, Pennsylvania, 1973. pp. 148-163.
5. Ellis, B.C., A.E. Erickson, J.E. Hook, L.W. Jacobs and B.D. Knezek.
Cropping Systems to Remove Nutrients from Municipal Waste. Project
Completion Report G-00529201, U.S. Environmental Protection Agency,
Region V, Chicago, Illinois, 1978.
6. Karlen, D.L., M.L. Vitosh and R.J. Kunze. Irrigation of Corn with
Simulated Municipal Sewage Effluent. J. Env. Qual., 5:269-273, 1976.
7. Hortenstein, C.C. Chemical Changes in Soil Solution from a Spodosol
Irrigated with Secondary-Treated Sewage Effluent. J. Env. Qual.,
5:335-338, 1976.
8. Sutherland, J.C., J.H. Cooley, D.G. Neary and D.H. Urie. Irrigation
of Trees and Crops with Sewage Stabilization Pond Effluent in Southern
Michigan. In: Wastewater Use in the Production of Food and Fiber -
Proceedings. EPA-660/2-74-041, U.S. Environmental Protection Agency
Technical Series, 1974.
9. Thornthwaite, D.W. and J.R. Mather. Instructions and Tables for
Computing Potential Evapotranspiration and the Water Balance. Pubs.
in Climatology, Vol. 10. Laboratory of Climatology, Drexel Institute
of Technology, Centerton, New Jersey, 1967. pp. 185-311.
85
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SECTION 7
APPLICATION OF MUNICIPAL WASTEWATER TO FOREST LANDS
Thomas M. Burton and James E. Hook
INTRODUCTION
While the application of municipal wastewater on forests has been the
1 —9 fi
object of numerous studies, only very few of these studies have used a
mass balance approach. Even so, the evidence to date would suggest that
mature forests may not be the ideal place to recycle wastewater unless the
application rate is low, usually 2.5 cm per week or less. Higher applica-
tion rates often result in losses of nitrate-nitrogen to the groundwater
at concentrations greater than the 10 rag/£ U.S.E.P.A. interim drinking
water standard. Since most studies have not used the mass balance ap-
proach, it is difficult to ascertain whether dilution by precipitation
during winter months will result in yearly average concentrations below
10 mg N/£ or not. Thus, the feasibility of using forests for application
of municipal wastewater remains an open question. There are also some data
that suggest that during the initial operation of such forested land appli-
cation systems mineralization and leaching of the large quantities of or-
ganic nitrogen from the litter and humus can result in nitrate-nitrogen
contamination of groundwater. ' This question also needs to be studied
in more detail.
A mass balance study of nitrogen and phosphorus leaching from a
wastewater application site was initiated in a late successional beech-
sugar maple forest in southern Michigan in 1976 in order to provide better
data on the feasibility of such application.
86
-------
MATERIALS AND METHODS
Three 1.2 ha plots were established in a late successional forest dom-
inated by sugar maple and beech (75 and 11% dominance, respectively, of
>10 cm trunk diameter with 423 trees/ha and a mean basal area of 42 m /ha).
More detailed vegetation descriptions are available from Knobloch and Bird's
area A27 and from Frye.28'29 One of these plots served as a non-irrigated
control, another received 5 cm/week of chlorinated, secondary municipal
wastewater from East Lansing, Michigan, and a third received 10 cm/week
wastewater.
The soils underlying the sites were described by high intensity map-
ping.30 The control and 5 cm/week plots are predominantly Miami-Marlette
and Kalamazoo loams. These are well drained soils formed on glacial till
materials. The Kalamazoo contains more sands and gravels than the Miami-
Marlette. The 10 cm/week plot is principally Owosso sandy loam with some
Brookston and Conover loams. The Owosso is well to moderately well drained
and is developed in sandy loam overlying a loam to clay loam soil at 45 to
105 cm depth. The Brookston and Conover loams are poorly drained.
Wastewater was applied twice weekly to the forest floor at the rate
of 8.4 mm/hr with Buckner 8600 agricultural spray nozzles from May 4 through
October 13, 1976, and from April 19 through October 28, 1977.
Wastewater was sampled from each application with acid-washed poly-
ethylene funnel collectors placed one meter above the forest floor. Porous
cup vacuum-type tube lysimeters were installed at 10 sites in each plot at
15, 30, 60, 90, 120 and 150 cm depths and sampled weekly during the irriga-
tion period by evacuating to 0.8 atmospheres and sampling 48 hours later
for most sites or by evacuating a week in advance on a few of the drier
sites on the 5 cm/week wastewater area and on all the control sites. The
lysimeters were also sampled as often as possible throughout the winter.
Runoff from the site was sampled with ISCO sequential samplers on an
event basis; these event samples were supplemented by several grab samples
each week. Runoff from an adjacent upstream field into the woods was also
monitored and runoff from the site during spring runoff and a few large
storms was corrected for inputs from this source. Discharge into and from
the site was calculated from stage-discharge relationships and monitored by
Stevens Type F recorders and V-notch weirs.
87
-------
Rainfall on the site was monitored with recording rain gauges located
in adjacent oldfields. Wastewater application was calculated from pumping
records and monitored in the field with wedge-shaped plastic "Tru-check"
rain gauges. Evapotranspiration and recharge were calculated using Thorn-
thwaite and Mather's technique.31
Soil-water and runoff samples were analyzed for NO -N, NO.-N, NH/-N,
organic-N, total P, and chloride in both years. Molybdate reactive P, Ca,
Mg, Na, and K were analyzed in 1976 on at least a monthly basis. Effluent
samples were analyzed for all parameters in 1976 and 1977. All N and P
analyses were done with standard autoanalyzer techniques32 in 1977. In
1976, N03-N, NH^-N, and Cl were analyzed with ion-selective electrodes;
Cl was analyzed by electrode in 1977. Cations and heavy metals were ana-
lyzed using atomic adsorption spectrophotometry.
Soil samples were taken before irrigation in 1976 and after irrigation
ceased in 1976 and 1977. The pre- and post-irrigation 1976 samples were
analyzed for Bray extractable P, N03-N, NH4-N (post-irrigation only), Cl,
Ca, Mg, Na, and K using standard soil analysis techniques33 or modifica-
tions as described in the methods section of Section 5.
RESULTS AND DISCUSSION
Nitrogen
The emphasis in this study was on nitrogen since many of the already
cited studies indicated that nitrate leaching was the major obstacle
in utilization of forests for wastewater application. An unexpected find-
ing was that inorganic concentrations were very high in soil-water in the
non-irrigated control (Figure 7-1) compared to most reported literature val-
ues for either soil-water or stream water draining undisturbed forests.34"39
This phenomenon may have been the result of lower than average rain-
fall resulting in very little water being available for runoff or recharge
(TABLE 7-1). High concentrations of N03-N in soil-water in arid or semi-
arid regions due to lack of leaching and to capillary rise from the subsoil
are well documented.40 Thus, nitrate can be expected to build up during
drought years and be "flushed out" in wet years in areas like Michigan
where evapotransportation in an average year is only slightly less than
88
-------
28.
26.
24.
22
f= 18
g1 16
z 14
s
12
10
8
6
FOREST-1976
Non Irrigated Control
— Sol I-Water Inorganic N
150 cm Depth
— Soil-Water Inorganic N
15 cm Depth
2 "6 ',0
J F
18 22 26 30
M J J
WEEK/MONTH
34
A
38 42 46 50
S 0 N D
22.
20.
18.
16.
114.
\
ZI2.
O"
EIO.
z
"I 8
o
!6
4
2
Figure 7-1:
FOREST- 1977
• Non Irrigated Control
, — Soil-Water Inorganic N
' 150 cm Depth
, — Soil-Water Inorganic N
' 15cm Depth
—*
V
v
M
11
i i
I I
I I
*"\
? f
WEEK/ MONTH
Inorganic N concentrations in soil-water at the 150 cm depth
for the non-irrigated forest area.
89
-------
TABLE 7-1. WATER BUDGET FOR NON-IRRIGATED FOREST (VALUES IN m3/ha)
Month
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
TOTALS
% of Input
Precipitation
520.7
201.9
129.5
96.5
159.2
701.0
1027.9
124.5
1030.4
442.0
607.1
1148.1
6188.8
100
Evapotranspiration
285.0
0
0
0
0
184.5
504.0
994.5
1060.4
1152.0
917.1
811.2
5908.6
95.47
Runoff
0
0
0
0
0
0
52.4
0
0
0
0
0
52.4
0.85
Recharge
0
0
0
0
0
0
50.5
0
0
0
0
0
50.5
0.82
precipitation. Winter precipitation can be very important in this respect
since the buildup of snow usually results in saturated soil conditions with
some recharge during the spring. Thus, areas with similar amounts of an-
nual precipitation but much greater snowfall than the 130 cm typical of the
study area, would not be expected to show buildup of NO -N. Low NO -N con-
centrations in soil-water have previously been reported for northern lower
Michigan and Minnesota forests.35'37
The consequences of the N03-N accumulation are of major importance to
quality of groundwater recharge since at least the first flush of soil-
water to groundwater could exceed the 10 mg N/£ drinking water standard.
A further consequence of the high inorganic N concentrations in the
soil-water from the non-irrigated control plots is that comparisons on a
concentration basis of wastewater irrigated plots to non-irrigated controls
or to pre-irrigated soil-water values are not meaningful since pre-irriga-
ted soil-water concentrations of N03-N were as high as wastewater values.
Thus, comparisons must be made on a mass balance basis. On this basis,
90
-------
over 99% of input inorganic nitrogen was retained on the non-irrigated
site in the 1976-77 water year. The only recharge or runoff occurred
during April (TABLE 7-1) with only 0.17 kg N/ha of the 22.25 kg N/ha input
from precipitation leaching from the site.
The mass balances for inorganic N for 1976-77 for 5 and 10 cm/week of
wastewater irrigation (TABLES 7-2 and 7-3) show marked differences between
the two sites. The 5 cm/week site retained very little of the added inor-
ganic N (TABLE 7-2) and most leached past the 150 cm depth. This ground-
water leaching was equivalent to 85% of the 190 kg/ha input. This figure
assumes no runoff from this site. This assumption is based on on-site
observations and chloride data. After spray began in May, 1976, it took
until late September before soil-water chloride values at the 150 cm depth
approached equilibrium with input chloride concentrations corrected for
evapotranspiration (Figure 7-2). Using the chloride dilution to calculate
the size of the soil-water storage pool for both the 5 and 10 cm/week areas
strongly suggested that almost all runoff originated from the 10 cm/week
plot and that all water from the 5 cm/week area percolated to groundwater.
The chloride concentration increases with depth and time for the two sites
were almost identical (Figure 7-2). This suggests that about the same
amount of water percolated to depth for both sites. Therefore, the infil-
tration rate for the forest would appear to be about 5 cm/week with excess
water running off the site. Thus, the 15% retention (renovation) of inor-
ganic N by the 5 cm/week site (TABLE 7-2) appears accurate. This figure is
very close to the 17% retention reported for a nine year study in Pennsyl-
vania .
Concentrations of inorganic N for the 5 cm/week site also indicate
that little removal had taken place (Figure 7-3). Interpretation of this
figure has to include the fact that chloride values did not approach input
concentrations until September, 1976. Thus, wastewater input on this site
was diluted by the existing soil-water pool until that time. Even so, con-
centrations at the 150 cm (output) depth were similar to input concentra-
tions (Figure 7-3) in 1976. These concentrations were probably a result of
the original high inorganic N concentrations (Figure 7-1) and increased
mineralization and leaching of the native organic N pool. It is noteworthy
that dilution by the existing soil-water pool extends over such a long
91
-------
VO
N)
FOREST- 1976
CHLORID?" WASTEWATER APPLICATION
FOREST- 1976
lOcm/WEEK WASTEWATER APPLICATION
CHLORIDE
Figure 7-2: Chloride concentrations as a function of depth and time for the Forest Irrigation Site.
-------
TABLE 7-2. MASS BALANCE FOR INORGANIC NITROGEN (N03+ N02 + OT^-N) FOR THE
5 CM/WEEK FOREST IRRIGATION SITE (VALUES IN KG/HA)
Month
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
ANNUAL
% of Input
Precipitation*
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
11.73
Wastewater
Irrigation
26.80
0
0
0
0
0
11.28
18.79
21.70
33.20
30.47
25.19
167.43
88.27
Total
Input
28.32
0.59
0.38
0.28
4.65
2.05
14.28
19.15
24.71
34.49
32.24
28.54
189.68
100.00
Recharge
29.94
2.45
1.55
1.12
1.85
5.22
19.58
10.93
18.40
15.12
21.49
34.19
161.84
85.32
Retention
-1.62
-1.86
-1.17
-0.84
2.80
-3.17
-5.30
8.22
6.31
19.37
10.75
-5.65
27.84
14.68
Based on mean literature values for Michigan.
TABLE 7-3. MASS BALANCE FOR INORGANIC NITROGEN (N03 + N02 + NHA-N) FOR
THE 10 CM/WEEK FOREST IRRIGATION SITE (VALUES IN KG/HA)
Month
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
ANNUAL
% of Input
Precipi-
tation*
1.52
0.59
0.38
0.28
4.65
2.05
3.00
0.36
3.01
1.29
1.77
3.35
22.25
6.85
Wastewater
Irrigation
47.43
0
0
0
0
0
20.48
34.96
42.69
56.20
53.73
46.88
302.37
93.15
Total
Input
48.95
0.59
0.38
0.28
4.65
2.05
23.48
35.32
45.70
57.49
55.50
50.23
324.62
100.00
Runoff
10.65
1.97
0
0
0
1.94
7.29
8.08
9.95
8.56
7.96
15.40
71.80
22.12
Recharge
4.19
0
0.42
0.26
0.35
0
2.19
4.12
5.80
2.39
2.47
0.70
22.89
7.05
Retention
34.11
-1.38
-0.04
0.02
4.30
0.11
14.00
23.12
29.95
46.54
45.07
34.13
229.93
70.83
Based on mean literature values for Michigan.
93
-------
22
20
18
16
o>
~ 14
z
0.12
E
z 10.
o
0>
_c
4.
2.
FOREST - 1976
5cm/Week Wastewater Application
Soil-Water Inorganic N t
150 cm Depth ,'
Wastewater Inorganic N '
2 6 10 14
J F M
M22' f' f A34
WEEK/MONTH
T—|-P—T—
42 46 50
0 N D
22
20.
18.
16.
fc 14.
01
eio.
Z8.
o
o
a>
L_
o
•E 4.
2.
FOREST - 1977
5 cm/week Wastewater Application
— Soil-Water Inorganic N 150cm Depth
— Wastewater Inorganic N
WEEK/MONTH
Figure 7-3.
Inorganic N concentrations in soil-water at the 150 cm depth
tor the 5 cm/week forest wastewater application area.
94
-------
period (May to November) and would indicate that any evaluation of land
treatment of wastewater based on the first year of application is meaning-
less. Similar lag times were reported for the Pennsylvania studies. Thus,
all mass balances presented here are for the 1976-77 water year after the
soil-water was in equilibrium with input wastewater chloride concentrations.
The mass balance for inorganic N for the 10 cm/week wastewater appli-
cation site (TABLE 7-3) presents a markedly different picture. Retention
of nitrogen (wastewater renovation) is 71%. As discussed above, all runoff
probably originated from this site. Thus, 22% of input inorganic N ran off
from this site (TABLE 7-3) representing an annual loss of 72 kg/ha. The
71% retention is probably the result of denitrification on this water
logged site since inorganic N concentrations at the 150 cm output depth
were much lower than input concentrations (Figure 7-4). Cl/N ratios sup-
port this contention. The Cl/N ratio varied between 5 and 10 for waste-
water input in 1976 and 1977. The Cl/N ratio increased only slightly to
between 6 and 14 at the 150 cm depth on the 5 cm/week site indicating lit-
tle on-site retention; but it increased to 30 for the 10 cm/week site by
the end of 1976, and it increased to 240 by the end of 1977, indicating sub-
stantial on-site retention of inorganic N. Thus, this site appears to be
very efficient at wastewater renovation based only on concentration, but
this efficiency is achieved at the cost of high runoff losses of N (and P
as will be discussed later).
While the above calculations include all inorganic N, almost all input
and output of inorganic N was as N03-N (Figure 7-5) although NH4~N was a
significant portion of input on certain occasions (TABLE 7-4).
Organic N mass balances for the 5 and 10 cm/week wastewater sites
(TABLES 7-5 and 7-6) show that the 5 cm/week site retains most of the or-
ganic N (87%) with only 13% of input leaching to groundwater. The 10 cm/
week site loses 58% or 66 kg organic N/ha in runoff, so retention is lower
(38%). Only 4% leaches past the 150 cm depth as organic N. The retained
N for both sites must have been immobilized as organic N or mineralized to
inorganic N and stored in soil solution or lost by denitrification. Run-
off losses of organic N from the 10 cm/week site are similar to water
losses (TABLE 7-7) indicating little denitrification, vegetation uptake,
95
-------
22
20
18
E 12
z
o 10.
S* 8
o
~ 6.
4.
2.
FOREST- 1976
10 cm/Week Wastewater Application
Soil-Water Inorganic N
150 cm Depth • f
Wastewater Inorganic N
A
^ A
2
J
1 6
F
10
M
' 14 I'E
A
M
VA/CT
' 261
J
' 301
J
34 '
A
38
S
'42
0
'46 '
N
'50
D
22
20
18
FOREST-1977
lOcm/Week Wastewater Application
Soil-Water Inorganic N
150 cm Depth
Wastewater Inorganic N
10 14 18 22 26 30 34 38
MAM J J A S
WEEK/MONTH
I' 'I' ' I'
42 46 50
0 N D
Figure 7-4: Inorganic N concentrations in soil-water at the 150 cm depth
for the 10 cm/week forest wastewater application area.
96
-------
22.
20.
18.
16.
14.
S 12.
S
iio.
EFFLUENT QUALITY
5 cm/Week Area
••—• 1977 Inorganic N
*—•» 1977 N03-N
* » 1976 Inorganic N
» »I976 N03-N
' ' I ' • I ' 'I
2 6
J F
10 14 18 22 26 30 34 38 42 46 50
MAMJJA SOND
WEEK/MONTH
2E.
20.
18
16
4
114
2
Soil-Water N03-N
5 cm/Week Wastewater
150cm Depth
1976
1977
22.
20.
18.
16.
S
= 14.
10.
>
6
4
2.
'10 14
Soil-Water N03-N
10 cm/Week Wastewater
150 cm Depth
1976
1977
T"
18
22
T — T1
26 30
34
A
38 42 46 50
S 0 N D
T"
T
10 14 18 22 26 30
MAM J J
WEEK/MONTH
' I ' 'I' 'I ' ' I ' '
34 38 42 46 50
A S 0 N D
Figure 7-5: Concentrations of nitrate and total inorganic N in wastewater input and nitrate-N in
soil-water samples for the forested sites.
-------
TABLE 7-4. MONTHLY AVERAGE WASTEWATER INPUT CONCENTRATIONS FOR THE 5 CM/WEEK SPRAY SITE
(VALUES IN MG/Jl)
00
Month
1976
May
June
July
August
September
October
1977
April
May
June
July
August
September
October
N03
10.60
20.07
7.89
8.81
15.51
14.21
8.13
4.32
4.53
12.33
11.23
9.01
13.26
-N
+ 6.24
+ 1.20
+ 5.44
+ 3.83
+ 3.15
+ 6.81
+ 2.61
+ 2.38
+ 1.95
+ 1.85
+ 1.24
+ .75
+ 2.58
N02-N
—
0.03 +
2.28 +
0.99 +
1.41 +
0.12 +
0.11 +
0.17 +
0.34 +
0.30 +
0.32 +
0.49 +
0.22 +
—
.03
2.84
.99
2.05
.14
.04
.05
2.30
.32
.19
.31
.15
NH4-N
1.88 +
0.36 +
4.66 +
3.81 +
2.05 +
1.13 +
1.50 +
3.60 +
3.45 +
0.07 +
0.13 +
0.14 +
0.12 +
1.40
.28
3.84
2.10
1.76
1.62
1.47
2.19
2.45
.05
.08
.09
.10
Organic N
1.32 +
1.02 +
0.70 +
0.78 +
1.05 +
0.99 +
1.77 +
2.41 +
6.26 +
3.29 +
3.13 +
2.77 +
2.74 +
.47
.37
.43
.49
.67
.75
.76
.99
4.28
1.72
2.18
1.43
.78
Total
3.06 +
3.91 +
1.63 +
3.73 +
4.06 +
3.61 +
3.30 +
2.55 +
2.27 +
3.50 +
2.55 +
2.29 +
3.80 +
P
.80
.58
.56
.71
.58
2.21
.56
1.43
1.84
2.61
.88
.76
.71
Chloride
91 + 12
101 + 10
119 + 24
116 + 18
132 + 15
113 + 3
117 (1)
122 + 12
128 + 9
123 + 21
105 + 15
114 + 21
131 + 12
-------
TABLE 7-5. MASS BALANCE FOR ORGANIC NITROGEN FOR THE 5 CM/WEEK FOREST
IRRIGATION SITE (VALUES IN KG/HA)
Month Precipitation*
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
ANNUAL
% of Input
1.54
0.60
0.39
0.28
4.71
2.08
3.04
0.36
3.05
1.31
1.79
3.40
22.55
31.20
Wastewater
Irrigation
1.73
0
0
0
0
0
2.05
5.59
16.34
8.60
8.17
7.24
49.72
68.80
Total
Input
3.27
0.60
0.39
0.28
4.71
2.08
5.09
5.95
19.39
9.91
9.96
10.64
72.27
100.00
Recharge
0.86
0.09
0.04
0.04
0.08
0.19
0.94
0.66
2.00
0.83
1.46
2.51
9.70
13.42
Retention
2.41
0.51
0.35
0.24
4.63
1.89
4.15
5.29
17.39
9.08
8.50
8.13
62.57
86.58
Calculated from mean inorganic N data from Michigan by assuming that
50.34% of total N input is organic N (Hoeft et_ al. , 1972).41
TABLE 7-6. MASS BALANCE FOR ORGANIC NITROGEN FOR THE 10 CM/WEEK FOREST
IRRIGATION SITE (VALUES IN KG/HA)
Month
Wastewater Total
Precipitation* Irrigation Inputs
Runoff Recharge Retention
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
ANNUAL
% of Input
1.54
0.60
0.39
0.28
4.71
2.08
3.04
0.36
3.05
1.31
1.79
3.40
22.55
19.78
3.53
0
0
0
0
0
5.37
8.85
28.37
15.50
13.04
16.82
91.48
80.22
5.07
0.60
0.39
0.28
4.71
2.08
8.41
9.21
31.42
16.81
14.83
20.22
114.03
100.00
5.46
0.18
0
0
0
2.03
8.43
10.17
8.42
8.31
8.29
14.93
66.22
58.07
0.35
0
0.04
0.03
0.06
0
0.25
0.57
1.16
0.70
0.94
0.33
4.43
3.88
-0.74
0.42
0.35
0.25
4.65
0.05
-0.27
-1.53
21.84
7.80
5.60
4.96
43.38
38.04
* Calculated from mean inorganic N data for Michigan by assuming that
50.34% of total N input is organic N (Hoeft elt al. , 1972).41
99
-------
TABLE 7-7. WATER BUDGET FOR THE 10 CM/WEEK FOREST IRRIGATION SITE (VALUES IN m3/ha)
o
o
Month
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
TOTALS
% of Inputs
Precipitation
520.7
201.9
129.5
96.5
159.2
701.0
1,027.9
124.5
1,030.4
442.0
607.1
1,148.1
6,188.8
16.49
Wastewater
Irrigation
3,497.6
0
0
0
0
0
2,304.2
4,660.1
5,244.1
5,217.9
5,217.6
5,208.6
31,350.1
83.51
Total
Inputs
4,018.3
201.9
129.5
96.5
159.2
701.0
3,332.1
4,784.6
6,274.5
5,659.9
5,824.7
6,356.7
37,538.9
100.0
Evapotranspiration
285.0
0
0
0
0
184.5
504.0
1,096.2
1,071.0
1,464.9
1,183.1
811.2
6,599.9
17.58
Runoff
2,570
468
0
0
6
945
2,306
2,554
2,921
2,645
2,457
4,755
21,627
57.61
Retention
1,164
-266
130
96
150
-428
522
1,114
2,282
1,549
2,185
791
9,289
24.74
-------
or soil storage has occurred prior to runoff. On the 5 cm/week site, 70%
of input water is recharged (TABLE 7-8) while only 13% (10 kg N/ha) of
organic N percolates to groundwater (TABLE 7-5). Thus, this site is effi-
cient at organic N removal.
On a total N basis, the 5 cm/week wastewater application area received
262 kg N/ha in the 1976-77 water year, retained 90 kg N/ha (34.5%), and
lost 172 kg N/ha (65.5%) to the groundwater by leaching. The 90 kg N/ha is
equivalent to an average of about 4.5 yg/g stored in the 150 cm soil pro-
file as mineral N. The average N03-N stored in the soil profile at the end
of 1976 was 5.8 pg/g (see TABLE 7-12 in discussion of soil samples below),
so the retention appears reasonable. The 10 cm/week area received 439 kg
N/ha, retained 273 kg N/ha (62%), lost 27 kg N/ha (6%) to the groundwater
by leaching, and lost 138 kg N/ha (31%) in runoff. Retention also includes
denitrification losses so is to some extent a misnomer but does indicate
the capacity of the site for wastewater renovation. Thus, the 5 cm/week
site is not very efficient at removal of N from wastewater (34.5%) while
the 10 cm/week area is efficient (62%) probably due to denitrification on
this water logged site. However, this efficiency is achieved at the cost
of substantial runoff losses of nitrogen (138 kg N/ha/yr) and phosphorus
as will be discussed later. It probably also is achieved at the cost of
reduced tree growth and eventual death (this is being studied now) because
of the anaerobic soils. Thus, these forests do not appear to be a reason-
able place to recycle wastewater with nitrogen concentrations in excess of
10 mg N/&.
Phosphorus
Mass balances for phosphorus for both the 5 and 10 cm/week wastewater
irrigation sites indicate excellent site retention of phosphorus (TABLES
7-9 and 7-10). This retention approaches 97% for the 5 cm/week site where
most water percolated to groundwater (TABLE 7-9). Retention for the 10 cm/
week irrigation site is only 66% with 33% of the added total P being lost
in runoff (TABLE 7-10). In fact, the flow weighted mean concentration in
runoff was 1.04 mg P/£ for the summer irrigation period and 0.90 mg P/fc for
the entire year. Peak concentrations in runoff often exceeded 1.0 mg P/&
101
-------
TABLE 7-8. WATER BUDGET FOR THE 5 CM/WEEK FOREST IRRIGATION SITE
(VALUES IN m3/ha)
Month
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
TOTALS
% of Input
Precipitation
520.7
201.9
129.5
96.5
159.2
701.0
1,027.9
124.5
1,030.4
422.0
607.1
1,148.1
6,188.8
28.31
Wastewater
Irrigation
1,747.5
0
0
0
0
0
1,157.8
2,321.1
2,609.7
2,613.2
2,608.8
2,613.5
15,671.6
71.69
Total
Inputs
2,268.2
201.9
129.5
96.5
159.2
701.0
2,185.7
2,445.6
3,640.1
3,055.2
3,215.9
3,761.6
21,860.4
100.0
Evapotrans-
piration
285.0
0
0
0
0
184.5
504.0
1,096.2
1,071.0
1,464.9
1,183.1
811.2
6,599.9
30.19
Recharge
1,983
202
130
96
159
517
1,682
1,349
2,570
1,590
2,033
2,950
15,261
69.81
TABLE 7-9. MASS BALANCE BUDGET FOR TOTAL PHOSPHORUS FOR THE 5 CM/WEEK
FOREST IRRIGATION SITE (VALUES IN KG/HA)
Month
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
ANNUAL
% of Input
Precipitation*
0.014
0.006
0.004
0.003
0.004
0.019
0.028
0.003
0.028
0.012
0.016
0.031
0.168
0.38
Wastewater
Irrigation
6.308
0
0
0
0
0
3.821
5.919
5.924
9.146
6.652
5.984
43.754
99.62
Total
Input
6.322
0.006
0.004
0.003
0.004
0.019
3.849
5.922
5.952
9.158
6.668
6.015
43.922
100.000
Recharge
0.151
0.009
0.003
0.003
0.008
0.018
0.076
0.066
0.252
0.162
0.222
0.549
1.519
3.46
Retention
6.171
-0.003
0.001
0
-0.004
0.001
3.773
5.856
5.700
8.996
6.446
5.466
42.403
96.54
* • — —
Based on literature value of 0.027 mg P/H for Michigan.
102
-------
TABLE 7-10. MASS BALANCE FOR TOTAL PHOSPHORUS FOR THE 10 CM/WEEK FOREST
IRRIGATION SITE (VALUES IN KG/HA)
Month
Wastewater
Precipitation* Irrigation
Total
Inputs Runoff Recharge Retention
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
ANNUAL
% of Input
0
0
0
.014
.006
.004
0.003
0
0
0
0
0
0
0
0
0
0
.004
.019
.028
.003
.028
.012
.016
.031
.168
.19
11.717
0
0
0
0
0
7.604
11.883
11.904
18.263
13.305
11.928
86.604
99.81
11.
0.
0.
0.
0.
0.
7.
11.
11.
18.
13.
11.
86.
100.
731
006
004
003
004
019
632
886
932
275
321
959
772
000
3
0
0
0
0
0
4
5
3
3
2
5
28
33
.422
.572
.125
.785
.138
.155
.244
.101
.880
.573
.995
.42
0.
0
0.
0.
0.
0
0.
0.
0.
0.
0.
0.
0.
0.
034
008
005
007
025
076
169
146
122
051
643
74
8
-0
-0
-0
-0
-0
3
6
8
15
10
6
57
65
.275
.566
.004
.002
.128
.766
.469
.655
.519
.028
.319
.335
.134
.84
for this hydraulically overloaded site. While this deliberate water log-
ging promoted denitrification, it resulted in significant losses of total
P (29 kg/ha/yr) at concentrations in excess of Michigan standards for
wastewater discharge. Thus, excessive irrigation of a site to promote
denitrification would require a very delicate balancing act with irrigation
at levels just high enough to maintain soil saturation but not high enough
to yield runoff. Perhaps, irrigation on a daily and site-specific basis
could achieve this goal, but the intensive monitoring and management re-
quired is likely to make this technique unacceptable to system operators.
Monthly total P concentrations at the 150 cm depth in both irrigation
areas were low and similar to non-irrigated control levels (TABLE 7-11)
through most of the year. There was a trend towards slightly elevated
concentrations late in the year in the irrigated areas, but these concen-
trations were still low. Thus, on both a mass balance and concentration
basis, these forested sites did an excellent job of removing P from perco-
lated wastewater. Management of forested systems in such a manner that
little or no runoff occurs would result in acceptable removal of P from
wastewater. Similar results have been reported by numerous other studies
i 2,4,7,8,10,14,16,19-21,23-26
for a wide variety of forest and soil types.
103
-------
TABLE 7-11. MONTHLY WASTEWATER INPUT AND OUTPUT (150 CM DEPTH) TOTAL P
CONCENTRATIONS FOR THE FORESTED SITES (ALL VALUES IN MG
Month
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
Wastewater
Input
3.61
—
—
—
—
—
3.30
2.55
2.27
3.50
2.55
2.29
Non-Irrigated
Control
N.S.*
0.028
N.S.
N.S.
N.S.
0.042
0.040
0.064
0.042
N.S.
N.S.
N.S.
5 cm/week
Wastewater
Irrigation
0.076
0.045
0.022
0.036
0.049
0.035
0.045
0.049
0.098
0.102
0.109
0.186
10 cm/week
Wastewater
Irrigation
0.029
0.048
0.063
0.053
0.043
0.044
0.047
0.068
0.074
0.094
0.056
0.065
N.S. designates No Sample, soil too dry.
The primary mechanism of this removal appears to be sorption on soil par-
ticles although some increased growth and P uptake has been documented.22
Soil Sampling
Soil sampling was conducted at each of the lysimeter sites before
irrigation began and after it ceased in 1976. Wastewater had not been
applied to these sites long enough to expect major changes in soil chemis-
try. Minor changes would be masked by the variability normally associated
with soil analysis from a glaciated area. Thus, it is not too surprising
that few significant trends are apparent in these soil analyses (TABLES
7-12 to 7-16). There is a possible trend of increased P in the 0-15 cm
increment (TABLE 7-13) and a significant increase in sodium and chloride
at all depths on the wastewater irrigated sites (TABLES 7-14, 7-16), but
no other clear cut trends are apparent. These data provide a baseline for
studies of long-term changes in soil chemistry.
104
-------
TABLE 7-12. NITRATE-NITROGEN ANALYSES OF SOILS FROM THE FOREST WASTEWATER
IRRIGATION STUDY
Depth-cm
0 cm/week
1975 1976
5 cm/week
1975 1976
10 cm/week
1975 1976
NITRATE-NITROGEN (yg/g dry soil)
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
14.4
2.9
2.2
1.8
2.2
1.8
2.1
1.5
2.4
2.0
3.3
NITRATE
34.6
14.1
9.8
8.2
10.2
9.0
9.6
8.1
10.8
9.9
12.4
8.3
6.0
4.3
3.8
3.8
3.9
3.1
3.0
3.3
3.4
4.3
NITROGEN
46.9
59.4
61.2
65.0
54.4
78.5
57.9
50.5
47.8
37.8
55.9
14.5
5.4
6.0
1.8
2.9
1.7
1.3
1.7
1.8
1.8
3.9
(yg/m£ of
48.1
34.5
52.1
10.0
22.4
13.8
9.1
12.9
11.9
12.2
22.7
11.6
6.0
5.4
5.6
5.3
4.9
4.7
5.7
4.3
4.5
5.8
soil-water)
27.9
26.5
32.9
37.2
36.3
33.6
35.0
36.2
34.6
33.5
33.4
5.3
11.3
5.4
1.7
2.5
3.1
2.3
1.7
1.8
1.1
3.6
17.7
57.0
38.7
11.5
14.6
16.6
12.5
8.5
11.9
6.8
19.6
6.5
4.8
4.4
4.3
4.1
3.9
3.9
4.4
4.1
3.7
4.4
14.7
21.7
26.6
24.4
22.4
24.2
24.0
29.2
27.0
25.5
23.9
105
-------
TABLE 7-13. BRAY EXTRACTABLE PHOSPHORUS AND AMMONIUM-NITROGEN ANALYSES OF
SOILS FROM THE FOREST WASTEWATER IRRIGATION STUDY. VALUES IN
pg/g DRY SOIL. (NOTE: NO 1975 DATA ON AMMONIUM-NITROGEN)
Depth-cm
0 cm/week
1975 1976
5 cm/week
1975 1976
10 cm/week
1975 1976
PHOSPHORUS
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
14.2 13.2
7.1 9.1
8.0 7.2
5.3 6.6
5.5 7.3
5.8 6.4
5.5 5.1
3.0 2.8
2.2 2.6
1.4 2.3
5.8 6.3
17.4
11.6
8.5
5.7
6.4
6.0
4.8
4.1
3.9
2.7
7.1
25.0
13.1
8.9
6.8
7.4
8.2
4.5
2.1
1.8
2.2
8.0
17.9 29.9
12.8 12.6
5.2 5.4
2.6 3.1
2.2 2.1
1.8 1.3
1.3 1.1
1.0 1.1
1.0 1.0
1.0 .8
4.7 5.8
AMMONIUM-NITROGEN
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
7.6
3.7
2.5
2.2
2.1
2.3
1.9
2.0
2.2
1.9
2.8
—
—
—
—
—
—
—
—
—
—
—
11.5
5.0
3.8
2.8
2.7
2.6
2.5
2.4
2.1
2.3
3.8
11.9
4.4
2.9
2.8
2.8
2.5
2.5
2.3
2.6
2.2
3.7
106
-------
TABLE 7-14. SODIUM AND POTASSIUM ANALYSES OF SOILS FROM THE FOREST
WASTEWATER IRRIGATION STUDY (VALUES IN yg/g DRY SOIL)
Depth- cm
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
0 cm/week
1975 1976
39.8
32.8
39.8
40.5
38.9
36.6
50.4
49.4
53.5
60.2
44.2
80.3
44.1
59.3
62.2
66.8
48.8
52.1
48.8
47.7
52.0
56.2
56.6
46.7
46.3
42.7
52.3
59.3
59.4
63.1
64.2
72.4
56.3
90.8
51.0
35.8
40.2
49.2
60.5
53.0
46.9
51.9
50.3
53.0
5 cm/week
1975 1976
SODIUM
56.1
46.5
47.6
46.2
39.8
40.8
40.2
41.7
48.6
46.4
45.4
POTASSIUM
62.9
32.4
39.7
48.6
44.6
41.8
35.5
36.8
40.7
38.0
42.1
158.0
90.3
74.9
82.8
78.4
80.9
78.6
89.9
89.1
81.6
90.4
96.4
55.5
37.0
55.7
46.9
47.6
43.4
49.7
43.5
42.6
51.8
10 cm/week
1975 1976
35.8
28.8
29.9
29.7
35.5
39.0
38.5
42.5
43.7
42.5
36.6
58.9
47.9
38.4
49.3
52.2
44.1
44.4
46.6
37.4
31.4
45.1
177.4
101.7
77.0
78.2
85.4
128.3
89.4
90.5
92.9
84.2
100.5
72.3
43.6
39.4
42.3
43.3
38.6
36.5
35.0
35.1
32.2
41.8
107
-------
TABLE 7-15. CALCIUM AND MAGNESIUM ANALYSES OF SOILS FROM THE FOREST
WASTEWATER IRRIGATION STUDY (VALUES IN yg/g DRY SOIL)
Depth-cm
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
0 cm/week
1975 1976
1808.3
679.3
683.9
803.2
858.6
996.8
1396.0
1873.0
1840.8
2771.3
1371.1
186.3
95.3
114.1
160.9
187.1
189.7
198.9
243.3
234.3
469.1
207.9
2020.3
901.5
742.5
798.2
927.3
1385.4
1298.3
1935.8
2076.4
2577.0
1466.3
214.9
87.5
86.0
128.5
188.2
236.5
236.1
231.7
239.5
279.9
192.9
5 cm/week
1975 1976
CALCIUM
1941.3
795.2
998.1
973.1
901.4
956.5
1304.2
1522.5
2211.6
1966.8
1357.1
MAGNESIUM
223.5
105.7
138.8
180.5
218.5
191.0
180.1
163.1
199.9
169.6
177.1
2497.1
1575.7
824.9
1007.1
945.0
1192.5
1359.9
2098.5
2013.8
2212.4
1572.7
330.6
218.3
109.0
158.1
168.7
206.0
206.5
208.1
173.1
166.6
194.5
10 cm/week
1975 1976
2284.4
982.3
905.9
1082.6
1326.1
1466.3
2094.1
2440.8
2938.0
2719.7
1824.0
220.3
128.4
175.5
257.7
285.9
260.1
269.2
267.6
204.1
168.9
223.8
2386.6
1094.5
946.8
1137.7
1777.2
2201.5
2649.4
2970.1
3047.4
2967.0
2117.8
351.0
180.0
213.1
249.0
251.1
221.9
201.8
190.3
179.6
140.5
217.8
108
-------
TABLE 7-16. CHLORIDE ANALYSES OF SOILS FROM THE FOREST WASTEWATER
IRRIGATION STUDY
Depth-cm
0
1975
cm/week
1976
5 cm/week
1975 1976
10 cm/week
1975 1976
CHLORIDE (yg/g dry soil)
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
9.8
7.4
8.2
7.5
9.7
7.1
9.6
7.4
10.0
9.3
8.6
26.9
39.1
37.6
35.3
44.8
37.0
43.3
40.2
48.3
45.6
39.8
16.9
14.3
12.5
13.1
12.8
13.8
12.7
14.4
14.6
16.3
14.1
CHLORIDE (yg/m£
99.1
144.2
173.4
217.6
183.5
248.4
227.4
236.1
219.4
191.3
194.0
8.2
8.2
8.1
8.4
11.0
8.8
11.4
11.2
13.9
9.5
9.9
47.5
32.0
26.0
27.0
28.7
26.2
26.1
31.5
28.3
28.7
30.2
11.2
9.2
11.2
10.0
10.2
11.4
10.9
10.2
12.0
10.3
10.7
46.8
30.3
27.1
26.6
29.4
30.4
29.5
26.5
27.3
23.3
29.7
of soil-water)
30.4
48.8
64.9
52.5
81.2
68.9
75.3
78.5
93.4
67.8
66.2
113.7
140.2
163.8
165.6
183.0
170.7
173.9
186.2
210.9
212.9
172.1
40.9
50.5
76.0
64.6
59.0
64.0
64.0
54.0
78.4
67.3
61.9
106.5
135.9
158.9
150.1
160.0
183.2
173.6
171.4
174.5
156.8
157.1
109
-------
Runoff Sampling
Data for loads of nutrients in runoff from the entire 18.4 ha sub-
watershed are included in TABLES 7-17 to 7-21. Loads were calculated
using the Beale ratio estimator technique adopted for all IJC studies.
Only 8.5 ha of this watershed is forested. Inputs from an upstream 7.73 ha
sub-watershed (TABLES 9-2 to 9-6) and 2.2 ha of downstream oldfield
areas are included. However, almost all of the runoff from 7.73 ha up-
stream station occurred during spring runoff (97%) and early summer (3%).
Water budget calculations (TABLE 7-1) for non-irrigated forests suggest
that any runoff from the non-sprayed forested areas occurred during April.
Thus, almost all runoff from the 18.4 ha "forested" sub-watershed except
during the spring period must have occurred as a result of wastewater irri-
gation. Furthermore, water budget and chloride dilution calculations sug-
gest that almost all of this water originated from the 1.2 ha site irri-
gated with 10 cm/week of wastewater. In mass balance calculations (TABLES
7-2,7-3,7-5,7-6,7-9,7-10), upstream inputs from the 7.73 ha baseline water-
shed were subtracted and the remainder assigned tc the 10 cm/week spray
site. Only 55% of water discharge originated from the forest during spring
runoff (58% of total area) so all areas may have been contributing during
this season. During other seasons, runoff had to have originated primarily
from the spray sites. The monthly mass balances (TABLES 7-2,7-3,7-5,7-6,
7-9,7-10) are likely to be affected significantly only during March and
April (92% of water from the 7.73 ha baseline watershed was discharged
during this period) with corrections made for input from upstream areas
and with the limited contribution expected from non-sprayed areas during
March and April (TABLE 7-1), the annual loading calculations from the spray
site must be substantially correct.
The unit area loads (TABLES 7-17 to 7-21) for this 18.4 ha sub-water-
shed are misleading since most of these loads originated from the 1.2 ha,
10 cm/week spray irrigation site. If this is the case, then maximum
annual exports from this 1.2 ha site are correct as listed in the mass
balances (TABLES 7-3,7-6,7-10).
110
-------
TABLE 7-17.
STREAM EXPORT OF MOLYBDATE REACTIVE PHOSPHORUS AND TOTAL PHOSPHORUS FROM THE 18.35 ha
FORESTED AREA*
Season
Fall, 1976
Winter, 1976-77
Spring Runoff, 1977
Spring Post Runoff
1977
Summer, 1977
Total 1976-77
Water Year
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff, 1977
Spring Post Runoff
1977
Summer, 1977
Total 1976-77
Water Year
% of Total
EVENT FLOW
Rising Descending
Hydrograph Hydrograph
(kg) (kg)
0.768 +
0
0.239 +
0.469 +
ND
0.529 +
0
0.309 +
2.234 +
2.415 +
5.487 +
14.
MOLYBDATE
0.002 1.944 + 0.028
0
0.001 1.894 + 1.853
0.000 ND**
ND
T 0 T A
.001 1.919 + 0.015
0
.001 2.315 + 2.026
.648 8.156 + 0.053
.059 9.746 + 3.114
.651 22.136 + 3.715
80 59.73
Non-Event
Flow (kg)
R E A C T I
0.076 + 0.000
0.031 + 0.091
0.255 + 0.094
0.279 + 0.000
ND
L P H 0 S
0.138 + 0.000
0.369 + 2.700
0.445 + 0.301
0.430 + 0.348
8.058 + 0.000
9.440 + 2.739
25.47
Export Total
(kg) % Total
V E P H 0
2.788 + 0.
0.031 + 0.
2.388 + 1.
P H 0 R U S
2.586 + 0.
0.369 + 2.
3.069 + 2.
10.820 + 0.
20.219 + 3.
37.063 + 4.
S P H 0 R U S
noo
DQ1
QCC
015 6.98
700 1.00
048 8.28
737 29.19
115 54.55
662
Unit
Area
Loads*
(kg/ha)
0.152
0.002
0.130
0.141
0.020
0.167
0.590
1.102
2.019
Most runoff originated from the 1.2 ha, 10 cm/week wastewater irrigation site so unit area loads
calculated for the entire site are misleading.
ND = no data
-------
TABLE 7-18. STREAM EXPORT OF NITRATE AND AMMONIA NITROGEN FROM THE 18.35 ha FORESTED AREA*
EVENT FLOW
Season
Rising
Hydrograph
(kg)
Descending
Hydrograph
(kg)
Non-Event
Flow (kg)
NITRATE-N
Fall, 1976
Winter, 1976-77
Spring Runoff, 1977
Spring Post Runoff
1977
Summer, 1977
Total 1976-77
Water Year
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff, 1977
Spring Post Runoff
1977
Summer, 1977
Total 1976-77
Water Year
% of Total
2.82 + 0
0
0.42 + 0
10.38 + 2
9.10+0
22.72+2
28.70
0.003 + .
0
0.121 + .
0.355 + .
1.308 + .
1.787 + .
32.06
.001
.002
.46
.35
.49
00001
0006
010
013
016
4.65
0
3.36
4.84
37.85
50.70
64
0.070
0
0.373
1.077
1.423
2.943
52
+ 0.10
+ 0.58
+ 0.35
+ 9.75
+ 9.78
.04
A M M
+ .001
+ .156
+ .019
+ .092
+ .182
.80
0.
0.
1.
0.
3.
5.
0 N
0.
0.
0.
0.
0.
0.
Oil + 0.
18 + 1.
73 + 0.
58 + 0.
25 + 1.
74 +2.
—
7.25
I A - N
0008 + 0
0012 + 0
065 + 0
110 + 0
667 + 2
844 + 2
15.14
Export Total
(kg)
% Total
Unit
Area
Loads*
(kg/ha)
I T R 0 G E N
00
14
33
00
80
16
I T R
.00
.00
.048
.011
.490
.490
7.48 +
0.18 +
5.51 +
15.80 +
50.21 +
79.17 +
0 G E N
0.074 +
0.001 +
0.559 +
1.542 +
3.398 +
5.574 +
0.10
1.14
0.66
2.49
9.92
10.31
0.001
0.000
0.163
0.024
2.492
2.497
9.45
0.23
6.96
19.96
63.42
1.33
0.02
10.03
27.66
60.96
100.00
0.408
0.010
0.300
0.861
2.736
4.315
0.004
0.00006
0.030
0.084
0.185
0.303
Most runoff originated from the 1.2 ha, 10 cm/week wastewater irrigation site so unit area loads
calculated for the entire site are misleading.
-------
TABLE 7-19. STREAM EXPORT OF NITRITE AND KJELDAHL NITROGEN FROM THE 18.35 ha FORESTED AREA *
u>
EVENT FLOW
Season
Fall, 1976
Winter, 1976-77
Spring Runoff, 1977
Spring Post Runoff
1977
Summer, 1977
Total 1976-77
Water Year
% of Totals
Fall, 1976
Winter, 1976-77
Spring Runoff, 1977
Spring Post Runoff
1977
Summer, 1977
Total 1976-77
Water Year
% of Totals
Rising
Hydrograph
(kg)
0.067 +
0
0.120 +
0.149 +
0.569 +
0.905 +
27.
0.507 +
0
2.045 +
12.276 +
6.094 +
20.922 +
21.
.0004
.0007
.016
.011
.019
25
0.0009
0.011
4.323
0.052
4.323
22
Descending
Hydrograph
(kg)
N I
0.136 +
0
0.205 +
0.225 +
1.561 +
2.127 +
64.
K J
2.070 +
0
7.297 +
12.138 +
38.904 +
60.409 +
61.
Non-Event
Flow (kg)
Export Total
(kg)
% Total
Unit
Area
Loads*
(kg/ha)
TRITE-NITROGEN
.003
.046
.023
.566
.568
05
ELD
0.011
2.549
0.119
4.200
4.914
26
0.004
0.007
0.104
0.060
0.114
0.289
A H L
0.149
0.472
1.529
2.554
12.578
17.282
+ 0.000
+ 0.000
+ 0.053
+ 0.004
+ 0.107
+ 0.119
_*_
8.70
-NIT
+ 0.000
+ 3.302
+ 0.450
+ 0.006
+ 0.000
+ 3.333
17.53
0.207
0.007
0.429
0.434
2.244
3.321
+ 0.003
+ 0.000
+ 0.070
+ 0.028
+ 0.576
+ 0.581
6.
0.
12.
13.
67.
23
21
92
07
57
0.011
0.0004
0.023
0.024
0.122
0.181
100.00
R 0 G E
2.726
0.472
10.871
26.968
57.576
98.613
N
+ 0.011
+ 3.302
+ 2.588
+ 4.325
+ 4.200
+ 7.345
2.
0.
11.
27.
58.
76
48
02
35
39
0.149
0.026
0.592
1.470
3.138
5.374
Most runoff originated from the 1.2 ha, 10 cm/week wastewater irrigation site so unit area loads
calculated for the entire site are misleading.
-------
TABLE 7-20. STREAM EXPORT OF CHLORIDE AND SUSPENDED SOLIDS FROM THE 18.35 ha FORESTED AREA*
Season
EVENT
Rising
Hydrograph
(kg)
FLOWS
Descending
Hydrograph
(kg)
Non-Event Export Total
Flow (kg) (kg)
Unit
% Area
Total Loads*
(kg/ha)
CHLORIDE
Fall, 1976
Winter, 1976-77
Spring Runoff '77
Spring Post Runoff
1977
Summer, 1977
Total 1976-77
Water Year
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff '77
Spring Post Runoff
1977
Summer, 1977
Total 1976-77
Water Year
% of Total
65.36 + 0.15
0
153.11 + 0.76
461.89 + 61.36
374.85 + 8.63
1055.21 + 61.97
19.67
11.25 + 0.06
0
ND
ND
ND
246.50 + 0.07
0
527.93 + 47.54
648.65 + 11.23
1857.92 + 98.56
3281.00 + 110.00
61.17
S U S P E N
21.39 + 0.39
0
ND
ND
ND
17.98 + 0.00 329.84 + 0.17
3.74 + 12.48 3.74 + 12.48
206.77 + 20.39 887.81 + 51.73
121.22 + 2.07 1231.76 + 62.41
677.39 + 93.12 2910.16 + 135.87
1027.10+96.16 5363.31+158.71
19.15
DED SOLIDS
1.14 + 0.00 33.78 + 0.39
TvrnA*
wn —
NT)
wn
6.15 17.97
0.07 0.20
16.55 48.38
22.97 67.13
54.26 158.59
292.28
1 0/.1
**
Most runoff originated from the 1.2 ha, 10 cm/week wastewater irrigation site so unit area loads
calculated for the entire site are misleading.
ND = no data
-------
TABLE 7-21. STREAM EXPORT OF SODIUM AND CALCIUM FROM THE 18.35 ha FORESTED AREA*
EVENT FLOWS
Season
Fall, 1976
Winter, 1976-77
Spring Runoff, 1977
Spring Post Runoff
1977
Summer, 1977
Total 1976-77
Water Year
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff, 1977
Spring Post Runoff
1977
Summer, 1977
Total 1976-77
Water Year
% of Total
Rising
Hydrograph
(kg)
48.95 + 0.60
0
92.06 + 3.66
ND
ND
44.00 + 0.52
0
228.17 + 9.09
ND
ND
Descending
Hydrograph
(kg)
157.79 + 2.13
0
188.06 + 15.67
ND
ND
130.73 + 0.17
0
530.66 + 2.43
ND
ND
Non-Event Export Total %
Flow (kg) (kg) Total
SODIUM
Go/--; i r\ f\r\ r\ o£7 -i- n nn
119.73~~+ 36.57 399.85 + 40.02
CALCIUM
2 on _L i Q £0 o on -u i Q AO
287.45 + 91.57 1046.28 + 92.05
JNLI ~* •"
Unit
Area
Loads*
(kg/ha)
0.02
21.79
0.120
57.018
Most runoff originated from the 1.2 ha, 10 cm/week wastewater irrigation site so unit area loads
calculated for the entire site are misleading.
ND = no data
-------
CONCLUSIONS/REMEDIAL MEASURES
In conclusion, older hardwood forests are not reasonable places to
practice wastewater irrigation if that wastewater has a higher concentra-
tion of inorganic N than the 10 mg N03~N/£ drinking water standard. Since
municipal wastewater typically has concentrations in excess of the 10 mg
N/£ standard, older forests should not be used for municipal wastewater
irrigation. An exception to this would be wastewater from lagoon systems.
Typically, aquatic plant production in lagoons raises the pH above 9.2,
the pK of ammonia gas, and nitrogen is lost to the atmosphere as ammonia
42
gas. During periods predominated by plant decay (e.g., crash of algal
blooms, self-shading and decreased water circulation as a result of high
macrophyte production), nitrogen is lost as a result of denitrification
under the existing anaerobic conditions. In either case, lagoons can be
managed so that there is excellent removal of nitrogen (D. King, personal
communication). Thus, a combined lake (lagoon)-land treatment system could
utilize forests for wastewater irrigation without NO--N contamination of
groundwater.
Also, excess application of wastewater can result in excellent denitri-
fication as shown by results from the 10 cm/week site and as suggested by
Kardos and Sopper for their hardwood site. This excess application would
have to be carefully controlled to prevent excessive runoff losses of N and
P. The intensive management required for this option coupled with likely
damage to tree growth and viability (unanswered questions at this time)
make this option unattractive.
116
-------
REFERENCES
1. Breuer, D. W., D. W. Cole and P. Schiess. Nitrogen Transformation and
Leaching Associated with Wastewater Irrigation in Douglas-Fir, Poplar,
Grass, and Unvegetated Systems. In: Municipal Wastewater and Sludge
Recycling on Forest Land and Disturbed Land, W. E. Sopper, ed.
Pennsylvania State University Press, University Park, 1978. (In press.)
2. Brockway, D. G., G. Schneider and D. White. Dynamics of Municipal
Wastewater Renovation in a Young Conifer-Hardwood Plantation in Michigan.
In: Municipal Wastewater and Sludge Recycling on Forest Land and Dis-
turbed Land, W. E. Sopper, ed. Pennsylvania State University Press,
University Park, 1978. (In press.)
3. Coats, R. N., R. L. Leonard and C. R. Goldman. Nitrogen Uptake and
Release in a Forested Watershed, Lake Tahoe Basin, California. Ecology,
57:995-1004, 1976.
4. Frost, T. P., R. E. Towne and H. J. Turner. Spray Irrigation Project,
Mt. Sunapee State Park, New Hampshire. In: Recycling Treated Municipal
Wastewater and Sludge Through Forest and Cropland, W. E. Sopper and L. T.
Kardos, eds. Pennsylvania State University Press, University Park, 1973.
pp. 371-384.
5. Hook, J. E. and L. T. Kardos. Nitrate Leaching During Long-Term Spray
Irrigation for Treatment of Secondary Sewage Effluent at Woodland Sites.
J. Env. Qual., 7(1):30-34, 1978.
6. Hook, J. E. and L. T. Kardos. Nitrate Relationships in the Pennsylvania
State "Living Filter" System. In: Land as a Waste Management Alterna-
tive, R. C. Loehr, ed. Proceedings of the Cornell Agric. Waste Mgmt.
Conf., Ann Arbor Science Publisher, Inc., Ann Arbor, Michigan, 1976.
pp. 181-198.
7. Hook, J. E., L. T. Kardos and W. E. Sopper. Effects of Land Disposal of
Wastewaters on Soil Phosphorus Relations. In: Recycling Treated
Municipal Wastewater and Sludge Through Forest and Cropland, W. E.
Sopper and L. T. Kardos, eds. Pennsylvania State University Press,
University Park, 1973. pp. 200-219.
8. Kardos, L. T. and J. E. Hook. Phosphorus Balance in Sewage Effluent
Treated Soils. J. Env. Qual., 5(1):87-90, 1976.
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9. Kardos, L. T. and W. E. Sopper. Effect of Land Disposal of Wastewater
on Exchangeable Cations and Other Chemical Elements in the Soil. In:
Recycling Treated Municipal Wastewater and Sludge Through Forest and
Cropland, W. E. Sopper and L. T. Kardos, eds. Pennsylvania State
University Press, University Park, 1973a. pp. 220-231.
10. Kardos, L. T. and W. E. Sopper. Renovation of Municipal Wastewater
Through Land Disposal by Spray Irrigation. In: Recycling Treated
Municipal Wastewater and Sludge Through Forest and Cropland, W. E.
Sopper and L. T. Kardos, eds. Pennsylvania State University Press,
University Park, 1973b. pp. 148-163.
11. Murphy, W. K. and J. W. Bowler. The Response of Aspen to Irrigation by
Municipal Wastewater. T.A.P.P.I., 58(5):128-129, 1975.
12. Murphy, W. K. and R. L. Brisbin. Influence of Sewage Plant Effluent
Irrigation on Crown Wood and Stem Wood of Red Pine. Ag. Exper. Sta.
Bull. 772. Pennsylvania State University, University Park, 1970.
30 pp.
13. Murphy, W. K., R. L. Brisbin, W. J. Young and B. E. Cutter. Anatomical
and Physical Properties of Red Oak and Red Pine Irrigated With Municipal
Wastewater. In: Recycling Treated Municipal Wastewater and Sludge
Through Forest and Cropland, W. E. Sopper and L. T. Kardos, eds.
Pennsylvania State University Press, University Park, 1973. pp. 295-310.
14. Neary, D. G. Effects of Municipal Wastewater Irrigation on Forest Sites
in Southern Michigan. Ph.D. Thesis, Michigan State University, East
Lansing, 1974. 306 pp.
15. Neary, D. G., G. Schneider and D. P. White. Boron Toxicity in Red Pine
Following Municipal Wastewater Irrigation. Soil Sci. Soc. Amer. Proc.,
39(5):981-982, 1975.
16. Pennypacker, S. P., W. E. Sopper and L. T. Kardos. Renovation of
Wastewater Effluent by Irrigation of Forest Land. J. Water Poll. Contr.
Fed., 39(2):285-296, 1967.
17. Perkins, M. A., C. R. Goldman and R. L. Leonard. Residual Nutrient
Discharge in Streamwaters Influenced by Sewage Effluent Spraying.
Ecology, 56:453-460, 1975.
18. Sidle, R. C. and W. E. Sopper. Cadmium Distribution in Forest Ecosystems
Irrigated with Treated Municipal Wastewater and Sludge. J. Env. Qual.,
5(4):419-422, 1976.
19. Sopper, W. E. Disposal of Municipal Wastewater Through Forest Irriga-
tion. Environ. Pollut., 1:263-284, 1971a.
20. Sopper, W. E. Effects of Trees and Forests in Neutralizing Waste. In:
Trees and Forests in an Urbanizing Environment, University of Massachu-
setts Cooperative Extension Service Publication, 1971b. pp. 43-57.
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21. Sopper, W. E. and L. T. Kardos. Effects of Municipal Wastewater
Disposal on the Forest Ecosystem. J. Forestry, 70(9):540-545, 1972.
22. Sopper, W. E. and L. T. Kardos. Vegetation Responses to Irrigation With
Treated Municipal Wastewater. In: Recycling Treated Municipal Waste-
water and Sludge Through Forest and Cropland, W. E. Sopper and L. T.
Kardos, eds. Pennsylvania State University Press, University Park, 1973.
pp. 271-294.
23. Urie, D. H. Phosphorus and Nitrate Levels in Groundwater as Related to
Irrigation of Jack Pine with Sewage Effluent. In: Recycling Treated
Municipal Wastewater and Sludge Through Forest and Cropland, W.E. Sopper
and L.T. Kardos, eds. Pennsylvania State University Press, University
Park, 1973. pp. 176-183.
24. Urie, D. H. Nutrient Recycling Under Forests Treated with Sewage
Effluents and Sludge in Michigan. In: Municipal Wastewater and Sludge
Recycling on Forest Land and Disturbed Land, W. E. Sopper, ed.
Pennsylvania State University Press, University Park, 1978. (In press.)
25. Woodwell, G. M. Recycling Sewage Through Plant Communities. Amer.
Scientist, 65:556-562, 1977.
26. Woodwell, G. M., J. T. Ballard, J. Clinton and E. V. Pecan. Nutrients,
Toxins, and Water in Terrestrial and Aquatic Ecosystems Treated with
Sewage Plant Effluents. Final Report of the Upland Recharge Project.
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1978.
28. Frye, D. M. A Botanical Inventory of Sandhill Woodlot, Ingham County,
Michigan. I. The Vegetation. Mich. Bot., 15:131-140, 1976.
29. Frye, D. M. A Botanical Inventory of Sandhill Woodlot, Ingham County,
Michigan. II. Checklist of Vascular Plants. Mich. Bot., 15:195-204,
1976.
30. Zobeck, T. M. The Characterization and Interpretation of a Complex Soil
Landscape in South-Central Michigan. M.S. Thesis, Michigan State
University, East Lansing, 1976. 121 pp.
31. Thornthwaite, D. W. and J. R. Mather. Instructions and Tables for
Computing Potential Evapotranspiration and the Water Balance. Pubs, in
Climatology, Vol. 10. Laboratory of Climatology, Drexel Institute of
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32. U.S. Environmental Protection Agency. Methods of Chemical Analysis of
Water and Wastes. EPA-625/16-74-003, U.S. Environmental Protection
Agency, 1974.
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33. Black, C.A. (ed.)- Methods of Soil Analysis; Part 2 Chemical and
Microbiological Properties. Agronomy Monogr. 9, Am. Soc. Agron.,
Madison, Wisconsin, 1965. 1572 pp.
34. Likens, G.E., F.H. Bormann, R.S. Pierce, J.S. Eaton, and N.M. Johnson.
Biogeochemistry of a Forested Ecosystem. Springer-Verlag, New York,
New York, 1977. 146 pp.
35. Richardson, C.J. and J.A. Lund. Effects of Clear-cutting on Nutrient
Losses in Aspen Forests on Three Soil Types in Michigan. In: Mineral
Cycling in Southeastern Ecosystems, F.G. Howell, J.B. Gentry, and
M.H. Smith, eds. U.S. ERDA Symposium Series, CONF-740513, 1975.
pp. 673-686.
36. Tamm, C.D., H. Holmen, B. Popovic, and G. Wiklander. Leaching of
Plant Nutrients from Soils as a Consequence of Forestry Operations.
Ambio, 6(3):211-221, 1974.
37. Timmons, D.R., E.S. Verry, R.E. Burwell, and R.F. Holt. Nutrient
Transport in Surface Runoff and Interflow from an Aspen-Birch Forest.
J. Env. Qual., 6(2):188-192, 1977.
38. Vitousek, P.M. The Regulation of Element Concentrations in Mountain
Streams in the Northeastern United States. Ecol. Monoer., 47(1):65-
87, 1977.
39. Wells, C.G., A.K. Nicholas, and S.W. Buol. Some Effects'of Fertiliza-
tion on Mineral Cycling in Loblolly Pine. In: Mineral Cycling in
Southeastern Ecosystems, F.G. Howell, J.B. Gentry, and M.H. Smith,
eds. U.S. ERDA Symposium Series, CONF-740513, 1975. pp. 754-764.
40. Harmsen, G.W. and D.A. Van Schreven. Mineralization of Organic Nitro-
gen in Soil. In: Advances in Agronomy, Vol. 7, A.G. Norman, ed.
Academic Press, New York, 1955. pp. 299-398.
41. Hoeft, R.G., D.R. Keeney, and L.M. Walsh. Nitrogen and Sulfur in Pre-
cipitation and Sulfur Dioxide in the Atmosphere in Wisconsin. J. Env.
Qual., 1(2):203-208, 1972.
42. King, D.L. and T.G. Bahr. Wastewater Recycling: Coupling Aquatic
and Land Irrigation Systems. In: Proceedings of Specialty Conference
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Eng., New York, 1976. pp. 128-137.
120
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SECTION 8
WINTER SPRAY IRRIGATION OF SECONDARY MUNICIPAL EFFLUENT IN MICHIGAN*
David E. Leland, David C. Wiggert, and Thomas M. Burton
INTRODUCTION
Eutrophication of surface waters in the United States has resulted
in the establishment of stringent standards for point source nitrogen and
phosphorus discharges. Secondary municipal wastewater treatment plants are
major point sources and a number of physical, chemical, and biological ter-
tiary treatment methods have been devised to enable plants to meet the new
standards. Land application of sewage plant effluents has received consid-
erable attention because of low energy requirements and potential for re-
cycling nutrients and water. In northern climates where the growing season
is of limited duration, land application during the winter months would
result in savings in both land and lagoon storage and would add flexibility
in management of land application systems. However, soil microorganism
and plant activities which take up significant quantities of nitrogen and
123
phosphorus from sewage effluents applied to the land ' ' are reduced to
negligible levels under cold winter conditions.
Data currently available on land application of sewage effluents
during the winter in northern climates are insufficient for establishment
of design and operating criteria for such systems. Studies conducted at
Pennsylvania State University4 and at the U.S. Army's Cold Region Research
and Engineering Laboratory in New Hampshire indicated that winter irriga-
tion could be accomplished with excellent phosphorus removal. However, in
the New Hampshire studies nitrogen was stored in the soil over the winter
and was released in a large pulse after the soil warmed in the spring.
* This section has been accepted for publication in the Journal Water
Pollution Control Federation.
121
-------
Nitrogen application in the New Hampshire studies was primarily in the
ammonium ion form which will sorb to soil particles. Nitrification appar-
ently occurred when the soil warmed resulting in a large, pulsed loss of
nitrogen as nitrate and would have resulted in groundwater contamination in
an operating system. Runoff nutrient concentrations were minimum when soil
percolation occurred in the Pennsylvania State system and maximum under
frozen soil conditions. Thus, soil frost penetration would require such
systems to limit operation. Techniques need to be developed which will
limit frost penetration and maintain soil infiltration and percolation.
Also, further studies need to be conducted under the varied climatic con-
ditions that occur in northern climates.
Water quality standards must be met even during winter operations.
Regulations pursuant to Michigan Public Act 245 call for 80% phosphorus
concentration reduction in surface discharge or a maximum monthly concen-
tration of 1.0 mg P/£. Groundwater supplies must be protected from nitrate
contamination; therefore, the standard of 10 mg N/£ nitrate as called for
in the National Interim Primary Drinking Water Regulations should not be
exceeded in the groundwater at the spray site.
A year round spray irrigation study was conducted from December, 1975,
to March, 1977, on a 3 ha unmodified oldfield subwatershed in southern
Michigan using secondary municipal effluent from the city of East Lansing,
Michigan. The purpose of this study was to provide the data base necessary
for establishment of design and operating criteria for winter spray irri-
gation of secondary sewage effluents. Seasonal mass balances were construc-
ted for nitrogen, phosphorus, chloride, and water, and were used to compare
winter wastewater renovation efficiencies with efficiencies achieved during
active growing seasons. Mass balances for the entire study period are dis-
cussed in this paper. The winter 1976-77 data are emphasized since these
represent data collected after the newly constructed East Lansing waste-
water treatment facility went on-line and are indicative of routine opera-
tion using secondary effluent.
DESCRIPTION OF THE STUDY AREA
This study was conducted on a 3 ha oldfield subwatershed on the Water
Quality Management Project (WQMP) spray irrigation facility located on the
122
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Michigan State University campus. The WQMP is operated by the Institute of
Water Research at Michigan State and consists of a series of four man-made
1.8 m deep lakes with a total surface area of 16.2 ha and a 58 ha land irri-
gation site. During the 1976 growing season, the lakes received 1890 m /
day (0.5 MGD) of unchlorinated secondary effluent from the East Lansing
O
sewage treatment plant. An additional 1100 to 1500 m /day of secondary
effluent were received, chlorinated and spray irrigated on several specific
research projects on the WQMP irrigation site. During the winter of 1975-
1976, the new East Lansing sewage treatment plant had not been completed.
Wastewater from the old, overloaded plant was used to fill the four lakes
with wastewater effluent which had undergone phosphorus removal. Winter
irrigation was from the first lake in the series and represented stored
tertiary wastewater. Thus, the 1975-76 winter data do not represent load-
ings typical of secondary effluent. The WQMP started receiving secondary
effluent with no phosphorus removal from the section of the East Lansing
plant associated with the WQMP in April, 1976. All irrigation of the win-
ter spray area from that time has been with chlorinated secondary effluent.
The 3 ha area selected for study represents a discrete subwatershed
unit with well defined surface topography and is shown in Figure 8-1. An
intensive soil survey of this site in 1976 showed that 70% of the site
consists of Miami-Marlette soil, a loam, silt loam or silt glacial till
while the remainder of the site consists of sand, sandy clay loam and clay
loam soil. Extreme variation of soil type exists both laterally and verti-
cally with numerous sand and clay lenses.
Vegetation on this old abandoned field is dominated by goldenrod
(Solidago canadensis and Solidago graminifolia) and quackgrass (Agropyron
repens) but consists of more than 15 species of grasses and herbs. Vege-
tation biomass on the irrigated field peaked at 7880 kg/ha in mid-August
in 1976.
GENERAL METHODS
Seasonal mass balances for water, chloride, nitrogen, and phosphorus
were constructed. Such mass balances required hydrologic and water quality
data on spray and precipitation input, surface runoff, infiltration, and
123
-------
to
D
A
&
•
O
LYSIMETERS- 0.5, 1.0, 1.5 m DEPTHS
LYSIMETERS- 1.0, 1.5 m DEPTHS
LYSIMETERS- 1.5m DEPTH ONLY
OBSERVATION WELL AND ELEVATION
SPRAY SAMPLING STATION
N
m
FELTON DRAIN
MAIN DRAIN PIPE
UPPER DRAIN PIP
ACCESS ROAD
EARTHEN DIKE
EXCAVATED CHANNEL
WEIR, STAGE RECORDER,
I SCO SAMPLER
WATERSHED BOUNDARY-
SPRAY IRRIGATION LINES
*876.3
Figure 8-1: Detail map of winter spray site.
-------
evapotranspiration. Equipment locations are shown in Figure 8-1. Spray
input volume was determined from WQMP pumping records and water quality sam-
ples of spray were collected at various locations in the field. Precipita-
tion input was measured with a Bendix recording rain gauge located near the
site. Precipitation quality was not measured; previously published values
for mid-western locations were used: 0.027 mg P/d total phosphorus, 0.35 mg
7 8
Cl/A chloride, 2.67 mg N/£ nitrate, 0.25 mg N/£ ammonia. ' Surface runoff
was conducted to Felton Drain by the excavated channel shown in Figure 8-1.
Streamflow data and water quality samples were collected as shown in Figure
8-2. An ISCO model 1392 sequential sampler was used to accomplish detailed
automatic surface runoff sampling. Samples of infiltrated water were col-
lected in porous cup suction lysimeters at several depths in various loca-
tions around the spray site and the depth to the groundwater table was
measured in shallow observation wells at locations shown in Figure 8-1.
Evapotranspiration was estimated using the empirical method proposed by
Thornthwaite which employs easily obtainable local weather data.
Research at the Pennsylvania State University established that 5 cm
(2 inches) per week was a safe secondary effluent application rate for
perennial grasses.2 In the current study 2.5 cm (1 inch) of wastewater was
applied to the site twice per week at the rate of 0.84 cm/hr using Buckner
8600 agricultural spray heads spaced at 27.4 m (90 feet) intervals. No
wastewater was applied during periods of surface runoff.
Water quality determinations were performed by the Institute of Water
Research Water Quality Laboratory. The following analyses were performed
according to U.S. Environmental Protection Agency approved autoanalyzer
methods10: automated chloride method (Storet 00940), automated colorime-
tric phenate ammonia nitrogen method (Storet 00610), nitrite nitrogen
(Storet 00615), automated cadmium reduction nitrate-nitrite nitrogen method
(Storet 00630), and persulfate digestion total phosphorus method (Storet
00665) .
COMPUTATIONAL METHODS
Determination of mass balances in this experiment required calculation
of a number of input and output components. Nutrient and water inputs
125
-------
S3
STEVENS RECORDER
I SCO SAMPLER
45°V-NOTCH WEIR
SAMPLER INTAKE
PLYWOOD MOUNTING
HOUSING
INTAKE PIPE
EXCAVATED CHANNEL
Figure 8-2: Runoff monitoring station.
-------
resulted from spray and precipitation. Nutrient and water outputs included
infiltration, surface runoff, and the water and nutrient "loss" associated
with evapotranspiration, soil nutrient removal and retention processes, and
dilution in the groundwater. Data was analyzed on a seasonal basis with
seasonal periods delineated according to the hydrologic response of the
watershed.
Surface runoff data were analyzed by generating daily runoff volume
and nutrient mass totals from stage-time and water quality- time data.
Nutrient mass input from spray and precipitation volume and average quality
were caluclated in a straightforward manner. Because of difficulties en-
countered in measuring infiltration under complex soil conditions, infil-
tration volume was estimated by subtracting surface runoff and evapotrans-
piration volumes from the total water input volumes.
Nutrient reduction in the soil was calculated assuming that the dif-
ference between the input nutrient mass, or applied nutrient mass, and the
runoff nutrient mass gave the total nutrient mass infiltrating (M) . A sea-
sonal anticipated infiltrated water nutrient concentration (A) assuming no
removal of nutrient was calculated using M and the infiltration water vol-
ume estimate (I) as follows:
A, (ng/A) = -f- (1)
This ratio reflected dilution and concentration effects due to precipita-
tion and evapotranspiration. Seasonal nutrient reduction percentage in the
soil (R) was computed by comparing A to the measured average seasonal
nutrient concentration, or maximum concentration when a significant increas-
ing concentration trend was observed, measured in lysimeter samples col-
lected at the 150 cm depth (B) :
R, (%) = ^A ^ B') X 100 (2)
Reduction was assumed to include the effect of lateral inflow-outflow of
groundwater and dilution in groundwater as well as soil nutrient renovation
and retention processes. Overall nutrient reduction mass was computed as
follows :
R x M
...
Overall Reduction, (kg)
1QO
127
-------
Nutrient infiltration mass, the nutrient mass penetrating the soil to the
1.5 m depth, was obtained by difference:
Infiltration Mass, (kg) = M - Overall Reduction (4)
Negative seasonal R values were occasionally obtained for chloride
when the time lag associated with slow changes in groundwater quality re-
sulted in carry-over of high groundwater chloride levels into a season with
a lower chloride mass input. These negative R values were incorporated
into the overall mass balances for the study period but were assumed to be
zero for seasonal mass balances to avoid calculation of negative seasonal
overall reductions. While this procedure introduced some numerical inac-
curacy in the seasonal data, it allowed construction of approximate sea-
sonal balances to characterize the response of the site during different
times of the year. Except when negative R values occur, it can be shown
that:
Infiltration Nutrient Mass, (kg) = B x I (5)
OVERALL RESULTS FOR STUDY PERIOD
The spray site was irrigated at a rate of 5 cm (2 inches) per week
from December 1, 1975, to March 16, 1977, except during periods of spring
runoff. Winter study periods included spring ice melt runoff events.
The overall water balance for the study period indicates that most of
the output water from the site infiltrated with the remainder divided about
equally between runoff and evapotranspiration as shown in TABLE 8-1. TABLE
8-2 lists runoff, evapotranspiration, and infiltration as a percent of
total water input by season. Minimum runoff occurred during the summer and
fall and maximum runoff occurred during the winter seasons. Infiltration
was high during all seasons but was maximum during the fall and winter.
Evapotranspiration was maximum during the summer growing season.
Overall mass balances are given in TABLE 8-3. Very small percentages
of the input nitrogen and phosphorus accompanied the surface runoff; most
of the nutrient input mass was taken up by the soil-plant system or diluted
in the groundwater. Very little infiltrated phosphorus was detected at a
depth of 1.5 m in the soil. Most of the input chloride infiltrated with
little overall reduction taking place. TABLE 8-4 gives nutrient reduction
128
-------
TABLE 8-1. OVERALL WATER BALANCE FOR STUDY PERIOD DECEMBER 1, 1975 TO
MARCH 16, 1977
Source
Input
Wastewater Spray
Precipitation
Output
Runoff
Infiltration
Evapotranspiration
3
Volume (m )
47,398
22,300
69,698
9,714
46,915
13,069
69,698
Percent of Total
68
32
100
14
67
19
100
TABLE 8-2. RUNOFF, INFILTRATION, AND EVAPOTRANSPIRATION AS PERCENT OF
TOTAL WATER INPUT BY SEASON
Season
Winter 1976
12/1/75-2/27/76
Spring 1976
2/28/76-5/27/76
Summer 1976
5/28/76-8/31/76
Fall 1976
9/1/76-11/30/76
Winter 1977
12/1/76-3/16/77
Runoff, Infiltration Evapotranspiration,
% Input % Input % Input
27 73
23 57
0 57
4 83
29 71
~0
20
43
13
~0
129
-------
TABLE 8-3. OVERALL NUTRIENT MASS BALANCES FOR STUDY PERIOD DECEMBER 1,
1975 TO MARCH 16, 1977
Nutrient
Chloride (as Cl)
Nitrate (as N)
Ammonia (as N)
Total Phosphorus
(as P)
Input
kg
spray
5,868
519
41
163
rain
8
59
6
0.6
Runoff
kg
680
24
1
6
% of
input
12
4
2
4
Overall
Reduction
kg
109
491
36
149
% of
input
2
85
77
91
Infiltration
kg
5,087
63
10
8.6
% of
input
86
11
21
5
Season
TABLE 8-4. NUTRIENT REDUCTION IN THE SOIL BY SEASON
Percent Reduction in the Soil, (R)
Chloride Ammonia Nitrate Total Phosphorus
Winter 1976
12/1/75-2/27/76
Spring 1976
2/28/76-5/27/76
Summer 1976
5/28/76-8/31/76
Fall 1976
9/1/76-11/30/76
Winter 1977
12/1/76-3/16/77
17
-54
39
-20
-28
75
60
91
66
60
93
98
99
99
68
99
98
99
99
85
130
-------
(R) in the soil by season. Reduction was high during all seasons with the
lowest values during the winter of 1977, The ammonia reduction estimate
was unreliable due to the small input mass.
Nitrogen to chloride ratios for groundwater and applied wastewater
were calculated and are given in Figure 8-3. Lake renovated effluent was
applied from January to April, 1976. Direct secondary effluent containing
higher nitrogen levels was applied from May, 1976, to February, 1977.
Nitrogen in the applied wastewater was primarily in the nitrate form and
chloride levels were fairly uniform throughout the study period. These
ratios indicate a high degree of nitrogen interception during the summer
and fall and marked breakthrough of nitrogen to the groundwater during the
winter 1977 season.
WINTER 1977 RESULTS
The winter, 1977 was a record period of severe cold weather with little
snowfall. From December 1, 1976, to February 22, 1977, 46 cm (18 inches)
of direct secondary effluent were applied to the site resulting in heavy
ice buildup. Frozen pipes and valves resulted in operational shutdown
several times; spray distribution was uneven due to spray nozzle freeze-
up. Average wastewater input nutrient concentrations were the highest of
the study period: 127 mg Cl/£ chloride, 18.4 mg N/£ nitrate, 5.6 mg P/£
total phosphorus, and 0.5 mg N/& ammonia. Nitrite concentrations were less
than 0.1 mg N/£. Spring thaw brought considerable runoff from ice melt
and rainfall during February and March, and runoff ceased on March 16
marking the end of the winter study period.
TABLE 8-5 gives the water balance for the winter period. Most of the
input water was wastewater; little precipitation was recorded. Subfreezing
temperatures resulted in an evapotranspiration estimate of zero. Field
observations revealed unfrozen conditions under the ice pack apparently
due to the ice pack insulating the soil against frost penetration; as a
result most of the output water infiltrated.
The winter nutrient mass balances are given in TABLE 8-6. The nitrite
balance was not significant due to low input levels. The lowest overall
reductions of nitrate and phosphorus observed during the study period
131
-------
U)
S3
o
0.20
0.18.
0.16.
0.14.
0.12.
0.10.
0.08-
0.06^
0.04-
0.02-
0.00.
N - AMMONIA a NITRATE (MG N/LITER)
CL- CHLORIDE (MG CL/LITER)
WASTEWATER
GROUNDWATER (1.5 M DEPTH)
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR
1976 1977
Figure 8-3: Monthly nitrogen to chloride ratios.
-------
TABLE 8-5. WATER BALANCES - WINTER 1977, DECEMBER 1, 1976 TO MARCH 16, 1977
Source
Input
Spray
Precipitation
Output
Runoff
Infiltration
Evapotranspiration
Volume
m
10,646
1,994
12,640
3,700
8,940
0
12,640
Percent of Total
84
16
100
29
71
0
100
TABLE 8-6. NUTRIENT BALANCE - WINTER 1977, DECEMBER 1, 1976 TO
MARCH 16, 1977.
Input
kg
Nutrient
Chloride (as Cl)
Nitrate (as N)
Ammonia (as N)
Total Phosphorus
(as P)
spray
1,349
196
5.5
60
rain
1
5
0.5
0.1
Runoff
kg
287
23
1.1
6
% of
Input
21
11
18
10
Overall
Reduction
kg
0
121
2.9
46.0
% of
Input
0
61
49
77
Infiltration
kg
1,063
57
2.0
8.1
% of
Input
79
28
33
13
133
-------
occurred. Higher percentages of nutrient input mass accompanied the runoff
than in previous seasons.
Figure 8-4 gives lysimeter nitrate data for the winter period. Severe
cold caused many of the lysimeter access tubes to freeze and few samples
were collected until after the thaw in March. Sufficient samples were col-
lected to show the effect of irrigation on the groundwater at the site.
Prior to saturation of the site by spring ice melt, several average nitrate
peaks greater than 10 mg N/£ were observed at the 1 meter (3 ft.) depth.
The average nitrate concentration at the 1.5 meter (5 ft.) depth reached
about 6 mg N/£ in spite of groundwater dilution.
Average daily discharge and nutrient concentrations during the spring
runoff period are shown in Figure 8-5. Initial runoff nutrient concentra-
tions were considerably higher than input levels, probably due to freeze-
out of pure water. Concentrations decreased steadily but phosphorus levels
remained above 1.0 mg P/£ during most of the runoff period.
Nutrient mass flow rates are plotted with a typical winter hydrograph
in Figure 8-6. Mass flow rates varied with discharge and peak mass flow
rates occurred with peak discharge. This behavior was also common during
other seasons.
Soil water and runoff water quality during the winter 1977 period were
the poorest of the study period. Significant nitrate buildup was observed
in the groundwater, but nitrate levels remained below 10 mg N/£ probably
due to dilution. In terms of total mass applied, 90% of the input phos-
phorus was retained on the site; however, the Michigan phosphorus discharge
standard was violated during most of the spring runoff period. Runoff vol-
ume was small allowing most of the input water to infiltrate causing
greatly increased water table elevations and saturation of most of the site.
CONCLUSIONS AND APPLICATION
From the results of this study, a number of conclusions can be drawn
concerning the impact of secondary municipal sewage effluent irrigation on
an unmodified natural watershed during northern winters. Frost penetration
into the soil was apparently prevented by beginning irrigation early in the
winter season which subsequently built up a protective ice pack. This pro-
cedure allowed significant infiltration from ice melt at the ground surface
134
-------
]
q
c\i
o:
ui
DAY 0= NOV 30, DAY 115= MAR 25
• 0.5 m Ave - Spray Zone
A 1.0 m Ave - Spray Zone
• 1.5 m Ave - Spray Zone
50 60 70
TIME (DAYS)
80
90
100 110 120
Figure 8-4: Winter 1977 lysimeter data.
-------
LJ
|
H
_J
UJ
DAY I = JANUARY 27
DISCHARGE
NITRATE
TOTAL PHOSPHORUS
10
15
20 25 30 35
TIME (DAYS)
40
45
O
> •
oo
cc
Q
CD
O
10
a:
o
10
Q
O
Figure 8-5: Average daily runoff water quality and discharge, Winter 1977.
-------
OJ
TIME 0 = 0000 HOURS,
MARCH 9, 1977
DISCHARGE
TOTAL PHOSPHORUS
NITRATE
CHLORIDE
200 400
600 800 1000
TIME (MIN)
1200 1400
o
o
o
O 2
O \
o
8 UJ
o 5
o z
00
o
Q_
C/>
O
CO X
CVlQ.
c5
Figure 8-6. Hydrograph and nutrient mass flows, March 9, 1977.
-------
to occur throughout the winter on a site which had good infiltration char-
acteristics, and runoff volume was reduced as a result. Site saturation
evident at the end of winter operations could impair spring irrigation op-
erations. Groundwater and runoff quality was poor during the winter periods
compared to the rest of the year. Nitrate accumulation accurred in the
groundwater and levels could ultimately exceed the standard of 10 mg N/£,
although they did not in this experiment. In terms of total mass applied,
effective phosphorus renovation occurred during winter operations but high
concentrations in surface runoff during the spring violated the discharge
standard of 1.0 mg P/£.
Irrigation during the winter months with low nitrogen wastewater is
an obvious solution to the nitrogen infiltration problem. This low nitro-
gen wastewater is available in the WQMP lake system in the late fall as a
result of lake mediated nitrogen stripping processes, and irrigation from
the end of the lake system could continue into the winter months while new
effluent is taken in at the head of the lake system. Winter irrigation
for phosphorus removal could proceed until the lake effluent nitrogen con-
centration reaches 10 mg N/£, effectively increasing the operating season
of the system by several months. Phosphorus retention could be enhanced
by diking or contour plowing to increase soil contact. Winter wastewater
irrigation can therefore be a potentially viable management option for
operation of a combined land-lake tertiary treatment system for nitrogen
and phosphorus renovation.
Further investigations should be carried out before this type of
system is operated on a year-round basis. The fate of bacteria and viruses
during winter operation should be determined. The wastewater employed in
this study was exclusively domestic municipal effluent, therefore the
effects of heavy metals and industrial wastes during winter operations
should be determined before these findings are extended to such systems.
138
-------
REFERENCES
1. Lance, J. Fate of Nitrogen in Sewage Effluent Applied to the Soil.
In: Proceedings of the ASCE, J. Irrigation and Drainage Div.,
101(NIR3):131-143, 1975.
2. Sopper, W. Crop Selection and Management Alternatives-Perennials.
In: Proceedings of the Joint Conference on Recycling Municipal
Sludges and Effluents on Land, Champaign, Illinois, 1973. pp. 143-
154.
3. Lance, J. Fate of Wastewater Phosphorus in the Soil. In: Proceed-
ings of the ASCE, J. Irrigation and Drainage Div., 101(NIR3):145-155,
1975.
4. Kardos, L.T, W.E. Sopper, E.A. Myers, R.R. Parizek, and J.B. Nesbitt.
Renovation of Secondary Effluent for Reuse as a Water Resource. EPA
660/2-74-016, U.S. Environmental Protection Agency, Washington, D.C.,
1974.
5. Iskander, I., R.S. Slotten, D.C. Leggert, and T.F. Jenkins. Waste-
water Renovation by a Prototype Slow Infiltration Land Treatment
System. CRREL Report 76-19, U.S. Army Corps of Engineers, Hanover,
New Hampshire, June 1976.
6. Zobeck, T. The Characterization and Interpretation of a Complex Soil
Landscape in South Central Michigan. M.S. Thesis, Michigan State
University, East Lansing, Michigan, 1976. 121 pp.
7. Murphy T., and P.V. Doskey. Inputs of Phosphorus from Precipitation
to Lake Michigan. EPA 600/3-75-605, U.S. Environmental Protection
Agency, Office of Research and Development, Environmental Research
Laboratory, Duluth, Minnesota, December 1975.
8. Carroll, D. The Encyclopedia of Geochemistry and Environmental Sci-
ences. In: Vol. IV A, R.W. Fairbridge, Ed. Van Nostrand Reinhold
Co., New York, New York, 1972, p. 1017.
9. Thornthwaite, D. and J.R. Mather. Instructions and Tables for Compu-
ting Potential Evapotranspiration and the Water Balance. Pubs, in
Climatology, Vol, 10, No. 3. Laboratory of Climatology, Drexel Insti-
tute of Technology, Centerton, New Jersey, 1957.
10. U.S. Environmental Protection Agency. Methods for Chemical Analysis
of Water and Wastes. EPA-625/6-74-003, U.S. Environmental Protection
Agency, 1974.
139
-------
SECTION 9
BASELINE OLDFIELD WATERSHED STUDIES
Thomas M. Burton and James E. Hook
INTRODUCTION
According to preliminary estimates of PLUARG, 33% of the total land
area of the Great Lakes Basin is in agricultural usage. Of this agricul-
2
tural land, approximately 56% or 103,600 km are in low intensity agricul-
tural uses such as pasture or range land. Thus, it is essential that run-
off from such low intensity land uses be quantified so that the total con-
tribution of these lands to non-point source pollution of the Great Lakes
can be estimated. An unknown but probably substantial amount of the low
intensity "agricultural" land represents marginal farm lands that have been
abandoned and are now in successional, oldfield vegetation. Runoff from
such cleared, unproductive lands should contain nitrogen and phosphorus
concentrations higher than runoff from forested lands but lower than runoff
from intensive agricultural or urban watersheds because of the residual
effect of past agricultural practices. The recent nationwide survey of
stream nutrient levels in relation to land use did include such cleared
unproductive lands but the relatively few watersheds in this survey allowed
only limited interpretation. Nutrient losses in surface runoff from
2
native prairie in west central Minnesota have been intensively studied,
but nutrient losses from successional oldfield watersheds in the Great
Lakes Basin have received little attention. Thus, a study of runoff losses
from an abandoned farm field was included as part of the Felton-Herron
Creek Pilot Watershed Study. The objective of this study was to quantify
losses of nitrogen, phosphorus, and other nutrients from abandoned farm
lands in lower Michigan.
140
-------
MATERIALS AND METHODS
An oldfield that had been abandoned approximately 18 years ago was
selected for study. The predominant vegetation on this field was goldenrod
(Solidago sp.) and quackgrass (Agropyron repens), but a very diverse flora
existed. Most of this field was included in a 7.73 ha subwatershed with
well delineated topographic boundaries on the Water Quality Management
Project's land irrigation site. Furthermore, an existing drainage tile
installed while the field was in cultivation was still functional and pro-
vided a convenient place to sample runoff from this subwatershed. The
drainage tile emptied into an artificial channel at the edge of the field.
Discharge from this channel was measured with a V-notch weir and a Stevens
Type F recorder. Water samples were taken during spring runoff and storm
events vTith an ISCO sequential water sampler. These samples were supple-
mented by low flow grab samples.
All samples were analyzed following standard techniques established
for IJC studies. Analyses included total P, molybdate reactive P, NO~-N,
N02-N, NH^-N, total Kjeldahl N (includes NH^-N), Cl, suspended solids,
sodium, and calcium.
Porous cup tube-type vacuum lysimeters were also installed at 15, 30,
60, 90, 120, and 150 cm depths at 10 sites throughout the watershed. Soil-
water samples from these lysimeters were taken weekly throughout the grow-
ing seasons of 1976 and 1977 and occasionally through the winter of 1976,
and analyzed for all forms of N, P, and Cl.
Soil samples were taken in increments to a depth of 150 cm and ana-
lyzed for Bray extractable P, NO-J-N, Cl, Ca, Mg, Na, and K in 1975 and in
1976. The 1975 samples were taken to a depth of 300 cm and were also ana-
lyzed for total P and Kjeldahl N. All analyses followed standard tech-
3
niques or modifications described in Section 5. Single soil samples were
taken at the 10 lysimeter sites in 1976. Paired soil samples were taken
in 1975 at 24 sites along a "star" shaped group of criss-crossing transects.
Precipitation inputs were monitored with three recording rain gauges
at nearby localities.
The soils have been mapped (see map in Section 4) and are predomi-
nantly loam or sandy loams. There apparently is a fairly continuous clay
141
-------
lens underlying the lower central portion of this watershed, since rela-
tively impermeable reduced clays were encountered at every soil sampling
site in the lower central part of the watershed. The existence of this
clay lens results in a perched shallow water table. As a result, samples
of soil-water were taken in these areas with suction lysimeters even after
mid-summer drought conditions when the adjacent non-irrigated forest and
oldfield areas described in Sections 5 and 7 were too dry for sampling.
RESULTS AND DISCUSSION
The water budgets for the baseline watershed indicated that little,
if any, recharge of groundwater occurred (TABLE 9-1). Almost all excess
water appears to have been intercepted by the existing tile drainage system
and exported from the watershed as runoff. The excessive runoff from this
site compared to nearby unirrigated forest and oldfield sites (Sections 5
and 7) probably resulted from the clay lens underlying the lower central
portion of this watershed as discussed earlier as well as the existing tile
drain. Tile drainage systems have been shown to be inefficient at inter-
cepting all water available for runoff or recharge in this area, at least
under irrigated conditions at a nearby site. Thus, soil-water samples
obtained at the 15 and 150 cm depths with porous cup lysimeters were useful
in characterizing storage of nutrients in the soil-water reservoir but not
as a means of characterizing water quality of groundwater leachates. Con-
sequently, most emphasis in this discussion will be on runoff of nutrients
from the site.
Soil-Water Analyses
Soil-water analyses, however, do indicate the very infertile nature
of this abandoned farm field. For example, nitrate-N increased to a yearly
high of 0.55 + .52 mg N/£, at the 15 cm depth on March 24, 1977 after the
soil began to warm, decreased rapidly to less than 0.01 mg N/£ by April 28,
1977, then increased slightly by mid-May with the weekly average varying
from 0.01 to 0.11 throughout the rest of the summer and fall. Nitrate-N
concentrations at the 150 cm depth were similar and varied from a seasonal
high of 0.30 + .16 mg N/«, on April 7, 1977 down to a low of 0.06 + .02 mg
142
-------
TABLE 9-1. WATER BUDGETS FOR THE OLDFIELD BASELINE WATERSHED
(VALUES IN m3/ha)
-
Month
October 1975
November 1975
December 1975
January 1976
February 1976
March 1976
April 1976
May 1976
June 1976
July 1976
August 1976
September 1976
ANNUAL
% of Input
October 1976
November 1976
December 1976
January 1977
February 1977
March 1977
April 1977
May 1977
June 1977
July 1977
August 1977
September 1977
ANNUAL
% of Input
Precipitation
215.9
613.0
734.1
307.3
520.7
1027.9
996.5
614.7
1112.5
657.0
135.5
394.5
7329.6
100.0
520.7
201.9
129.5
96.5
159.2
701.0
1027.9
124.5
1030.4
422.0
607.1
1148.1
6188.8
100.0
Evapotrans-
piration
315.9
244.5
0
0
0
153.8
436.8
718.2
1262.5
1187.0
695.5
534.5
5548.7
75.7
285.0
0
0
0
0
184.5
504.0
934.5
1050.4
1022.0
827.1
811.2
5618.7
90.79
Runoff
0
32.3
231.6
137.4
541.9
657.8
418.0
284.7
45.2
29.2
0
0
2378.1
32.45
0
0
0
0
21.7
108.0
323.0
14.1
0.8
0
0
0
467.6
7.56
Recharge
-100.0
336.2
502.5
169.9
-21.2
216.3
141.7
-388.2
-195.2
-559.2
-560.0
-140.0
-597.2
-8.15
235.7
201.9
129.5
96.5
137.5
408.5
200.9
-824.1
-20.8
-580.0
-220.0
336.9
102.5
1.66
in August. Weekly average concentrations varied between 0.06 and 0.13
mg N/& throughout most of the summer and fall. Spring peaks of nitrate-N
are the norm in fallow soils. Ammonia-N levels were also very low in
soil-water with weekly averages varying between 0.02 and 0.25 mg N/£ at
the 15 cm depth and between 0.05 and 0.27 mg N/£ at the 150 cm depth.
Nitrite-N was always below limits of detection (0.01 mg N/£). Weekly aver-
age organic-N concentrations varied from 0.34 to 0.93 mg N/£ at the 15 cm
depth and from 0.08 to 0.82 mg N/£ at the 150 cm depth with no obvious sea-
sonal correlation.
143
-------
Total P concentrations in soil-water were also very low with the
weekly average varying from 0.02 to 0.36 mg P/£ at the 15 cm depth and
from 0.003 to 0.32 mg P/£ at the 150 cm depth. Most weekly averages were
less than 0.080 mg P/£ at both depths. There were no obvious seasonal
trends.
Chloride concentrations were also low with weekly averages varying
from 1.4 to 8.4 mg Cl/£ with no obvious seasonal differences. There may
have been a slight increase with depth with the 150 cm depth often being
slightly higher than the 15 cm depth on any given week. The weekly average
varied between 1.8 and 7.7 mg Cl/£ for the 150 cm depth.
Runoff
Seasonal and annual runoff loadings are presented in TABLES 9-2 to
9-6. Chloride concentrations rose substantially during spring runoff
in 1977 indicating some contamination from a nearby spray irrigation pro-
ject. Also, the lysimeter site located near the runoff monitoring station
showed chloride contamination at the 150 cm depth during the spring of
1977. No other lysimeter site had chloride contamination problems, so con-
tamination affected only a small area of the baseline watershed. Neverthe-
less, loadings from only the 1975-76 water year should be used because of
this contamination problem, and no 1977 runoff data are presented (TABLES
9-2 to 9-6).
The annual flow weighted mean concentration of 0.073 mg total P/£ is
low compared t& the 0.152 mg total P/£ reported for intense agricultural
land for this region. It is intermediate between values reported for
agricultural and forest land uses as was predicted by Omernik. Orthophos-
phorus concentrations (0.028 mg P/£) also are intermediate between forest
and agricultural land uses as was predicted. However, both total and inor-
ganic nitrogen concentrations fall in the range (0.047 NO«-N, 0.078 NH.-N,
1
0.017 NCL-N) reported for forested land. Concentrations of P reported
here agree well with those estimates derived by Omernik for the eastern
region (which included the Great Lakes Basin) of the United States for land
in the 50% agriculture plus urban land use category. Total N concentrations
(0.561 mg N/£) are nearer those reported for the 0% agricultural plus urban
land use category.
144
-------
TABLE 9-2. STREAM EXPORT OF MOLYBDATE REACTIVE PHOSPHORUS AND TOTAL PHOSPHORUS FROM THE 7.73 ha
BASELINE OLDFIELD WATERSHED
Ul
Season
Fall, 1975
Winter, 1975-76
Spring Runoff 1976
Spring Post Runoff '76
Summer, 1976
Total 75-76 Water Year
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Fall, 1975
Winter, 1975-76
Spring Runoff 1976
Spring Post Runoff '76
Summer, 1976
Total 75-76 Water Year
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
TTWlTMn
Rising
Hydrograph (kg)
0.014 +
0.004 +
0.079 +
0.074 +
0.035 +
0.206 +
24
0
0
0.008 +
0.017 +
0.012 +
0.416 +
0.205 +
0.112 +
0.762 +
32
0
0
0.019 +
M 0 L Y
.0001
.0001
.002
.001
.001
.002
.88
.0001
.00004
.0002
.008
.004
.001
.009
.52
.0002
C 1
D<
H:
B
0
0
0
0
0
0
0
T
0
0
0
0
0
1
E7T HTJC
ascending
ydrograph (kg)
DATE
.059 +.
.025 +.
.204 + .
.164 + .
.051 + .
.503 + .
60.75
0
0
.083 + .
R E
001
0004
022
046
002
051
001
0 T A L P
.062 +.
.037 + .
.535 + .
.445 + .
.129 + .
.208 + .
001
0004
032
067
004
074
51.56
0
0
0
.235 + .
008
Non-Event
Flows (kg)
ACTIVE P
0.006 +
0.042 +
0.029 +
0.041 +
0.0008 +
0.119 +
14.
0
0
0.020 +
H 0 S P H
0.007 +
0.170 +
0.106 +
0.088 +
0.002 +
0.373 +
15.
0
0
0.109 +
0.000
0.398
0.065
0.283
0.001
0.493
37
0.013
0 R U
.008
.789
.203
.450
.002
.931
92
.263
Total Exports
(kg)
H 0 S P
0.079 +
0.071 +
0.312 +
0.279 +
0.087 +
0.828 +
0
0
0.111 +
S
0.086 +
0.219 +
1.057 +
0.738 +
0.243 +
2.343 +
0
0
0.363 +
H 0 R
.001
.398
.069
.287
.002
.496
.013
.008
.789
.206
.455
.005
.934
.263
% of
Total
U S
9.54
8.57
37.68
33.70
10.51
3.67
9.35
45.11
31.50
10.37
Unit
Area
Load
(kg/ha)
0.010
0.009
0.040
0.036
0.011
0.107
0
0
0.002
0.011
0.028
0.137
0.096
0.031
0.303
0
0
0.047
-------
TABLE 9-3. STREAM EXPORT OF NITRATE AND AMMONIA NITROGEN FROM THE 7.73 ha BASELINE OLDFIELD
WATERSHED
Season
Fall, 1975
Winter, 1975-76
Spring Runoff 1976
Spring Post Runoff '76
Summer, 1976
Total 75-76 Water Year
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Fall, 1975
Winter, 1975-76
Spring Runoff 1976
Spring Post Runoff '76
Summer, 1976
Total 75-76 Water Year
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Rising
Hydrograph (kg)
0.020 + .0001
0.016 + .0002
0.182 + .002
0.026 + .0004
0.018 + .0002
0.262 + .002
19.41
0
0
0.097 + .001
0.001 + .00001
0.016 + .0004
0.113 + .002
0.659 + .039
0.020 + .0002
0.809 + .039
32.74
0
0
0.009 + .0001
FT OU<3 — —
Descending
Hydrograph (kg)
NITRATE
0.095 + .001
0.023 + .0004
0.399 + .018
0.181 + .004
0.077 + .002
0.775 + .019
57.41
0
0
0.302 + .005
AMMONIA
0.011 + .0002
0.015 + .0002
0.463 + .036
0.711 + .050
0.036 + .0004
1.236 + .062
50.02
0
0
0.117 + .001
Non-Event
Flows (kg)
- N I T R 0 G
0.024 + .084
0.185 + .259
0.062 + .102
0.031 + .037
0.011 + .003
0.313 + .293
23.19
0
0
0.349 + .103
^ - N I T R 0 G
0.001 + 0.042
0.115 + 1.941
0.090 + 0.262
0.218 + 1.239
0.002 + 0.004
0.426 + 2.318
17.24
0
0
0.057 + 0.059
Total Exports
(kg)
E N
0.139 + .084
0.224 + .259
0.643 + .104
0.238 + .037
0.106 + .004
1.350 + .294
0
0
0.748 + .103
E N
0.013 + 0.042
0.146 + 1.941
0.666 + 0.264
1.588 + 1.241
0.058 + 0.004
2.471 + 2.319
0
0
0.183 + 0.059
% of
Total
10.30
16.59
47.63
17.63
7.85
0.53
5.91
26.95
64.27
2.35
___
___
TT • J_
Unit
Area
Load
(kg/ha)
0.018
0.029
0.083
0.031
0.014
0.175
0
0
0.097
0.002
0.019
0.086
0.205
0.008
0.320
0
0
0.024
-------
TABLE 9-4. STREAM EXPORT OF NITRITE AND TOTAL KJELDAHL NITROGEN FROM THE 7.73 ha BASELINE
OLDFIELD WATERSHED
Season
Fall, 1975
Winter, 1975-76
Spring Runoff 1976
Spring Post Runoff '76
Summer, 1976
Total 75-76 Water Year*
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Fall, 1975
Winter, 1975-76
Spring Runoff 1976
Spring Post Runoff '76
Summer, 1976
Total 75-76 Water Year*
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff 1977
Rising
Hydrograp
ND#
0.001 + .
0.021 + .
0.084 + .
0.004 + .
0.110 + .
27.99
0
0
0.006 + .
0.122 + .
0.069 + .
1.589 + .
1.334 + .
0.362 + .
3.476 + .
EVENT
h (kg)
00002
0003
003
00004
003
i T?T AT.TC
Descending
Hydrograph (kg)
N I
ND
0.004 +
0.176 +
0.054 +
0.004 +
0.238 +
TRITE
Non-Event
Flows (kg)
-NIT
Total Exports
(kg)
% of
Total
Unit
Area
Load
(kg/ha)
R 0 G E N
ND
0.0001
0.033
0.005
0.000
0.033
0
0
0
0
0
60.56
0001
0004
001
037
021
003
043
21.41
0
0
0.144 + .
001
0
0
0.021 +
T 0 T A
0.420 +
0.083 +
3.863 +
4.949 +
0.672 +
9.987 +
0.001
L K
.002
.001
.123
.717
.003
.728
0
J
0
0
0
0
0
2
61.52
0
0
1.269 +
.036
0
.015 + 0.
.019 + 0.
.011 + 0.
.0004+ 0.
.045 + 0.
11.45
0
0
.013 + 0.
033
030
019
000
048
Oil
E L D A H L -
.081 + 0.
.835 + 4.
.961 + 1.
.846 + 1.
.048 + 0.
.771 + 4.
17.07
0
0
.936 + 0.
418
457
078
153
005
747
425
ND
0.020 +
0.216 +
0.149 +
0.008 +
0.393 +
0
0
0.040 +
N I T R 0
0.623 +
0.987 +
6.413 +
7.129 +
1.082 +
16.234 +
0
0
2.349 +
.033
.045
.020
.00004
.059
.011
GEN
0.418
4.457
1.086
1.358
0.006
4.802
0.427
A
5.09
54.96
37.91
2.04
0
0
3.84
6.08
39.50
43.91
6.67
0
0
ND
0.003
0.028
0.019
0.001
0.051
0
0
0.005
0.081
0.128
0.830
0.922
0.140
2.100
0
0
0.304
ND indicates no data.
*
1975-76 water year data for NO--N were calculated using Fall, 1976, data since no Fall, 1975,
data were collected.
-------
TABLE 9-5. STREAM EXPORT OF CHLORIDE AND SUSPENDED SOLIDS FROM THE 7.73 ha BASELINE OLDFIELD
WATERSHED
oo
Season
Fall, 1975
Winter, 1975-76
Spring Runoff 1976
Spring Post Runoff '76
Summer, 1976 ' „
Total 75-76 Water Year
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff 1977*
Fall, 1975
Winter, 1975-76
Spring Runoff 1976
Spring Post Runoff '76
Summer, 1976
Total 75-76 Water Year//
% of Total
Fall, 1976
Winter, 1976-77
Spring Runoff 1977*
Rising
Hydrogrc
1.52 +
12.70 +
20.07 +
11.49 +
0.96 +
46.76 +
— EVEN'
iph (kg;
0.01
0.16
0.54
0.11
0.01
0.57
9.58
0
0
6.90 +
ND**
0.84 +
32.03 +
37.16 +
13.88 +
83.91 +
27.
0
0
3.08 +
0.00
0.03
0.87
3.82
0.0001
3.92
29
0.25
IT7T HTJQ
Descending
) Hydrograph (kg)
C H L 0 R I
17.78 + 0.10
17.45 + 0.08
94.06 + 3.54
80.44 + 1.45
2.40 + 0.014
212.13 + 3.83
43.44
0
0
49.99 + 0.45
SUSPEND
ND
0.75 + 0.09
31.40 + 22.39
98.08 + 44.02
27.39 + 2.15
157.62 + 49.43
51.27
0
0
13.07 + 0.95
Non-Even t
Flows (kg)
D E
6.
117.
71.
31.
1.
229.
113.
E D
ND
21.
14.
29.
0.
65.
11.
76 + 8.
58 + 254.
92 + 22.
30 + 16.
90 + 0.
46 + 256.
46.99
0
0
52 + 26.
37
41
65
00
20
05
44
SOLI
00 + 194.
24 + 34.
79 + 153.
87 + 0.
90 + 249.
21.44
0
0
90 + 16.
17
87
53
36
98
69
Total Exports % of
(kg) Total
26.
147.
186.
123.
5.
488.
170.
D S
ND
22.
77.
165.
42.
307.
28.
06 +
73 +
05 +
23 +
26 +
35 +
0
0
41 +
59 +
67 +
03 +
14 +
43 +
0
0
05 +
8.37
254.41
22.93
16.07
0.20
256.08
26.44
194.17
41.45
159.76
2.18
254.85
16.72
5.34
30.25
38.10
25.23
1.08
0
0
//
7.35
25.26
53.68
13.71
0
0
Unit
Area
Load
(kg/ha)
3.37
19.11
24.07
15.94
0.68
63.18
0
0
22.04
ND
2.92
10.05
21.35
5.45
39.77
0
0
3.63
1975-76 water year data for suspended solids were calculated using Fall, 1976 data since no Fall,
1975 data were collected.
Some Chloride contamination from an adjacent wastewater irrigation site during Spring runoff,
1977 but not at any other season.
ND indicates no data.
-------
TABLE 9-6. STREAM EXPORT OF SODIUM AND CALCIUM FROM THE 7.73 ha BASELINE OLDFIELD WATERSHED
Season
Rising
Hydrogra
— EVENT
iph (kg)
FLOW
Desc
Hydr
'C
ending Non-Event
ograph (kg) Flows (kg)
Total Exports
(kg)
% of
Total
Unit
Area
Load
(kg/ha)
SODIUM
Fall, 1975
Winter, 1975-76
Spring Runoff 1976
Spring Post Runoff '76
Summer, 1976
Total 75-76 Water Year
% of Total
Fall, 1976
Winter 1976-77
Spring Runoff 1977
Fall, 1975
Winter, 1975-76
Spring Runoff 1976
Spring Post Runoff '76
Summer, 1976
Total 75-76 Water Year
% of Total
Fall, 1976
Winter 1976-77
Spring Runoff 1977
1.75 +
7.07 +
60.37 +
6.51 +
0.75 +
76.45 +
.01
.09
.47
.62
.00001
.78
17.
6.
155.
48.
1.
228.
17.36
0
0
11.94 +
11.68 +
11.02 +
78.93 +
56.24 +
13.27 +
171.14 +
.08
0.04
0.14
1.87
5.75
0.0001
6.05
18.
53.
17.
202.
236.
20.
529.
15.94
0
0
13.43 +
0.08
43.
06 +
25 +
50 +
63 +
22 +
66 +
0.38
0.17
19.94
8.87
0.05
21.83
51.94
0
0
87 +
C
18 +
02 +
51 +
09 +
87 +
67 +
49.
0
0
85 +
1.25
A L C
0.05
0.03
1.86
2.90
0.05
3.45
32
0.21
6.89 +
69.89 +
39.22 +
18.06 +
1.09 +
135.15 +
92.03
155.56
17.20
10.56
0.18
181.87
25.70 +
83.21 +
255.09 +
73.20 +
3.06 +
440.26 +
92.03
155.56
26.34
13.80
0.19
183.18
5.84
18.90
57.94
16.63
0.70
3.32
10.76
33.00
9.47
0.40
56.95
30.70
0
0
53.47 +
I U M
13.10 +
107.02 +
156.01 +
92.23 +
4.79 +
373.15 +
34.
0
0
85.52 +
16.79
8.37
86.29
35.04
30.01
1.44
98.22
75
17.91
0
0
84.28 +
77.96 +
135.06 +
437.45 +
384.56 +
38.93 +
1073.96 +
0
0
142.80 +
16.84
8.37
86.29
35.14
30.69
1.44
98.46
17.91
7.26
12.58
40.73
35.81
3.62
0
0
10.90
10.09
17.47
56.59
49.75
5.04
138.93
0
0
18.47
-------
It is not surprising that nitrogen concentrations in runoff are so low
from this abandoned farm field since nitrogen is normally one of the pri-
mary limiting factors to terrestrial plant productivity. Inorganic N also
is readily immobilized by plant uptake, and buildup in the organic content
of soils in uncultivated fields or is rapidly lost by leaching to the ground-
water. In addition, nitrogen application rates were much lower in the
late 1950's when this field was abandoned. Thus, any residual inorganic
N would have long since been immobilized in the plant biomass, soil organic
matter, or soil microbial community or would have been leached to ground-
water. Conversely, total P concentrations would still be expected to be
elevated because of greater suspended solids loads (TABLE 9-5) carried by
the still functional drainage tile and the greater erodibility of oldfields
compared to undisturbed forests.
The excellent agreement between results from this study and the nation-
wide survey are encouraging. The loadings from this study (TABLES 9-2 to
9-6) can be extrapolated with some confidence to runoff from abandoned
farm lands throughout the Great Lakes Basin.
Soil Analyses
Soil analyses from 1975 and 1976 also indicated the very low fertility
of this abandoned farm land (TABLES 9-7,9-8). Both available (Bray extract-
able) phosphorus and nitrate were very low in these soils (TABLE 9-7).
Both elements tended to decrease with depth with highest concentrations in
the top 15 cm of soil where much of the root biomass and soil organic mat-
ter was located. The trend of decreased concentration with depth was much
more apparent in 1975 than in 1976. Total kjeldahl N also followed the
trend of decreases with depth with kjeldahl N being more than an order
of magnitude greater in the highly organic surface soils (1095 yg/g dry
soil in the top 5 cm) than at the 150 cm depth (68 yg/g dry soil). Anal-
yses down to 300 cm were included in the 1975 sampling program; kjeldahl
N continued to decrease to 34 yg/g dry soil at the 300 cm depth. Total P
concentrations were also higher in the surface soils (342 + 204 yg/g dry
soil in the top 5 cm), decreased rapidly to 254 + 221 yg/g dry soil in the
31-45 cm increment, then leveled off at a concentration of about 250 yg/g
150
-------
TABLE 9-7. PHOSPHORUS, NITROGEN, AND CHLORIDE ANALYSES OF SOILS FROM THE BASELINE WATERSHED
(VALUES IN yg/g DRY SOIL)
Bray
Depth Extractable P
(cm)
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
1975
4.6
2.5
2.9
2.4
2.6
2.3
2.6
2.2
1.9
1.3
2.5
Bray
Extractable P
1976
5.6
5.0
5.1
4.9
4.9
6.0
4.8
3.8
3.5
3.0
4.7
Total P*
1975
336
283
254
245
252
282
277
283
236
231
268
N03-N
1975
3.8
3.0
2.0
1.8
1.8
1.8
1.8
1.8
1.6
1.6
2.1
N03-N
1976
4.8
4.1
3.8
3.8
3.5
3.4
4.4
3.8
3.3
3.3
3.8
Kjeldahl N*
1975
955
599
379
247
222
178
134
102
81
68
297
Chloride
1975
8.7
4.4
4.2
3.8
4.0
4.3
4.2
4.1
4.0
4.1
4.6
Chloride
1976
18.1
15.4
15.0
15.9
17.2
14.7
15.6
16.6
16.6
15.9
16.1
No 1976 data.
TABLE 9-8. MAJOR EXCHANGEABLE CATION ANALYSES FOR 1976 FOR THE BASELINE WATERSHED SOILS
(VALUES IN yg/g DRY SOIL)
Depth (cm)
0- 15
15- 30
30- 45
45- 60
60- 75
75- 90
90-105
105-120
120-135
135-150
AVERAGE
Calcium
1612
1493
1630
1760
1231
1839
1967
2254
2309
2649
1874
Magnesium
197
191
266
316
274
237
207
215
190
159
225
Sodium
48
49
48
54
53
62
66
60
58
68
56
Potassium
67
57
75
88
67
54
61
54
58
48
63
-------
dry soil and remained at this level down to the 300 cm depth sampled in
1975.
Cation concentrations did not follow the trend of decreases with depth
(TABLE 9-8). Instead, calcium tended to increase with depth while the
other major cations showed no apparent trend (TABLE 9-8).
Chloride also followed the trend of higher concentrations in the top
15 cm of soil (TABLE 9-7), especially in 1975. Concentrations decreased
from 12.9 + 6.7 pg/g dry soil in the top 5 cm in 1975 to 5.7 + 2.5 pg/g
dry soil at the 11-15 cm increment, then leveled out at about 4 pg/g
dry soil (TABLE 9-7). Thus, part of the apparent gradient with depth
could have been the result of concentration by evapotranspiration in the
top few cm of soil. At least part of the gradient in N and P may have
been the result of interactions within the organic surface soils, but the
weaker gradient in 1976 compared to 1975 indicated that evapotranspira-
tional concentration from the surface few cm of soil was the prime mech-
anism responsible for the available P and NO--N gradients. The large dif-
ferences in kjeldahl N with depth reflected the high organic content of
surface soils, not just evapotranspirational concentration.
In summary, the soils were low in all major nutrients at all depths.
The only major significant change in any nutrient with depth was kjeldahl
N which decreased rapidly as expected from a high of 1095 pg/g dry soil
in the organic surface soils to 34 yg/g in the deep, low organic content
soils at 300 cm.
CONCLUSIONS
Abandoned farm lands are not major non-point sources of pollution.
Nitrogen loadings from such watersheds approach background levels for
undisturbed forests. Phosphorus loadings are higher and are intermediate
between loadings from undisturbed forests and intensive agricultural lands.
No remedial actions appear to be practicable or needed.
152
-------
REFERENCES
1. Omernik, J.M. Nonpoint Source — Stream Nutrient Level Relationships:
A Nationwide Study. Ecological Research Series Report, EPA-600/3-77-
105, U.S. Environmental Protection Agency, 1977. 151 pp.
2. Timmons, D.R. and R.F. Holt. Nutrient Losses in Surface Runoff From
a Native Prairie. J. Env. Qual., 6(4):369-373, 1977.
3. Black, C.A. (ed.). Methods of Soil Analysis; Part 2, Chemical and
Microbiological Properties. Agronomy Monogr. 9, Am. Soc. Agron.,
Madison, Wisconsin, 1965. 1572 pp.
4. Karlen, D.L., M.L. Vitosh, and R.J. Kunze. Irrigation of Corn with
Simulated Municipal Sewage Effluent. J. Env. Qual., 5(3):269-273,
1976.
5. Harmsen, G.W. and D.A. Van Schreven. Mineralization of Organic Nitro-
gen in Soil. In: Advances in Agronomy, Vol. 7, A.G. Norman, ed.
Academic Press, New York, 1955. pp. 299-398.
153
-------
SECTION 10
INTRODUCTION TO MILL CREEK STUDIES
A study of Mill Creek, a subwatershed of the Grand River basin was
begun in 1974 as part of the Task C Pilot Watershed Studies of PLUARG.
Mill Creek represents a watershed typical of the large fruit growing region
of southwestern lower Michigan. Since fruit orchard farming utilizes some
of the most intensive pesticide application rates of any agricultural prac-
tices in the Great Lakes Basin, it seemed particularly appropriate at the
initiation of these studies to emphasize pesticide transport processes.
Studies of nutrient exports were also included but not emphasized.
The pesticide transport process can be divided into two categories:
(1) pesticide transported in solution, and (2) pesticide adsorbed to par-
ticulate matter and convected along with the sediment load of the stream.
This distinction is necessary if one is to accurately identify the source
of the problem.
The removal and subsequent transport of agricultural non-point source
pollutants are directly related to the rainfall-runoff process. Overland
flow is responsible for the initial movement of pollutants from the land
surface to the stream. Once in the stream, the pollutant may be transpor-
ted considerable distances by the stream flow. In the particular case of
pesticides the quantity transported is related to the solubility and adsorp-
tive characteristics of the pesticide considered. The translocation of
pesticides that are adsorbed to or coated on sediment particles depends on
the many variables influencing the capability of a stream to transport sed-
iment, whereas those that are water soluble will be convected in amounts
that are directly proportional to their concentration level and the stream
discharge.
In view of the above description of the processes responsible for the
transport of pesticides, the major objective of our research effort was to
154
-------
determine the relative amount of pesticide transported on the suspended
solids and in solution. As a result of such a determination it would then
be possible to ascertain the magnitude and source of this non-point source
problem.
DESCRIPTION OF THE STUDY AREA
The Mill Creek watershed is located in midwestern lower Michigan. It
includes Cranberry Lake and watershed. Mill Creek originates from
Cranberry Lake at the Ottawa-Kent County line and flows southeasterly
through Kent County, joining the Grand River at Comstock Park. Three
major tributaries enter the creek (Figure 10-1). Upstream, the land is
rolling with orchards and grain predominating. Proceeding downstream the
creek goes from agricultural to urban development. In general the stream
may be described as a cold water, usually clear creek with a drainage
system representative of a midwestern agricultural and urban creek of
moderate size and low relief gradient.
Initially, sampling of pesticides, sediments, and nutrients were con-
ducted at nine stations established from Cranberry Lake to the creek's
mouth as it enters the Grand River. Comprehensive analyses of some 57
pesticide parameters allowed the identification of problem pesticides and
then concentration of efforts on the transport processes responsible for
movement of these problem pesticides within and from the creek. After the
initial survey of the entire watershed, studies were concentrated on the
agricultural portion of the watershed upstream of station 5 at M-37 (Figure
10-1). Downstream of M-37, the watershed becomes urbanized with housing
subdivisions, light industry, and a golf course — land uses not indicative
of the problem under investigation.
Land use in the 3058 ha watershed upstream of station 5 (Figure 10-1)
is almost completely agricultural with about 90% of the area in cultivation
and the other 10% in woodlots or wetlands. About 50% of the watershed is
in corn, 30% in fruit orchards predominated by apples but with some cherries
and other fruits, and the remaining 10% in pasture or alfalfa.
Almost 90% of the soils are loams or loamy sands (TABLE 10-1) of
glacial origin. In general, the higher elevation soils are almost exclu-
sively loam with Nester, Marlette, and Capac being the three predominant
155
-------
Ui
0
O Recording Rain Gage
A Recording Stream Gage
1 2
-1 ' Kilometers
SCALE
Figure 10-1. Mill Creek watershed.
-------
TABLE 10-1: MAJOR SOILS OF THE 3058 ha MILL CREEK WATERSHED
Soil
Area (ha) Percent of Total
Loam 2,242 73.3
Loamy Sand 489 16-0
Muck 153 5.0
Sandy Loam 99 3.2
Alluvial Land 30 1-0
Fine Sandy Loam 6 0.2
Fine Sand 4 °-1
(Lakes) 35 1.1
soil types. In the areas adjacent to the streams, the soils are almost all
loamy sands predominately of the Spinks, Brady, Oshtemo, and Chelsea series
interspersed with pockets of muck, sandy loam, fine sandy loam and other
alluvial lands (TABLE 10-1). Slopes are generally in the 2 to 12% range
with some ridges in the 12-18% range.
Locations of major sampling stations are shown in Figure 10-1. There
were three subwatersheds sampled with automatic (ISCO) sequential storm-
water samplers so that loadings of major pesticides, sediments, and nutri-
ents could be calculated. These three stations include (1) the 889 ha
North Branch watershed (station 7, Figure 10-1), (2) the 1146 ha upper
Mill Creek watershed prior to its confluence with North Branch (station 8,
Figure 10-1), and (3) the entire 3058 ha agricultural portion of Mill
Creek upstream of the urban area (station 5, Figure 10-1). Precipitation
on the watershed was monitored with three recording rain gauges (Figure
10-1).
Detailed descriptions and discussions of the methods, results and
discussion, and conclusions from studies of nutrient export, suspended
sediment movement, and pesticide transport processes and exports will be
presented in Sections 11, 12, and 13.
157
-------
SECTION 11
NUTRIENT EXPORTS FROM THE MILL CREEK WATERSHED
T.M. Burton and C.S. Annett
INTRODUCTION
The Mill Creek Watershed Study had as its basic objective the quanti-
fication of pesticide exports from a "typical" watershed in the fruit
growing region of southwestern lower Michigan. Nevertheless, some studies
of nutrient export were included since nutrient export from fruit growing
regions within the Great Lakes Basin have not been characterized very well.
While these studies were limited, enough data were collected to broadly
characterize the nutrient export from such watersheds. This section is a
report on these limited nutrient export studies.
MATERIALS AND METHODS
The general description of the Mill Creek Watershed Study has already
been given (Section 10). The sampling procedure consisted of taking
aliquots of water from the pesticide-suspended sediment samples collected
by an automatic pump sampler (ISCO, Model 1392). The sampler was turned
on by a rise in stream level by an automatic device. The sampler then
took 28 separate samples over a 48 hour period. Each separate sample
actually consisted of eight subsamples pumped into a 3.8 £ glass jug at
12.38 minute intervals. Thus, each sample represented a 1.7 hour "compos-
ite" sample of stream water. These automatic pump samples were taken at
stations 5, 7, and 8 (Figure 10-1) and were supplemented by grab samples
taken during maintenance trips to the watershed (see Sections 12 and 13
for a more detailed description of the sampling protocol). Because first
priority of analyses was placed on pesticide and suspended sediment
analyses, only a limited number of nutrient samples were analyzed. There
158
-------
were enough runoff event samples to characterize the export of nutrients
during the limited number of runoff events that occurred during the two
years of this study (1975-76 and 1976-77). However, low flow sampling was
very limited and the very large errors associated with estimates of export
during non-runoff events resulted in fairly large mean error terms for
annual exports. Nevertheless, the resulting data do give a "ball park"
estimate of runoff from this type of mixed fruit orchard-corn land use
within the Great Lakes Basin.
All analytical methods followed the techniques agreed upon by the
International Joint Commission (IJC). Basically, all techniques followed
1 2
standard auto-analyzer techniques or Standard Methods. Inter-Laboratory
comparisons showed that our analytical techniques were comparable to those
used by other laboratories associated with the Pilot Watershed Studies of
IJC.
RESULTS AND DISCUSSION
Enough samples were taken at station 5 (Figure 10-1) to enable us to
calculate annual loading using both event and non-event strata (TABLE 11-1).
The events were sampled often enough that good estimates of exports on the
rising and falling limb of the hydrograph could be calculated (TABLE 11-1).
However only a few non-event samples were taken. Thus, mean errors asso-
ciated with non-event estimates in both water years are often equal to or
greater than the mean value. This large non-event error term results in a
fairly large error term associated with the annual estimate as well. This
large error term results to a great degree from the method of calculation.
Well over 50% of most constituents are exported in runoff events where the
error is very small. Thus, the annual export figure is in the right "ball
park" at least and is probably a much better estimate than the error term
would indicate. For this particular case, using the unbiased flow weighted
mean concentration times the mean annual flow (no within year strati-
3
fication), as was done for the summary pilot watershed report, results in
lower error terms for some of the constituents. The two different esti-
mates are reasonably close for all constituents (TABLE 11-2). In parti-
cular, the phosphorus and nitrogen estimates are very close using the two
159
-------
TABLE 11-1: NUTRIENT EXPORTS FROM THE 3058 ha MILL CREEK WATERSHED
TTVTTNT PT OTJQ
Rising Descending
Hydrograph (kg) Hydrograph (kg)
1975-1976
Unit
Area
Non-Event Loads
Flows (kg) Total Exports (kg) (kg/ha)
WATER YEAR
Total Phosphorus
Ortho Phosphorus
Nitrate-Nitrogen
Nitrite-Nitrogen
Ammonia-Nitrogen
Kj eldahl-Nitrogen
Chloride
Calcium
Sodium
130.62 + 0.01
17.41 + 0.003
833 + 0.1
26.65 + 0.003
32.6 + 0.004
524 + 0.1
10,756 + 2
51,460 + 9
5,185 + 1
943.28 + 0.84
657.18 + 0
12,418 + 6
97.31 + 0.02
1,261.0 + 0.01
6,780 + 3
34,214 + 9
510,891 + 358
48,249 + 41
676.56 + 1,714
392.30 + 976.01
8,287 + 714
107.16 + 0.00001
287.8 + 119
4,354 + 238
114,135 + 196,392
448,175 + 26,186
50,552 + 2,619
1,750 + 1,714 0.57
1,067 + 976 0.35
21,538 + 714 7.04
231 + 0.003 0.08
1,581 + 119 0.52
11,658 + 238 3.81
159,105 + 196,392 52.03
1,010,526 + 26,188 330.45
103,986 + 2,619 34.01
Total Phosphorus
Ortho Phosphorus
Nitrate-Nitrogen
Nitrite-Nitrogen
Ammonia-Nitrogen
Kj eldahl-Nitrogen
Chloride
Calcium
Sodium
246.48 + 0.09
135.78 + 0.07
3,654 + 1
9.06 + 0.004
39.7 + 0.01
930 + 0.4
22,885 + 8
99,478 + 0
10,217 + 0
1976-1977
682.65 + 18.19
353.62 + 15.75
8,096 + 93
17.54 + 0.35
25.7 + 0.3
2,323 + 53
36,114 + 24
151,020 + 735
20,104 + 105
WATER YEAR
317.00 + 1,661.37
224.73 + 295.32
3,220 + 1,429
20.88 + 0.00001
100.9 + 185.8
1,565 + 1,718
44,107 + 39,789
200,902 + 71,195
18,608 + 17,328
1,246 + 1,661 0.41
714 + 296 0.23
14,970 + 1,429 4.90
47 + 0.4 0.02
166 + 186 0.06
4,818 + 1,719 1.58
103,106 + 39,789 33.72
451,400 + 71,199 147.61
48,929 + 17,328 16.00
-------
TABLE 11-2: COMPARISON OF ANNUAL ESTIMATES FOR THE 3058 ha MILL CREEK
WATERSHED CALCULATED WITH EVENT VERSUS NON-EVENT STRATA AND
CALCULATED WITHOUT STRATIFICATION
Event Strata Used No Within Year Strata
1975-76 Total Phosphorus 1,750 +1,717 1,782 + 1,018
Ortho Phosphorus 1,067 + 976 882 + 298
Nitrate-Nitrogen 21,538+714 20,573+5,546
Nitrite-Nitrogen 231 + 0.003 288 + 285
Ammonia-Nitrogen 1,581 + 119 912 +1,023
Kjeldahl-Nitrogen 11,658+238 9,116+2,295
Chloride 159,105 + 196,392 137,303 + 23,509
Calcium 1,010,526 + 26,188 579,095 + 111,673
Sodium 103,986 + 2,619 63,901 + 8,939
1976-77 Total Phosphorus 1,246 + 1,661 1,008 + 331
Ortho Phosphorus 714 + 296 582 + 250
Nitrate-Nitrogen 14,970 + 1,429 11,786 + 3,496
Nitrite-Nitrogen 47+0.4 31+4
Ammonia-Nitrogen 166 + 186 63 + 28
Kjeldahl-Nitrogen 4,818 + 1,719 3,602 + 1,090
Chloride 103,106 + 9,789 63,863 + 8,334
Calcium 451,400 + 71,199 165,439 + 56,926
Sodium 48,929 + 17,328 19,293 + 3,644
techniques. The chloride estimate for 1975-76 and the ammonia estimate
for 1976-77 are the only two cases where less than 50% of annual export
was associated with low or non-event flow (TABLE 11-1). In both cases, the
error term with the non-event flow is very inflated and the estimate using
the no stratification technique gives a somewhat lower but comparable esti-
mate with a much lower error term. It would appear that the loadings for
this watershed do not change much regardless of computational technique and
represent reasonable approximations of annual loading from the watershed.
Total phosphorus and ortho phosphorus exports were higher than the
mean exports expected for land use with about 90% agriculture based on the
recent nationwide survey but are well within the range of total phosphorus
exports reported from other agricultural watersheds in the Great Lakes
Basin. Nitrate nitrogen exports were very near the 7.8 kg N/ha reported
in the nationwide survey in 1975-76 and somewhat lower in the drier
161
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1976-77 water year (TABLE 11-1). Thus, it would appear that this mixed
fruit orchard-corn watershed exports about the same quantity of nutrients
as do other types of agricultural watersheds in the Great Lakes Basin.
Enough data were collected at stations 7 and 8 (Figure 10-1) to calcu-
late annual loading from these stations as well. These data were computed
using a mean daily stratification technique since there was not enough data
to justify event versus non-event stratification. These data are charac-
terized by inflated error terms (TABLES 11-3 and 11-4). The non-stratifi-
o
cation technique used in the summary pilot watershed report gave lower
error terms for most constituents and probably represents more reasonable
estimates for these subwatersheds (TABLE 11-5). Both computational techni-
ques produced fairly similar estimates. These data represent fairly crude
estimates but again fall in the range expected for agricultural water-
4 5
sheds. ' Thus, the fact that 30% of this watershed is in fruit orchards
versus the more traditional corn cultivation typical of much of the midwest
has not resulted in great differences in quantity of nutrients exported
compared to other midwestern and Great Lakes watersheds.
CONCLUSIONS
The Mill Creek watershed loses about the same quantity of nutrients
per year as do other agricultural watersheds in the Great Lakes Basin.
These losses could, no doubt, be reduced somewhat by adoption of best
management practices, streambank erosion prevention techniques, etc. All
of these procedures will require long-term educational and financial com-
mitments. No short term remedial action appears appropriate.
162
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TABLE 11-3: NUTRIENT EXPORTS FROM THE 1146 ha MILL CREEK WATERSHED
ABOVE THE CONFLUENCE WITH NORTH BRANCH
Total Phosphorus
Ortho Phosphorus
Nitrate-Nitrogen
Nitrite-Nitrogen
Ammonia-Nitrogen
Kj eldahl-Nitrogen
Chloride
Calcium
Sodium
Total Phosphorus
Ortho Phosphorus
Nitrate-Nitrigen
Nitrite-Nitrogen
Ammonia-Nitrogen
Kj eldahl-Nitrogen
Chloride
Calcium
Sodium
Flow Weighted
Mean Concentration
(mg/£)
1975-76
0.099
0.037
0.958
0.040
0.039
0.569
19.436
73.769
9.640
1976-77
0.037
0.031
0.758
0.009
0.014
0.453
26.725
87.500
9.150
Total Exports (kg)
WATER YEAR
223 + 6
83.3 + 3.7
2,165 + 21
90.3 + 0
87.3 + 2.6
1,285 + 24
43,897 + 6,314
166,612 + 526
21,772 + 1,421
WATER YEAR
18 + 125
15 + 95
373 + 243
4.44 + 0
6.9 + 0
223 + 450
13,175 + 21,209
43,137 + 0
4,511 + 0
Unit
Area
Loads
(kg/ha)
0.195
0.073
1.889
0.079
0.076
1.121
38.305
145.386
18.998
0.016
0.013
0.326
0.004
0.006
0.195
11.497
37.611
3.936
163
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TABLE 11-4: NUTRIENT EXPORTS FROM THE 889 ha NORTH BRANCH SUBWATERSHED
OF MILL CREEK
Total Phosphorus
Ortho Phosphorus
Nitrate-Nitrogen
Nitrite-Nitrogen
Ammonia-Nitrogen
Kj eldahl-Nitrogen
Chloride
Calcium
Sodium
Total Phosphorus
Ortho Phosphorus
Nitrate-Nitrogen
Nitrite-Nitrogen
Ammonia-Nitrogen
Kj eldahl-Nitrogen
Chloride
Calcium
Sodium
Flow Weighted
Mean Concentration
(mg/£)
1975-76
0.105
0.057
0.963
0.013
0.090
0.745
11.552
51.275
4.460
1976-77
0.223
0.159
3.100
0.009
0.022
0.875
17.203
59.827
4.545
Total Exports (kg)
WATER YEAR
206 + 5,210
112 + 16
1,894 + 63,954
26.2 + 437.4
177.5 + 2.1
1,465 + 15,830
22,719 + 35,356
100,839 + 117,815
8,770 + 23,478
WATER YEAR
98 + 875
70 + 386
1,368 + 9,256
3.92 + .00001
9.51 + 124
386 + 914
7,590 + 20,905
26,395 + 104,981
2,005 + 9,972
Unit
Area
Loads
(kg/ha)
0.232
0.126
2.131
0.030
0.200
1.648
25.556
113.430
9.865
0.110
0.079
1.539
0.004
0.011
0.434
8.538
29.691
2.255
164
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TABLE 11-5: COMPARISON OF ANNUAL ESTIMATES COMPUTED USING MEAN DAILY
LOADINGS VERSUS ESTIMATES COMPUTED WITH NO STRATIFICATION
FOR THE NORTH BRANCH WATERSHED AND FOR THE MILL CREEK
WATERSHED ABOVE THE CONFLUENCE WITH NORTH BRANCH
Daily Strata Used
Annual Estimates
Only
NORTH BRANCH WATERSHED
1975-76 Total Phosphorus
Ortho Phosphorus
Nitrate-Nitrogen
Nitrite-Nitrogen
Ammonia-Nitrogen
Kj eldahl-Nitrogen
Chloride
Calcium
Sodium
1976-77 Total Phosphorus
Ortho Phosphorus
Nitrate-Nitrogen
Nitrite-Nitrogen
Ammonia-Nitrogen
Kj eldahl-Nitrogen
Chloride
Calcium
Sodium
1975-76 Total Phosphorus
Ortho Phosphorus
Nitrate-Nitrogen
Nitrite-Nitrogen
Ammonia-Nitrogen
Kj eldahl-Nitrogen
Chloride
Calcium
Sodium
1976-77 Total Phosphorus
Ortho Phosphorus
Nitrate-Nitrogen
Nitrite-Nitrogen
Ammonia-Nitrogen
Kj eldahl-Nitrogen
Chloride
Calcium
Sodium
206 + 5,210
112 + 16
1,894 + 63,954
26 + 437
176 + 2
1,465 + 15,830
22,719 + 33,356
100,839 + 117,815
8,770 + 23,478
98 + 875
70 + 386
1,368 + 9,256
4 + 0
10 + 124
386 + 914
7,590 + 20,905
26,395 + 104,981
2,005 + 9,972
506 + 335
217 + 99
3,529 + 1,433
113 + 137
215 + 229
2,063 + 938
40,246 + 13,602
159,078 + 42,395
19,811 + 5,105
35 + 14
32 + 13
586 + 66
6 + 11
7 + 0.3
229 + 52
19,602 + 1,169
- MILL CREEK WATERSHED ABOVE NORTH BRANCH -
223 + 6
83 + 4
2,165 + 21
90 + 0
87 + 3
1,285 + 24
43,897 + 6,314
166,612 + 526
21,772 + 1,421
18 + 125
15 + 95
373 + 243
4 + 0
7 + 0
223 + 450
13,175 + 21,209
43,137 + 0
4,511 + 0
478 + 238
216 + 105
5,200 + 2,836
44 + 41
344 + 416
2,745 + 731
33,986 + 4,377
146,055 + 25,920
13,012 + 1,605
179 + 109
113 + 43
4,061 + 2,316
7 + 2
9 + 12
851 + 301
13,954 + 2,969
31,913 + 15,662
2,757 + 1,256
165
-------
REFERENCES
1. U.S. Environmental Protection Agency. Methods for Chemical Analysis
of Water and Wastes. EPA-625/6-74-003, U.S. Environmental Protection
Agency, Office of Technology Transfer, Washington, B.C., 1974. 298 pp.
2. American Public Health Association. Standard Methods for the Exami-
nation of Water and Wastewater, 13th Edition. American Public Health
Association, Washington, D.C., 1971. 874 pp.
3. Bahr, T.G. Felton-Herron, Mill Creek Pilot Watershed Studies.
Summary Pilot Watershed Report. International Reference Group on
Great Lakes Pollution from Land Use Activities, International
Joint Commsssion, Great Lakes Regional Office, Windsor, Ontario,
Canada, 1978. 48 pp.
4. Omernik, J.M. Nonpoint Source—Stream Nutrient Level Relationships:
A Nationwide Study. EPA-600/3-77-105, U.S. Environmental Protection
Agency, Corvallis, Oregon, 1977. 151 pp.
5. CORE Group. Great Lakes Pollution from Land Use Activities, Working
Draft Document, Final Report. International Joint Commission, Great
Lakes Regional Office, Windsor, Ontario, Canada, 1978.
166
-------
SECTION 12
MILL CREEK SUSPENDED SEDIMENT STUDIES
R.E. Snow, D.A. Mclntosh, and T.M. Burton
INTRODUCTION
The importance of suspended sediments as a pollutant in streams and
as an agent of transport of nutrients, pesticides, and heavy metals is a
well recognized phenomenon. In fact, the large majority of phosphorus
o
entering a stream arises from soil erosion, as do many of the pesti-
9-10
cides. The selective nature of surface runoff with respect to removal
of fine soil particulates is very important since a large percentage of
both phosphorus and pesticides are associated with clay-sized particles or
with the small particulate organic particles that are most easily trans-
Q -I Q_l R
ported. ' These fine suspended and colloidal sized particles that
are selectively eroded to the stream are the most active in adsorption, are
readily transported by even low energy flow and are fairly stable in sus-
pension in streams. Thus, it is very important when studying runoff of
easily sorbed nutrients such as phosphorus or when studying pesticides to
include studies of suspended sediment losses from a watershed and to try
to correlate this sediment loss with pesticide and nutrient losses. An
understanding of the role of sediments in pesticide or nutrient loss is
also highly desirable as a means of predicting losses and as a means of
controlling such non-point source pollution. ' In fact, many of the best
management practices for controlling non-point source pollution from agri-
culture, urban areas, etc., emphasize control of sediment losses by such
practices as no-till farming, construction of detention basins, contour
plowing, green belts, etc.
Since quantification of pesticide losses from a "typical" fruit orchard
area of Michigan was the primary objective of the Mill Creek Watershed
167
-------
Study and since most pesticides are lost from watersheds and transported
in streams on eroded soil particles, an important secondary objective of
the Mill Creek Watershed Study was the quantification of suspended sediment
losses and an attempt to correlate these losses to pesticide exports. The
basic questions dealing with export of sediments will be included in this
section, while the suspended sediment-pesticide correlations will be dis-
cussed in the following section (Section 13).
MATERIALS AND METHODS
Suspended sediment samples were collected using two different tech-
niques at stations 5, 7, and 8 (Figure 10-1). In the first technique, an
automatic pump sampler (ISCO, Model 1392) collected samples over an entire
storm event. Sampling was initiated by a custom built device which turned
the sampler on as stream level rose. The automatic sampler was modified
to pump into a 3.8 I glass bottle. Each 3.8 £ glass bottle was filled by
pumping equal amounts at eight different periods (every 12.83 minutes)
over a 1.7 hour period with alternate samples used for pesticide or sedi-
ment analyses.
The second sampling technique involved use of a custom built, less
streamlined modification of the standard U.S. Geological Survey DH-48
18
wading rod sampler (refer to p. 152-153, Gregory and Walling ). Due to
lack of streamlining, the intake nozzle had to be extended further in
front of the bottle with the exhaust nozzle being an extended elbow nozzle.
Laboratory tests showed that these modifications overcame the lack of
streamlining and this custom-built sampler took samples comparable to those
taken with a U.S. Geological Survey DH-48 sampler. At first, samples were
taken by moving the sampler vertically through depth of the stream to
obtain depth integrated samples. However, field comparisons indicated
that several samples taken at different depths were somewhat better at
characterizing higher concentration gradients. Both techniques gave com-
parable results at lower concentrations. Thus, most hand held sampling
was done by integrated point samples. The hand held sampler also gave
19
results comparable to the ISCO sampler. More detailed information on
sampling techniques, comparability of sampling devices, etc., is available
168
-------
19
from R.E. Snow's M.S. thesis. Most data were collected from station 5
(Figure 10-1) and this data will be emphasized in the following discussion
since it represents output from the whole watershed.
Suspended sediment analyses followed the method outlined in Standard
20 19
Methods with only minor modifications. Some particle size analyses
were also conducted using a Coulter Counter Model A. The Coulter Counter
was used to obtain a rough indication of size of particles less than
100 microns in diameter. Larger particles were examined by light micro-
scope to determine an average diameter and range.
Hydrologic data were collected with Steven's Type A-71 stage-height
recorders and were converted to discharge using stage-discharge relation-
ships established by repeated measurement with current meters under a
variety of flow conditions. These data were collected for us by Paul
Bent, a retired U.S. Geological Survey hydrologist with considerable
experience at hydrologic measurements, using standard U.S. Geological
Survey procedures. Precipitation data were collected from three sites
using Bendix recording rain gauges (Figure 10-1).
RESULTS AND DISCUSSION
Suspended sediment export for the entire 3058 ha Mill Creek watershed
(station 5, Figure 10-1) was studied intensively during the 1975-76 water
19
year. The suspended sediment concentration and discharge data were used
to develop a stream discharge versus suspended sediment discharge transport
relationship (Figure 12-1). The least squares fit to these data resulted
in the following equation:
Q = 0.0078Q1'81 (1)
s
where Q is suspended sediment discharge and Q is stream discharge. Because
S
orchard watersheds have a smaller percentage of tilled land, sediment
available for transport is reduced and the coefficient in the sediment
transport equation is smaller than the coefficient of 0.05 expected for
21
a row-cropped midwestern watershed. In addition, the Mill Creek channel
has considerable foliage along the stream banks which would further reduce
the coefficient. The exponent in the equation describes the rate at which
169
-------
100.
Stream
Dlscharae
(cfs)
10.
1. 10.
Sediment Discharge (tons/day)
100.
Figure 12-1.
The suspended sediment versus stream discharge relationship
for Mill Creek at station 5 (see Figure 10-1 for station
location). This station drains the 3058 ha Mill Creek
watershed.
suspended sediment export increases with stream discharge. For large,
western watersheds, the exponent can be as high as three. Test plots in
the midwest have a relationship in which the exponent is between one and
21
two. For a small to medium-size midwestern watershed, an exponent of
1.81 seems reasonable.
The sediment yield or total sediment loss during a year was computed
with the aid of the suspended sediment transport curve as well as measure-
ments made during unsteady flow. In addition to the suspended load, the
bed load had to be estimated to obtain the total sediment yield.
o o
The method used to estimate the bed load was developed by Colby and
has been utilized by the U.S. Bureau of Reclamation. The procedure required
the mean stream velocity, stream width, mean depth, the measured mean sus-
pended sediment concentration and the concentration of the bed sediment.
The first three parameters were obtained by direct measurement or by estab-
lishing correlations between stream discharge and each parameter. For
170
-------
50
40
30
Discharge
(cfs)
20
10
9>°
.4
.6 .8
Velocity (fps)
JO
.12
Figure 12-2.
The stream discharge-stream velocity relationship for Mill
Creek at station 5 (see Figure 10-1 for station location).
This station drains the 3058 ha Mill Creek watershed.
example, the mean stream velocity was determined from the stream discharge
data using the relationship between stream discharge and velocity (Figure
12-2). Mean depth and width were also estimated from known relationships
between stream stage height and each parameter. Suspended sediment con-
centrations were measured directly or estimated from stream discharge-
suspended sediment correlations. The concentrations of bed sediment were
determined by extending the suspended sediment profile to the stream bed
and estimating the concentration.
Using direct measurements and the stream discharge-suspended sediment
transport curve (Figure 12-1), suspended sediment export for the 1975-76
water year was computed to be 663 metric tons for the whole watershed
171
-------
(TABLE 12-1) or 217 kg/ha. Bed load was computed to be 59 metric tons or
19 kg/ha. Thus, total sediment yield for this water year was 236 kg/ha or
722 metric tons for the entire watershed. The 1975-76 water year was a
period of lower than average precipitation (58 cm versus a normal 76 cm).
Thus, suspended sediment loss was probably less than normal because of
lower than normal precipitation during the last four months of the year.
This low precipitation resulted in very low sediment yields during the
last four months (Figure 12-3).
TABLE 12-1: DISCHARGE VERSUS SEDIMENT EXPORT FOR THE 3058 ha MILL CREEK
WATERSHED FOR THE 1975-76 WATER YEAR
Monthly Suspended
Mean Monthly Discharge Sediment Export
Month (£/second) (metric tons)
October, 1975
November, 1975
December , 1975
January, 1976
February, 1976
March, 1976
April, 1976
May, 1976
June, 1976
July, 1976
August, 1976
September, 1976
TOTAL
108
273
627
181
869
1339
333
352
140
86
60
55
4
36
128
6
126
302
28
27
2
1
1
2
663
Annual sediment yield from watersheds in the midwest vary from 245 kg/
21
ha to 3150 kg/ha. Mill Creek's annual sediment yield was 236 kg/ha for
1975-76, a reasonable figure considering the large percentage of orchard
farming with its associated low tillage rate, the vegetation along the
streambank, and the lower than normal precipitation for this year.
Some limited suspended sediment data were also taken along with the
pesticide analyses in 1976-77 after the end of R.E. Snow's intensive
19
study. The 1976-77 data were calculated using the Beale ratio estimator
technique and runoff event versus non-event strata for the water year.
172
-------
LU
/ERAGE MONTHLY DISCH
(LITERS/SECOND)
t— •
Ul 0
O CD
0 0
1 1
_!
0 N D J
M
M
A
300 -
co
CO
0
i
250 .
(-
LU CO
-< 0 200 _
Q h-
LU
CO O
Q £ 150 _
LU h-
Q LU
LU W
0- 100 .
CO
CO
50 _
SUSPENDED SEDIMENT LOSS
FOR OCTOBER, 1975 TO
SEPTEMBER, 1976
663 METRIC TONS
1
0 ' N ' D
F M ' A ' M ' J
J ' A
Figure 12-3. Mean monthly stream discharge and suspended sediment losses
from the 3058 ha Mill Creek watershed (station 5, Figure 10-1)
Since runoff events were emphasized in the sampling program, the non-event
stratum was characterized by an extremely large mean error term. Neverthe-
less, annual loading for the entire watershed was 750 metric tons (+ 5965)
resulting in an annual unit area loss of 245 kg/ha, a figure extremely
173
-------
close to the 217 kg/ha estimate from the more intensive study of 1975-76.
Thus, annual suspended sediment loss from the Mill Creek watershed would
appear to be on the order of 220 to 250 kg/ha during dry years such as
1975-76 and 1976-77. Losses during wetter years would be expected to be
greater, but still on the low end of losses expected from midwestern
watersheds (245 to 3150 kg/ha).21
Some crude particle size analyses were also done with the Coulter
Counter and with examination under a microscope. These analyses were done
on samples taken during the fairly low flow conditions of 110 to 180 £/sec
(Figure 12-4). The mean particle size under these conditions was about
35 microns. The intake on the Coulter Counter excluded particles greater
than 100 microns in size. Examination of 130 of these particles showed
that the mean sand sized fraction was 140 + 70 microns in size with parti-
cles as large as half a millimeter being included. Particles transported
under low flow conditions are primarily the small, fine sand and silt par-
ticles (Figure 12-4) with a few larger sand sized particles being included.
Of course, as flow increased to the large flows characteristic of spring
runoff and large storms (greater than 1000 £/sec), the size of particles
transported would increase accordingly.
CONCLUSIONS
Suspended sediment losses from the Mill Creek watershed for 1975-
76 and 1976-77 were 217 and 245 kg/ha, respectively. The calculated
bed load loss for 1975-76 was 19 kg/ha. Thus, annual sediment losses
during the course of this study were very low compared to other mid-
21
western watersheds. One of the reasons for these low losses was
probably the low streambank erosion due to considerable streambank
23
vegetation and streambank treatment by landholders. In fact,
23 24
Mildner ' estimated a total loss of sediment from streambank ero-
sion in Mill Creek as 150 metric tons per year. His estimates were
for the entire watershed, whereas our estimates were for only the
upper 58% of the watershed. If all areas were contributing equally, the
loss from the upstream area from streambank erosion would be 87 metric
tons or 12% of the 722 metric tons lost in 1975-76. This percentage is
24
about twice the 4 to 6% of total sediment yield estimated by Mildner.
174
-------
o
8-
O
<->§
UJO.
_|CO
^8.00 32.00
36.00 40.00 44.00 48.00 52.00
PRRTICLE DIRMETER (MICRONS)
56.00
60.00
15.00
20.00 25.00 30.00 35.00 40.00
PflRTICLE DIflMETER (MICRONS)
45.00
50.00
Figure 12-4.
Particle size distribution of particles less than 100 microns
in size transported during low flow periods on October 28, 1976
(flow = 110 H/sec, upper figure) and on November 28, 1976
(flow = 189 H/sec, lower figure). These size distributions
were determined with a Coulter Counter, Model A.
175
-------
A second reason for the low sediment losses was the low tillage rate asso-
ciated with orchards. A third reason was the lower than average precipita-
tion rate. Suspended sediment losses were on the low end of the range of
71
losses to be expected from midwestern watersheds.
Remedial actions needed to reduce sediment losses are minimal. Some
streambank erosion control measures could be taken, but most needed treat-
23
ment has been installed. Adoption of best management practices within
the watershed could also further reduce sediment losses to some extent.
However, sediment losses are already very low and adoption of further con-
trol measures for this watershed might not be worthwhile from an economic
standpoint.
176
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REFERENCES
1. Biggar, J.W. and R.B. Corey. Agricultural Drainage and Eutrophication.
In: Eutrophication: Causes, Consequences, Correctives. National
Academy of Sciences, Washington, D.C., 1970, pp. 404-445.
2. Holt, R.F., J.P. Johnson, and L.L. McDowell. Surface Water Quality.
In: Proceedings of the National Conservation Tillage Conference,
Soil Cons. Soc. of Am., 1973. pp. 141-156.
3. Grissinger, E.H. and L.L. McDowell. Sediment in Relation to Water
Quality. Water Resour. Bull., 6:7-14, 1970.
4. Stanford, G., C.B. England, and A.W. Taylor. Fertilizer Use and Water
Quality. ARS41-168, U.S. Department of Agriculture, Washington, D.C.,
1970. 19 pp.
5. Stewart, B.A., D.A. Woolhiser, W.H. Wischmeier, J.H. Caro, and
M.H. Frere. Control of Water Pollution from Cropland, Volume I,
A Manual for Guideline Development. EPA-600/2-75-026a, Agricultural
Research Service, U.S. Department of Agriculture and Office of
Research and Development, U.S. Environmental Protection Agency,
Washington, D.C., 1975. Ill pp.
6. Wischmeier, W.H. Cropland Erosion and Sedimentation. In: Control of
Water Pollution from Cropland, Volume II, An Overview. EPA-600/2-75-
026b, Agricultural Research Service, U.S. Department of Agriculture
and Office of Research and Development, U.S. Environmental Protection
Agency, Washington, D.C., 1976. pp. 31-57.
7. Wischmeier, W.H. and D.H. Smith. Rainfall-Erosion Losses from Crop-
land East of the Rocky Mountains. U.S.D.A. Agricultural Handbook
No. 282, U.S. Department of Agriculture, Washington, D.C., 1965.
8. Ryden, J.C., J.K. Syers, and R.F. Harris. Phosphorus in Runoff and
Streams, Advances in Agronomy, 25:1-45, 1973.
9. Barthel, W.F. Surface Hydrology and Pesticides. Pesticides and Their
Effects on Soils and Water. Special Publication No. 8, Soil Science
Society of America, 1977.
10. Sanborn, J.R. The Fate of Selected Pesticides in the Aquatic Environ-
ment. EPA-660/2-74-025, U.S. Environmental Protection Agency, 1974.
177
-------
11. Sckacht, R.A. Pesticides in the Illinois Waters of Lake Michigan.
EPA-660/3-74-002, U.S. Environmental Protection Agency, 1974.
12. Smith G.E. Losses of Fertilizers and Pesticides from Claypan Soils.
EPA-660/2-74-068, U.S. Environmental Protection Agency, 1974.
13. Shin, Y. Adsorption of DDT by Soils and Biological Materials. Ph.D.
Thesis, Michigan State University, East Lansing, Michigan, 1970.
14. Green, D.B., T.J. Logan, and N.E. Smeck. Phosphate Adsorption-
Desorption Characteristics of Suspended Sediments in the Maumee River
Basin of Ohio. J. Env. Qual., 7(2):208-212, 1978.
15. Karickhoff, S.W. and D.S. Brown. Paraquat Sorption as a Function of
Particle Size in Natural Sediments. J. Env. Qual., 7(2):246-252,
1978.
16. Donigan, A.S., Jr. and N.H. Crawford. Modeling Pesticides and Nutri-
ents on Agricultural Lands. EPA-600/2-76-043, U.S. Environmental
Protection Agency, Washington, D.C., 1976.
17. Fisher, P.O. and J.E. Siebert. Integrated Automatic Water Sample
Collection System. J. Env. Eng. Div., Proc. Am. Soc. Civil Eng.,
103(EE4):725-728, 1977.
18. Gregory, K.J. and D.E. Walling. Drainage Basin Form and Process. A
Geomorphological Approach. Halsted Press, John Wiley & Sons, New York,
New York, 1973. 456 pp.
19. Snow, R.E. Sediment and Pesticide Transport Processes Within a Small
Agricultural Watershed. M.S. Thesis, Michigan State University,
East Lansing, Michigan, 1977. 116 pp.
20. American Public Health Association. Standard Methods for the Examina-
tion of Water and Wastewater. American Public Health Association,
Washington, D.C., 1971. 874 pp.
21. American Society of Civil Engineers. Sedimentation Engineering.
Manuals and Reports on Engineering Practices, No. 54. American
Society of Civil Engineers, 1975.
22. Colby, B.R. Relationship of Unmeasured Sediment Discharge to Mean
Velocity. Trans. Am. Geophys. Union, Vol. 38, No. 5, 1957.
23. Mildner, W.F. Streambank Erosion in the United States Portion of the
Great Lakes Basin. Task C Work Group Report. International Reference
Group on Great Lakes Pollution from Land Use Activities, International
Joint Commission, Great Lakes Regional Office, Windsor, Ontario,
Canada, 1978. 45 pp.
178
-------
24 Mildner, W.F. Streambank Erosion in Mill Creek Watershed Michigan.
' Mimeo Report to International Reference Group on Great Lakes Pollution
from Land Use Activities. International Joint Commission, Great Lakes
Regional Office, Windsor, Ontario, Canada, 1976.
179
-------
SECTION 13
MILL CREEK PESTICIDE STUDIES
Matthew J. Zabik
INTRODUCTION
Mill Creek (Figure 13-1) is located in midwestern lower Michigan. It
originates in Cranberry Lake and flows southeasterly through Kent County,
joining the Grand River at Cornstock Park. Three tributaries enter the
Creek. The Creek varies in width from dried up to seven meters. Upstream
the land is rolling with orchards and grain predominating, proceeding
downstream the Creek goes from agricultural to urban development. In
general, the Creek may be described as a cold water, usually clear creek
with a drainage system representative of a midwestern agricultural and
urban creek of moderate size and low relief gradient.
Sampling Stations
Nine permanent sampling stations (Figure 13-1) were established from
Cranberry Lake to the Creek's mouth as it enters the Grand River. The
stations were primarily selected to determine pesticide input from its
tributaries and to determine any changes in pesticide content as the
Creek goes from agricultural to urban development.
Station 1 is located at the mouth of Mill Creek where it enters the
Grand River. The bottom material at this station consists of sand with a
very low percentage of organic material. The bottom is almost devoid of
any aquatic vegetation and aquatic organisms are scarce. Some of the
organisms found were gastropods representing the Mollusks, Isopods and
amphipods representing the Crustaceans, and Diptera, Hemiptera and Coleop-
tera representing the insects. At this station the Creek is approximately
six meters wide with a relatively fast flow rate.
180
-------
8i
"
85°40'
Miles
Figure 13-1.
Map of the nine permanent sampling stations established
on Mill Creek.
181
-------
Station 2 is located where York Creek crosses Lamarough Road. The
bottom consists of fine sand and silt with a moderately high percentage
of organic material. Aquatic vegetation was abundant with the Creek width
between 0.9 and 1.2 meters. The organisms found were gastropods represent-
ing the Mollusks; Odonata, Hemiptera, and Coleoptera representing the
insects; and Gasterosteidae and Cyprinidae representing Pisces. The flow
rate at this station was moderately slow. Predominate organisms were the
Gastropods which were found in abundance.
Station 3 is located at Stoney Creek Road where Strawberry Creek
crosses it. The bottom material consists of sands and stones, with silt
pockets along the banks in areas of low flow rate. Percentage of organic
material is low at this station and the Creek width varies from 2.4 to 3.1
meters with a moderate flow rate. Some of the organisms found were gastro-
pods representing the Mollusks, Isopods representing the Crustaceans,
Salientians representing Amphibians, and Hemiptera and Coleoptera repre-
senting the insects. Isopods were found in abundance at this station.
Station 4 is located where Mill Creek crosses 7 Mile Road, which
is a couple of hundred yards downstream of a golf course. At this station
the bottom material is similar to station 3 except stones are more abun-
dant. The percentage of organic material is moderately high. The flow
rate is moderately fast and the Creek width is approximately three meters.
Organisms found at this station were gastropods and pelecypods representing
the Mollusks, Decapods representing the Crustaceans, Salientians represent-
ing the Amphibians, Cyprinidae representing Pisces, and Ephemeroptera,
Trichoptera, Coleoptera, Hemiptera, Diptera representing the insects.
Station 5 is located where Mill Creek crosses M-37. Bottom material
is rocky with pockets of sand. Organic content is moderately high and
vegetation moderately abundant. The flow rate is moderately fast and the
Creek is approximately three meters wide. Pelecypods and Gastropods
represent the Mollusks and Decapods represent the Crustaceans. The insects
are represented by Diptera, Coleoptera, Ephemeroptera, and Trichoptera.
Station 6 is a cove in the northwestern corner of Baumhoff Lake.
Bottom consists of silt mixed with sand, which has been added. Aquatic
vegetation is very abundant. Organisms found here are Gastropods repre-
senting Mollusca, Amphipods representing Crustaceans, Salientians
182
-------
representing Amphibians, Hirudinea representing the Annelids, and Coleop-
tera, Hemiptera, and Odonata representing the insects.
Station 7 is located at 9 Mile Road where a Mill Creek feeder stream
crosses. Bottom material is stones and sand with beds of si.lt in areas of
low flow rate. The stream is approximately 1.5 meters in width with mod-
erate flow rate. Some of the organisms found here are pelecypods repre-
senting the Mollusks, Decapods representing the Crustaceans, Cyprinidae
and Umbridae representing Pisces, and Hemiptera, Trichoptera, Ephemeroptera,
Diptera and Coleoptera representing the insects.
Station 8 is located where Mill Creek crosses Peach Ridge Road. The
bottom material is silt and sand, containing a high percentage of organic
material. Creek flow rate at this station is approximately 1.5 meters.
The organisms found were Gastropods representing Mollusca, Umbridae repre-
senting Pisces, and Hemiptera, Coleoptera, and Odonata representing the
insects.
Station 9 is located on the north shore of Cranberry Lake. Bottom
material is sand and silt with a relatively high percentage of organic
material. No organisms were found at this station. In summer, water
turned green by large populations of algae.
METHODS
Automated Sampling
The primary focus of this effort is on the understanding of the
transport processes associated with pesticide movement from an agricul-
tural watershed and an assessment of the role of precipitation on the
transport of pesticides.
In an effort to assess the role that precipitation plays in the
release and transport of pesticides into and through the stream; the
efforts of the past two growing seasons (1975-76 and 1976-77) were to
analyze water and sediment samples taken during precipitation events.
Samples were taken every 770 seconds with eight such samples combined
to give a composite sample with a volume of 3.8 £. Twenty-eight composite
samples were taken over a 48 hour period during which a hydrologic event
occurred in Mill Creek.
183
-------
An intensive monitoring system of hydrologic variables has been in
operation on Mill Creek since August 1975. Stream discharge is continuously
recorded at gauging stations located at the State Highway M-37 crossing of
Mill Creek and on Mill Creek below the confluence with North Branch (see
Figure 10-1, stations 5, 7, and 8). Estimates of flow at other stations
are obtained by an indexing technique. Precipitation data are obtained
from three recording gauges located in such a fashion that a representative
average rainfall can be evaluated for the entire watershed. Other manual
rain gauges are utilized to supplement and check the recording gauges.
Several water quality parameters are measured at various locations on
the Mill Creek watershed, however, the parameter of concern in this study
is pesticide concentration. The monitoring of pesticides is performed at
three stations along the stream where discharge is simultaneously measured.
Pesticide concentrations are available as (1) concentration of dissolved
pesticide (5 psize and below), and (2) concentration of pesticide on sus-
pended solids (greater than 5 psize).
Auxiliary Electronic Controller for
the ISCO Water Sampler for Automated
Collection
The auxiliary electronic controller was designed specifically to
provide enhanced capabilities to ISCO Model 1392 samplers since ISCO
samplers retrofitted with these auxiliary electronic controllers can be
programmed more readily to acquire water quality samples on different parts
of anticipated hydrographs. Sampling intervals are programmable, select-
able in ten second increments from less than one minute to 2.7 hours. Two
modes of operation are possible.
Mode 1: Sampling interval is constant for all 28 samples.
Mode 2: The first 16 samples are taken at the selected
interval; subsequent samples are then taken at
double this interval.
The sampling interval is selected by three thumbwheel switches;
actual interval in seconds, is ten times the displayed value. Position of
the toggle switch sets the mode. A momentary pushbutton switch and indi-
cator light are provided for diagnostic purposes. When power is applied,
184
-------
the push-to-test switch will cause the indicator light to display the
internal clock frequency (two cycles per second).
In normal operation, sample collection is to begin when power is
applied to the ISCO sampler and installed auxiliary controller. When the
power is turned on, the sampler will initialize itself and index the fun-
nel one bottle position. The auxiliary controller allows 12 seconds to
complete the funnel indexing, then commands the sampler to collect a
sample. Samples are periodically taken from this point on at the interval
and mode set by the controls. For example, if the "sample interval select"
thumbwheel switches indicate 234, then samples will be taken at intervals
of 2430 seconds, provided the controller is in Mode 1.
Sample Storage and Handling
The methods of sampling runoff were the manual collection of indi-
vidual samples during snowmelt runoff, and the automatic and manual collec-
tion of samples during rainfall runoff. Composite samples for each pesti-
cide group were then made from the individual samples. Each individual
sample represented a certain percentage of the total flow, therefore the
volume taken from the individual sample was this percentage multiplied by
the required volume of the composite sample.
Discrete samples were held at 4 C prior to compositing. Compositing
was completed within 12 to 28 hours after sample collection. Part of the
composite sample was then frozen for later analysis. Laboratory determina-
tions on the remaining sample portion were finished within one week of
initial collection. Samples were stored at 4 C during this period. Pas-
sing the sample through the 5.0 micron filter allowed the determination
of the soluble fraction pesticides.
Certain determinations were thought to be affected by freezing and
these were conducted on fresh, unfrozen aliquots. All determinations,
which were carried out on a sample which was preserved by freezing, were
verified by utilizing a test set of samples to determine the concentration
of the particular parameter before and after frozen storage.
185
-------
Gas Liquid Chromatography for the Analysis of Organophosphate.
Carbonate. S-Trizine, and Phenoxy Acid, and Chlorinated Hydro-
carbon Pesticides
The methods are rather specific for a particular compound. All pro-
cedures that are being employed are published procedures, or those used
by the company when registering the compound.
Confirmation of Residues by Mass Spectrometry
All samples from a given event for a given class of pesticides
were pooled and then analyzed by GLC-MS-CPU. Identities were confirmed
by comparisons of the samples' mass spectrum (11 masses with highest
intensity) with mass spectra of standards in the computer library.
Quality Control
Samples have been routinely exchanged between the Michigan State
University Pesticide Analytical Laboratory and the Pesticide Residue
Laboratory of the Michigan Department of Agriculture. These two labora-
tories are also involved in interagency and interlaboratory (IR-4) quality
control programs.
Pesticide Usage Survey
Since 1972, Michigan State University's Pesticide Research Center has
been maintaining computerized records of actual pesticide use on a farm-
by-farm basis within the watershed. Printouts such as shown in TABLE 13-1
are available for 90% of the farms in the basin. Other printouts such as
shown in Figure 13-2 can be obtained on demand from the author.
RESULTS
The Mill Creek system is an intricate and interactive system directly
related to discharge mechanisms. Our results show that as the flow rate
increases (volume increases) the pesticide in the soluble fraction is
diluted, but at the same time increased scouring of the land occurs carry-
ing into the stream an increased burden of pesticides in the adsorbed state.
186
-------
TABLE 13-1. TABULAR PRINTOUT OF PESTICIDE USE IN ONE FARM IN THE MILL CREEK BASIN
GROWER:
NYBLAD
1973
H IN KENT
COUNTY IN MICHIGAN
APPLES
15 ACRES
oo
PESTICIDE
X
APPS
AVERAGE
ACRES SPRAYED
AVERAGE
LBS/ACRE
PER CENT TREATED
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
X
CYGON X
ETHION X
GUTHION X
PB ARSNATE X
PHSPHMIDON X
SEVIN X
TEPP X
ZOLONE X
KARATHANE X
PLICTRAN X
SUPER. OIL X
CAPTAN X
CYPREX X
SULFUR X
2
1
4
8
2
4
2
2
4
2
1
23
7
15
7
7
11
7
7
7
7
7
15
8
13
7
07
25
,50
,09
,73
,38
,16
.20
.52
.38
55
1
90
.95
2.85
100
100
100
100
100
100
100
100
100
100
100
100
100
100
-------
KENT COUNTY IN MICHIGAN
GUTHION USE ON APPLES
oo
co
3.00
2.00
1.00
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
X
X
X
X
X
X
X
X
X
X X
XXX X
XX X XX X X X
XXXXX X XXX XXX X
XXXXXXXXXXXXXXXX X
XXXXXXXXXXXXXXXXX XX
XXXXXXXXXXXXXXXXX XX
X X
X XXX X
X XXX X
X XXX X
X XXX X
Figure 13-2.
MAR
APR
MAY
JUN
JUL
AUG
SEPT
OCT
Graphic printout example of application rates and seasonal distribution of
application for Guthion in the Mill Creek watershed (1976). Values in Ibs/acre.
-------
Pesticides that were found are Simazine, Atrazine, p,p'-DDT, p,p'-DDD,
p,p'-DDE, Aldrin, Dieldrin, and Guthion. The data suggest that the rela-
tive concentration of pesticide in water as to that in the suspended
matter is related to the individual pesticide. In general, the highest
concentrations are found at the beginning of a precipitation event (Figures
13-3, 13-4, and 13-5).
It is to be noted that of the 59 pesticides analyzed for TABLE 13-2,
the major pesticides found are still the chlorinated hydrocarbons and
Atrazine, Simazine and Guthion. The only organophosphate found was
Guthion. TABLES 13-3 through 13-7 give the summaries for the data col-
lected from the three automated sampling stations for 1976 and 1977.
TABLES 13-3 and 13-4 show that the suspended material (filtered pesticides)
is always consistently higher than the dissolved pesticide content of the
stream. These two tables also indicate that the descending hydrograph of
an event carries the greater burden of pesticide residue. The movement of
pesticide off the land into the stream lags behind the onset of any preci-
pitation event. TABLES 13-5 through 13-7 summarize the loading at the
automated sampling sites. It must be remembered that all data are based
on relatively few events since the summers of 1976 and 1977 were extremely
dry with few good precipitation events.
DISCUSSION
Any pesticide ecosystem involves many interactions. The Mill Creek
watershed is mainly an orchard ecosystem. The pesticide-orchard ecosystem
model consists of two parts, the orchard model and the stream transport
model.
The Orchard Model
The orchard model simulates pesticide dynamics between compartments
in the orchard. The model requires exogenous inputs of spray rate (kg/ha),
spray schedule, mowing schedule, tree state, rainfall amount, rainfall
derivation, rainfall intensity and timing of rainfall events; and outputs
2
daily pesticide magnitudes (yg/cm ) for each compartment.
189
-------
v£>
O
50r-
40
-------
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12
10
CX
CX
-------
vo
2.0
- 40 -
1.5
CO
W
a 1.0
o
•H
o
•H
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eu
0.5
- 30 -
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O
g
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Pesticide: Aldrin
Location: Mill Creek at M-37
Date: 6/17/75
S ' \
V- \
1600
2400
0800
1600
2400
0800
1600
2400
TIME
Figure 13-5.
Variation of pesticide concentration and flow rate over a hydrologic event.
(See Figure 13-3 for the legend.) (ppb = parts per billion, ppt = parts per
trillion)
-------
TABLE 13-2. PESTICIDES ANALYZED FOR IN THE MILL CREEK WATERSHED
Aldicarb
Aldrin
Atrazine
Benomyl
Binopacryl
Bromacil
Cacodylic Acid
Captan
Chlordimeform
Chloropropylate
2,4-D
DDD-p,p'
DDE-p,p'
DDT-p.p'
Diazinon
Dichlone
Demeton-0
Demeton-S
Dieldrin
Diphenamide
Dinocap
Dodine
Endosulfan I
Endosulfan II
Endrin
Ethion
Fenthion
Ferbam
Fundal
Gardona
Glyodin
Guthion
Heptachlor
Heptachlor epoxide
Hexachlo rob enz ene
Imidan
Isodrin
Kelthane
Lannate
Lindane
Malathion
Methyl parathion
Methoxychlor
Mevinphos
Omite
Paraquat
Parathion
PCNB
Phosphamidon
Plictran
Sevin
Silvex
Simazine
Systox
2,4,5-T
Tepp
Thiram
Trifluralin
Zineb
193
-------
TABLE 13-3. PESTICIDE EXPORTS FROM THE 3058 ha MILL CREEK WATERSHED, 1975-76 WATER YEAR*
VO
Pesticide
DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
Rising
Hydrograph (kg)
0.500 + .0002
0.361 + .0001
0.029 + .00001
0.043 + .00001
0.083 + .00003
0.079 + .00003
1.933 + .0006
0.174 + .0001
4.859 + .002
5.214 + .003
0.474 + .0002
0.526 + .0002
0.696 + .0003
0.451 + .0002
13.807 + .005
3.307 + .001
?T nui
Descending
Hydrograph (kg)
D I S S 0 L
15.427 + .013
13.228 + .012
1.063 + .001
1.159 + .001
2.669 + .004
0.688 + .002
39.247 + .124
2.898 + .005
F I L T E R E
281.440 + .09
196.550 + .13
17.420 + .017
1.570 + .002
17.107 + .024
6.612 + .018
283.030 + .85
50.644 + .172
Non-Event
Flows (kg) Total Exports (kg)
VED PESTICIDES
ND**
ND
ND
ND
ND
ND
ND
ND
D PESTICIDES
13.859 + 0.00 300.160 + 0.09
12.573 + 0.00 214.340 + 0.13
1.500 + 0.00 19.394 + 0.017
1.786 + 0.00 3.882 + 0.002
3.429 + 0.00 21.232 + 0.024
ND
ND
ND
Unit
Area
Loads
(kg/ha)
—
0.0982
0.0701
0.0063
0.0013
0.0069
—
**
There was 3.6 times more runoff in the 1975-76 Water Year than in the 1976-77 Water Year
ND indicates no data.
-------
TABLE 13-4. PESTICIDE EXPORTS FROM THE 3058 ha MILL CREEK WATERSHED, 1976-77 WATER YEAR*
VO
Pesticide
DDT
DDE
DDD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
DDT
DDE
DDD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
Rising
Hydrogra
1.
2.
0.
0.
0.
0.
0.
0.
24.
33.
1.
0.
1.
0.
7.
0.
852 +
284 +
097 +
113 +
244 +
007 +
791 +
036 +
136 +
261 +
015 +
945 +
912 +
151 +
152 +
706 +
-EVENT F
ph (kg)
.001
.002
.0001
.0001
.0001
.000004
.001
.00002
.020
.028
.001
.001
.001
.0001
.005
.001
>T nuc
Descending
Hydrograph (kg)
D
3.430 +
3.411 +
0.178 +
0.156 +
0.279 +
0.026 +
1.230 +
0.052 +
F
58.413 +
55.811 +
2.888 +
1.583 +
4.418 +
0.697 +
10.433 +
0.752 +
I S S
.036
.074
.006
.005
.014
.00002
.095
.004
I L T
0.647
1.261
0.102
0.067
0.235
0.447
0.675
0.061
Non-Event
Flows (kg)
0 L V E D
0.433 +
0.303 +
0.026 +
0.129 +
0.047 +
0.031 +
0.563 +
0.144 +
E R E D
3.001 +
2.732 +
0.209 +
0.182 +
0.377 +
0.510 +
5.537 +
1.486 +
P E S
7.104
1.245
0.000
0.553
0.276
0.232
12.865
4.140
PEST
5.201
10.424
1.674
1.239
2.841
2.600
42.580
22.590
Unit
Area
Total Exports (kg) Loads
(kg/ha)
TIC
5.
5.
0.
0.
0.
0.
2.
0.
I C I
85.
91.
4.
2.
6.
1.
23.
2.
IDE
715 +
998 +
301 +
398 +
570 +
064 +
584 +
232 +
D E S
550 +
804 +
112 +
710 +
707 +
358 +
122 +
944 +
S
7.104
1.247
0.006
0.553
0.276
0.232
12.865
4.140
5.241
10.500
1.677
1.241
2.851
2.638
42.585
22.590
0.00187
0.00196
0.00010
0.00013
0.00019
0.00002
0.00084
0.00008
0.0280
0.0300
0.0013
0.0009
0.0022
0.0004
0.0076
0.0010
There was 3.6 times more runoff in the 1975-76 Water Year than in the 1976-77 Water Year.
-------
TABLE 13-5.
FLOW WEIGHTED MEAN CONCENTRATIONS (yg/A) OF PESTICIDES
EXPORTED FROM THE 3058 ha MILL CREEK WATERSHED
- .
Pesticide
DISSOLVED PESTICIDES DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
FILTERED PESTICIDES DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
DISSOLVED PESTICIDES DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
FILTERED PESTICIDES DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
EVFNT
i_» V ULi X
Rising
Hydrograph
1975-76 WAT
0.531
0.366
0.052
0.094
0.097
0.112
2.245
0.201
5.192
5.341
0.799
0.738
0.884
0.535
16.327
3.828
1976-77 WAT
1.201
1.280
0.045
0.093
0.122
0.014
1.198
0.071
1.323
1.232
0.070
0.083
0.113
0.020
0.753
0.027
T7T OU^!
Descending
Hydrograph
E R YEA
4.166
3.572
0.287
0.313
0.721
0.186
10.598
0.782
75.998
53.075
4.704
0.424
4.619
1.785
76.428
13.676
E R YEA
13.727
15.885
0.640
0.501
1.063
0.351
6.862
0.725
19.831
18.769
1.053
0.585
1.559
0.498
5.624
0.408
Non-Event
Flows
R *
ND**
ND
ND
ND
ND
ND
ND
ND
1.940
1.760
0.210
0.250
0.480
ND
ND
ND
R *
0.170
0.119
0.010
0.050
0.018
0.012
0.221
0.056
1.176
1.071
0.082
0.072
0.148
0.200
2.170
0.582
There was 3.6 times more runoff in the 1975-76 Water Year than in the
1976-77 Water Year
ND indicates no data.
196
-------
TABLE 13-6.
STREAM EXPORT OF PESTICIDES FROM THE 1146 ha MILL CREEK
WATERSHED ABOVE THE CONFLUENCE WITH NORTH BRANCH
Pesticide
DISSOLVED DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
FILTERED DDT
DDE
DDD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
DISSOLVED DDT
DDE
DDD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
FILTERED DDT
DDE
DDD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
Flow Weighted
Mean Concentration
(yg/A)
1975-76 W A T E
1.167
0.740
0.073
0.073
0.154
0.046
3.448
0.243
17.480
11.530
1.030
0.985
2.356
0.564
27.122
5.173
1976-77 W A T E
0.666
0.522
0.023
0.052
0.058
0.010
0.483
0.014
5.293
4.156
0.198
0.194
0.505
0.218
4.053
0.231
Total Load (kg)
R YEAR
2.635 + 386.958
1.671 + 242.016
0.166 + 11.892
0.165 + 6.516
0.347 + 32.180
0.105 + 9.241
7.787 +1599.1
0.549 + 29.428
39.48 + 6,500
26.04 + 4,152
2.33 + 226
2.23 + 321
5.32 + 726
1.28 + 157
61.26 + 12,239
11.68 + 2,305
R YEAR
0.330 + 3.01
0.260 + 0.85
0.011 + 0.067
0.026 + 0.041
0.029 + 0.146
0.005 + 0.000
0.238 + 0.907
0.007 + 0.002
2.609 + 11.863
2.049 + 10.980
0.098 + 1.091
0.096 + 0.845
0.249 + 1.630
0.107 + 0.320
1.998 + 4.381
0.114 + 0.158
Unit
Area
Loads
(kg/ha)
0.0023
0.0015
0.00014
0.00014
0.00030
0.00009
0.0068
0.00048
0.0345
0.0227
0.0020
0.0020
0.0046
0.0011
0.0535
0.0102
0.00029
0.00023
0.00001
0.00002
0.00003
0.000004
0.00021
0.000006
0.0023
0.0018
0.00009
0.00008
0.00022
0.00009
0.0017
0.00010
197
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TABLE 13-7. STREAM EXPORT OF PESTICIDES FROM THE 889 ha NORTH BRANCH
SUBWATERSHED OF MILL CREEK
Pesticide
Flow Weighted
Mean Concentration
(wg/A)
Total Load (kg)
1975-76 WATER YEAR
DISSOLVED DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
FILTERED DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
DISSOLVED DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
FILTERED DDT
DDE
ODD
Aldrin
Dieldrin
Guthion
Atrazine
Simazine
0.994
0.786
0.068
0.153
0.195
0.047
3.892
0.305
15.680
10.813
1.247
0.925
2.017
0.582
28.993
5.580
1976-77 W A
0.689
0.695
0.021
0.068
0.071
0.011
0.417
0.018
8.028
7.456
0.376
0.311
0.847
0.194
3.860
0.268
1.953 + 286
1.545 + 174
0.133 + 17.5
0.301 + 37.9
0.384 + 63.9
0.093 + 10.27
7.653 + 1,247
0.600 + 26.91
30.84 + 4,813
21.26 + 2,877
2.45 + 286
1.82 + 223
3.966+ 520
1.145+ 144
57.02 + 8,646
10.97 + 1,773
T E R YEAR
0.304 + 6.301
0.306 + 10.496
0.009 + 0.104
0.030 + 0.708
0.031 + 0.469
0.005 + 0.026
0.184 + 1.304
0.008 + 0.017
3.541 + 110
3.290 + 88
0.166 + 2.21
0.137 + 3.94
0.374 + 7.85
0.086 0.572
1.703 + 11.23
0.118 + 0.681
Unit
Area
Loads
(kg/ha)
0.0022
0.0017
0.00015
0.00034
0.00043
0.00010
0.0086
0.00067
0.0347
0.0239
0.0028
0.0021
0.0045
0.0013
0.0641
0.0123
0.00034
0.00034
0.00001
0.00003
0.00003
0.000006
0.00021
0.000009
0.0040
0.0037
0.00019
0.00015
0.00042
0.00010
0.0019
0.00013
198
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The conceptual model of the orchard consists of 15 compartments from
three horizontal regions (trunk, canopy and alley), four to five vertical
strata (leaves, grass litter, moss, soil), and a runoff sink. The trunk
region represents a cylinder with a height equal to the height of the
tree and a diameter incorporating the tree trunk and a small neighborhood
around the trunk. The canopy region depicts a cylinder whose outer
boundary corresponds to the tree crown and inner boundary touches the
trunk cylinder. The alley region is everything not present in either the
trunk or canopy regions. Each region contains at least four strata:
grass, litter, moss, and soil; and the trunk and canopy region contains the
leaf stratum as well. Each vertical stratum is assumed to have a uniform
dispersion throughout each region.
Pesticide Application—
When spraying occurs, the amount of pesticide reaching each orchard
compartment is a function of the amount of pesticide applied, spraying
technique, local weather conditions, percentage of orchard ground surface
covered by tree canopies and degree of fullness for the average tree.
The amount of pesticide applied to the orchard is recorded as kg/ha. The
percentage of ground surface covered by the trees' canopy and degree of
fullness of the average tree is measured by a pesticide interception poten-
tial. The interception potential varies from zero, representing a dormant
orchard with a low tree density, to one, depicting a very dense orchard
with healthy, full trees. The interceptional potential varies during the
growing season to reach a maximum value at approximately harvest time;
the maximum value is orchard specific. The relationship between the
pesticide distribution and interception potential was modeled by a trun-
cated Maclaurin series expansion; represented for the i compartment as
Ai " ai + biX
where A is the proportion of pesticide intercepted by the i
compartment,
a. is a distribution constant,
b. represents the change in pesticide allocation to the i com-
partment as a function of the change in interception potential,
199
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and X is the interception potential.
It should be noted that a± and b± are dependent on the spraying technique
employed.
Local weather conditions are assumed to have an insiginficant effect
on the spray distribution since spraying only took place under favorable
weather conditions.
The amount of pesticide to be added to the ith compartment then becomes
yi = ^ai + biX^S
where a±, b±, and X are defined above,
S is the spray rate (kg/ha),
and y± is the amount of applied pesticide that reaches the ith
compartment.
Pesticide Attenuation—
Pesticide attenuation is the process in which microbial degradation,
photochemical degradation, volatilization, chemical degradation and inver-
tebrate accumulation and degradation remove pesticide from the orchard eco-
systems. Accurate prediction of attenuation losses must therefore delin-
eate the relationships between these attenuation mechanisms and the environ-
mental conditions which regulate each mechanism.
Field tests have shown that microbial degradation of parathion may
be directly dependent on soil PH and organic matter and soil moisture and
temperature; however, physicochemical characteristics of soil, such as its
adsorption properties, protect atrazine and diquat molecules from micro-
bial attack. Photochemical degradation of atrazine and azinphosmethyl
occur when subjected to light of wave-length 253.7 nm. Volatilization
of pesticide is dependent on its vapor pressure, moisture, temperature,
and degree of adsorption. Invertebrate accumulation and degradation of
pesticides depends on the environmental parameters such as air and soil
temperature, soil moisture, and soil organic content which controls a
species' physiological development, metabolic rate, survival and reproduc-
tion. Chemical degradation of diazinon and atrazine is adsorption cata-
lyzed; that is, as the degree of adsorption to soil particles increases,
200
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chemical hydrolysis and thus degradation increase. The degree of adsorp-
tion is, in turn, affected by type of soil colloid, pH, temperature,
moisture and organic matter.
Consequently, the final predictive form of the pesticide attenuation
submodel must consider air and soil temperatures, soil moisture, soil
organic content, soil pH, solar illumination, and the vapor pressure of
the given pesticide in order to accurately estimate pesticide losses.
Presently, the functional relationships between pesticide attenuation
and the environmental variables have not been elucidated, so pesticide
attenuation is temporarily modeled by combining all the attenuation mech-
anisms into a constant first order degradation rate. By calculating a
degradation rate for each compartment, a portion of the variation in the
environmental variables between compartments can be accounted for, although
seasonal dynamics cannot.
The present attenuation equation for the i compartment is:
where P' and P. are the amount of pesticide present at time T+l
and T, respectively,
and d. is the compartment-specific attenuation rate.
Physical Alteration —
Farming techniques (disking, pruning, mowing , irrigation) alter the
physical structure of orchards and thus alter pesticide dynamics. Since
pruning occurs during the winter and since the study focuses its attention
on pesticide dynamics during the growing season, pruning is not considered.
Irrigation is not applicable to Michigan orchards since rain provides
sufficient moisture. Disking is used in some Michigan orchards to control
rodents and undesirable vegetation; however, disking is not used in the
orchard field experiments and is not considered in the model. The princi-
pal method used to control grass is mowing; which results in moving pesti-
cide from the grass to the litter. The amount of pesticide moved from
the i grass compartment to the j litter compartment is modeled by:
C± - (P±)(M)
201
-------
where C. is the amount of pesticide moved,
J
P± is the amount of pesticide present in the i grass compart-
ment,
and M is the proportion of pesticide moved during a single mowing
event.
Climatic Data—
Several climatic variables are very important in determining the fate
and impact of pesticides on apple orchards. These include amount of rain-
fall, intensity of rainfall, duration of rainfall, and soil temperature.
The intensity of rainfall is assumed to be the primary driving
mechanism for moving pesticide between vertical strata. The intensity,
magnitude and duration of rainfall principally determine soil saturation
and runoff. Soil temperature and soil moisture as stated are instrumental
in determining pesticide attenuation.
Amount of rainfall, rainfall intensity, and duration of rain activity
are inputed directly into the model on a rainfall event basis. Daily
minimum and maximum air temperatures, collected approximately ten miles
from the experimental site, are inputed and converted into minimum and
maximum soil temperatures by Fourier transforms.
Movement in Soil—
Pesticide mobility in soil results from the interaction of soil
particle adsorption-desorption, chemical reaction, pesticide solubilities,
water flux, and the physical properties of the soil. However, the move-
ment of azinphosmethyl within the soil profile can be principally explained
as a negative relationship to field moisture capacity. This relationship
suggests that azinphosmethyl is strongly held to soil particles. Conse-
quently, azinphosmethyl mobility within the soil is very low; thus,
pesticide mobility is assumed to have an insignificant contribution to
pesticide dynamics and is not modeled. As new pesticides are added to the
orchard model, the importance of soil mobility will be reevaluated.
202
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Vertical Movement —
During a rain event pesticide moves vertically from the higher orchard
compartments toward the lower in each region. The proportion moving is a
function of the degree of canopy fullness and intensity of rainfall.
Rainfall intensities are classified into one of three intensity
categories — light, moderate, or heavy, from which unique E and F matrices
are determined for each intensity class.
The degree of canopy fullness, "tree state," depicts the obstruction
to rainfall created by the average tree within the orchard. The value
assigned to the tree state ranges from zero to one, with zero representing
a condition where only dormant trees are present and one representing a
very large, full tree such that the alley is almost completely obscured.
The relationship between tree state and proportion of pesticide is modeled
by a truncated Maclaurin series expansion.
The model for the vertical movement matrix representing the proportion
of pesticide moving vertically from the i compartment to the j com-
partment in response to a rainfall of intensity class k is
where t represents the tree state of the average tree within the
orchard,
is the vertical movement proportions when the tree state
is zero ,
accounts for change in proportion of movement corresponding
to any change in tree state,
and V.. is the proportion of pesticide moving from compartment i
to j.
The effect of rainfall intensities on pesticide movement is, there-
fore, modeled as a discrete approximation; while, the degree of canopy
fullness provides a continuous measure.
To describe tree state, the maximum value of tree state or the tree
state present just preceding harvest is inputed during model initializa-
tion.
203
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Lateral Movement—
During a runoff event pesticide is redistributed within the soil
region of an orchard, but more importantly runoff provides a mechanism
for the pesticide to leave the orchard. Runoff provides the driving
mechanism for lateral redistribution of pesticide. Consequently, to
predict the amount of pesticide lost, runoff and the amount of pesticide
coupled to runoff must be modeled.
Runoff was modeled on a single rainfall event basis by utilizing a
modified rational method to predict the rate of runoff:
R = (C)(I)(A)
where R represents the greatest runoff rate occuring for a single
rainfall event,
C is a function of the orchard surface characteristics and the
amount of rainfall from the storm being considered,
I is the average intensity of rainfall,
and A represents the area of the watershed.
Presently, the modified rational method provides a crude but adequate
estimate of the rate of runoff. If greater accuracy and precision is
desired in predicting runoff, other runoff models such as the ARM could
be coupled directly.
The mechanism which couples pesticide movement to runoff rate must
describe the relationship between runoff and the desorption of pesticide
from soil particles, the dissolution of stationary pesticide particles,
the scouring and transport of soil particles on which pesticide is adsorbed
and the diffusion of dissolved pesticide from the soil interstices. The
coupling mechanism is assumed to be a function of runoff and is defined as:
PR - 1 - e~AJR
.m
where PR represents the proportion of pesticide removed from the
th
m compartment,
R is the runoff rate,
and A is a coefficient describing the availability of pesticide
to runoff coupling process for the j compartment.
204
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This equation also produces a crude but adequate mechanism for pesti-
cide uptake by runoff. If greater precision is desired, alternative
coupling mechanisms can be implemented.
Runoff over the orchard is assumed to be uniform so the proportion
of pesticide removed from the m vertical stratum is equivalent for all
regions
PRn = PR0 = PR,
J. ,m 2. ,m J ,m
The proportion of pesticide removed from a given region is then redistri-
buted into the soil stratum of the other regions or lost into the drainage
area according to a proportion defined by the relative length of edge
between adjacent regions.
The coupling equation generates a proportion which characterizes the
redistribution of pesticide from the m vertical stratum in the n
region to the soil stratum in the n region based on runoff rate. These
proportions are then multiplied by the amount of pesticide present in each
compartment to provide a measure of pesticide lateral movement.
3 5
P ' .n = £ )> PR x P n' = 1,2,3
n ,soil L L n,m n,m
n=l m=l
where PR is the proportion of pesticide removed by runoff,
n 9 in
P represents the amount of pesticide present before
n,m
runoff,
i i
and P • ., is the amount of pesticide moved into soil region n
n ,soil K
after runoff.
Transport Model
As can be seen from the results section the adsorption of pesticides
on particulate matter is extremely important in the Mill Creek watershed.
Unlike other substances, such as inorganic ions (phosphates, nitrates)
which readily dissolve, pesticides either emulsify, precipitate, or have
a low solubility and remain in colloidal form or adsorb to particulate
matter.
205
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Association of pollutants with particulate matter in water greatly
alters their subsequent fate. Compounds in solution are only available
for uptake by organisms by absorption through membranes. Once precipitated
or adsorbed, however, ingestion of concentrated amounts becomes possible.
Also dispersal then follows sedimentation patterns of natural suspended
material and the behavior of non-soluble pollutants becomes directly
related to the dynamics of naturally occurring particles.
When a compound is added to water, it will either dissolve and enter
into true solution, or remain insoluble and form a colloidal or parti-
culate suspension. The initial state which a pollutant assumes determines
its subsequent fate (Figure 13-6). Compounds of low solubility such as
hydrophobic pesticides may be solubilized to some extent by association
with surface active humic-like organic matter. Such compounds usually
form emulsions. Also if concentrations approach or exceed compound solu-
bility, accumulation occurs at the air-water interface where evaporation
occurs. Chlorinated pesticides show this behavior and empirical equations
have been derived to calculate potential evaporation rates for hydrocar-
bons of known vapor pressure and solubility.
Pesticides which do not dissolve become an integral part of the total
suspended material and flocculate in a manner similar to naturally occur-
ring suspended particles.
Pollutants like radionuclides and nutrients which dissolve or like
hydrocarbon pesticides which form colloidal suspensions have apparent
solubilities which are greatly affected by adsorption-desorption reactions
with suspended particulate matter. Studies have indicated that suspended
solids and colloidal gels can rapidly adsorb nutrients like phosphate. It
has been demonstrated that equilibrium concentrations between individual
sediment particles and water are reached quickly. Uptake to saturation
levels, which varied inversely with particle size, was largely complete
within 10 minutes, 50% of maximum values being reached after one minute.
Desorption rates were slower. Desorption stabilized after an hour but
final equilibrium concentrations were different for different pesticides.
Adsorption-desorption processes also greatly affect the distribution
of organic hydrocarbons in water. The hydrophobic nature of many of these
206
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ADSORPTION AND TRANSPORT PROCESSES
OF POLLUTANTS ON SUSPENDED PARTICLES
NATURE OF
POLLUTANT
SUPPLY
SOLUBILIZATION
BIOLOGICAL
PRODUCTION
FLOCCULATION
AGGREGATION
SEDIMENTATION
BURIAL
BIOLOGICAL
CONSUMPTION
ACCUMULATION
TRANSPORT
DISPERSION
METABOLIC
DEGRADATION
TRANSFORMATION
Figure 13-6.
Schematic outline of major processes which affect adsorp-
tion and transport of nonsoluble pollutants in water.
207
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substances results in colloidal suspensions and accumulation at inter-
faces making determinations of true solubilities difficult. Qualitative
and quantitative differences exist in pesticides associated with various
size classes of microparticulate matter in natural water and it is possible
that most hydrophobic compounds are bound to such particles. It has been
pointed out that most particulate surface area in natural waters is ac-
counted for by suspended matter < 2 y diameter and it seems likely that
hydrophobic compounds will usually be bound to these particles.
Adsorption-desorption processes of pesticides in soil have been
extensively reviewed. Particle surface area, charge and organic content
determine adsorptive capacity in conjunction with water solubility and
charge distribution. Researchers have indicated the extensive adsorptive
capacity of clay particles and colloidal humic material for chlorinated
hydrocarbons. Adsorption to suspended clay and sediment occurred by
physical adsorption-desorption equilibria whereas adsorption to humic
acid occurred by lipophilic binding and capillary adsorption within the
humic polymer. Physical rather than chemical adsorption through the forma-
tion of weak hydrogen bonds appear to be the primary mechanism for uptake.
Numerous empirical plots can be used to describe adsorbed concentra-
tions as a function of the concentration remaining in solution. Compounds
of relatively high solubility (like nitrophenol) may form saturated mono-
layers, so that uptake becomes asymptotic above certain concentrations.
Langmuir isotherms describe uptake of these compounds. Adsorption of less
soluble compounds, present below saturation levels, however, is usually
logarithmically related to concentration, and uptake follows a Freundlich
plot
X = K Cn (1)
where X is the amount adsorbed per unit weight of adsorbent, C is the
equilibrium concentration in solution, and n and K are constants (slope
and intercept) which represent the extent (capacity) and nature of adsorp-
tion, respectively.
Uptake from dilute concentrations of DDT by various particles was
described by Freundlich isotherms with n = 1. Data for uptake experiments
show a similar slope constant. The experiments were repeated using
208
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various particles exposed to lindane, aldrin and dieldrin. The slope con-
stants for Freundlich plots were between 0.80 and 1.70 with a mean value
(1.04) similar to published values derived for other compounds. This indi-
cates physical binding with absolute values of n determined by the degree
of competition of solvent for sites on the adsorbing surface.
Values of K are an indirect measure of the extent of adsorption.
Increased temperature results in decreased values of K indicating the
exothermic nature of adsorption which may be proportional to relative
free energy changes. K values are also inversely related to particle
diameter by the equation
K = a d~b (2)
where D is the spherical equivalent of particle diameter (y) and a and b
are constants. Organic matter in lake sediment and soil is a major deter-
minant for adsorption of non- ionic pesticides. The importance of organic
content is further substantiated by a reduction of marine sediment adsorp-
tion capacity for DDT by removal of humic material. Similarly, DDT uptake
by sediment of various grain sizes was reduced an order of magnitude after
ashing.
These observations suggest that a general expression for equilibrium
concentrations of hydrophobic compounds on particles of various sizes may
be of the form
Cn
X = ^ (3)
AD
by combining equations (1) and (2) . Further expansion to standardize
for an effect of organic content on adsorption would be to express uptake
per unit organic carbon (or a related index of organic material) . Thus ,
a D
Uptake per unit organic matter is directly related to the concentration
of a hydrophobic compound in solution and particle surface area available
for adsorption. Organic content is often inversely related to particle
diameter, however, and thus comparisons of K values and particle size may
209
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include effects of this variable. This would explain why over 90% of the
variation in uptake by particles ranging in size from bacterial cells to
sand grains can be accounted for by only considering differences in median
particle diameter and DDT concentration.
Desorption of hydrophobic compounds from particles depends on the
nature of the binding, compound solubility, and the length of time avail-
able for desorption. For example, DDT adsorbed to humic acid is not
desorbed as readily as that on clay or sediment. Compound solubility is
also critical in determining loss rates through desorption. Little DDT
is lost from sand on rinsing, but lindane and dieldrin are readily lost
in proportion to their solubilities. Thus, just as compound solubility
determines the concentration available for adsorption to particle surfaces,
it also determines desorption rates when concentrations in solution are
reduced.
Initially pollutants retain the physical state in which they were
introduced and in this state are acted on by physical forces. For example,
pollutants associated with coarse-grained sediment dumped from a barge onto
mud bottom may never become resuspended for further transport. Fine-
grained particulate effluent may disperse widely before flocculating.
Once particles are suspended in a turbulent environment they interact
and flocculate with each other and the naturally occurring particles
thereby changing their size and hence their transport behavior. The exact
mechanism of particle interaction and aggregate formation is poorly under-
stood and only partly predictable at the present time.
Attraction due to molecular forces within the particles and/or adhe-
sion due to organic coatings on surfaces is believed responsible for floc-
culation. Some mineral species appear to folcculate more readily than
others. Observations with natural suspended particulate matter show that
organic matter forms an integral part of floes. This is not surprising
since all surfaces in contact with sea water appear to become coated with
organic material. The action of bacteria adhering to particle surfaces
may be important in binding floes. This would diminish the importance of
mineralogy in controlling flocculation.
210
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Sediment flocculates in sea water into aggregates the size of which
are dependent on the grain size of inorganic particles. There is a loga-
rithmic relationship between the modal size of the single deflocculated
constituent grains. Flocculation occurs until all particles have approxi-
mately the same dynamic transport speed and no longer come into contact
with each other. Since particle size and density rather than composition
appear to be the controlling factor, the distinct flocculation behavior
reported for minerals such as montmorillonite may be a product of their
distinct grain size rather than their surface chemistry. Pollutant parti-
cles such as organic pulp mill effluent also become incorporated in the
natural floe distribution, lose their individual physical characteristics
and are transported as part of the natural sediment load.
The extent to which suspended particulate matter in fresh water is
flocculated is not known. According to classical concepts massive floc-
culation takes place as unf locculated river sediment comes into contact with
saline estuarine water. Some workers, however, have documented the impor-
tance of flocculation in lacustrine sedimentation. If bacteria are
indeed a significant factor in particle flocculation, then flocculation
should be as prevalent in fresh water as in the sea.
Microscopic observations of fresh water particulate matter show
that a high proportion of the particles consist of aggregates. The grain
size spectra show smooth nearly symmetrical distributions similar to those
of marine particulate matter. Since all natural particulate matter con-
tains particles from multiple sources with discrete grain sizes, the
size distributions should be irregular multimodal if no interparticle
reaction has taken place.
Once pollutants become associated with particles their fate is essen-
tially dependent on the transport and dispersal of the particles them-
selves; they can be sedimented or transported and dispersed. Both can be
transitional in that sediment can be eroded and resuspended or sedimented
many times.
The transport and dispersal of particles is dependent on the transport
rate of the water and on the relationship of the transport rate of parti-
cles to that of the water. Dissolved pollutants can be expected to dis-
perse at the same rate as the parcel of water into which they were
211
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introduced. But particles usually have specific gravities greater than
that of the water and gravity and inertia will give them a slower net
motion. Only very small particles and particles with densities close to
that of water will behave as dissolved substances. Progressively larger
and heavier particles will have transport histories increasingly different
from that of the water they are suspended in, and particle size and density
are of primary importance in prediction of their transport behavior.
Models to predict transport rate of suspended sediment in relation
to dynamic water transport are presently imperfect. The movement of large
sand and silt particles transported as bedload with a rapid exponential
decrease in concentrations away from the bottom is best understood. Their
behavior has been studied in numerous laboratory and theoretical investi-
gations. The fine-grained suspended load, composed mostly of cohesive
material less than 16 microns, shows physical behavior different from that
of the bedload and are easily distinguished from the bedload in grain size
analysis of bottom sediments. Suspension of the material is largely
dependent on levels of microturbulence and the highest concentrations are
often encountered near the surface and near the bottom of a water body
as well as in association with density layers within the water column.
At present the best guide to where particles of a given size will be
deposited seems to be an empirical study of geological conditions along
an aquatic pathway. For example, whether or not a pollutant associated
with particles of a certain size can become deposited in a lake along a
waterway or trapped in the turbidity maximum of an estuary may be deter-
mined by comparison of natural sediment grain size and that of the polluted
material.
In conclusion it can be shown that pollutants entering the aquatic
environment readily become associated with natural suspended particles.
Dissolved compounds are adsorbed onto particles and substances in particu-
late form flocculate with other particles. The division between true sol-
utions and colloidal suspension may be difficult to determine and is of no
practical significance if both forms ultimately become associated with
other particles.
Particle size and concentration are of prime importance in predicting
transport and dispersal of pesticides. While the organic nature and surface
212
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charge of suspended particles affect adsorption, particle size and number
(i.e., total surface area) may be the most important factor determining
adsorption of non-soluble pollutants in water. Transport of particles
after adsorption and flocculation is dependent on the relationship between
grain size and the turbulence of the hydraulic environment.
SUMMARY
The results show that pesticides (chlorinated hydrocarbon pesticides
in particular) are still a significant non-point source of contamination
to Michigan rivers and consequently the bordering Great Lakes. The con-
centrations found are at the part per billion and trillion level but are
still significant in terms of their effect on aquatic organisms due to bio-
magnification. The results of Mill Creek are supported by the fact that
pesticides such as DDT and Dieldrin are found in Great Lakes fish and are
responsible for the ban on commercial fishing for Coho salmon, etc.
There does not appear to be any reasonable mechanism for the elimina-
tion of these pesticides from the river and streams short of what has
already been implemented (ban on the use of chlorinated hydrocarbon pesti-
cides). Prevention of sheet soil erosion would certainly be a measure
that would reduce the amount of pesticides entering the Great Lakes but
would certainly not stop the introduction of all pesticides due to evapo-
ration, drift, and other transport processes.
213
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-905/9-78-002
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
THE FELTON-HEKRON CREEK, MILL CREEK PILOT WATERSHED
STUDY
5. REPORT DATE
June 1978
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Thomas M, Burton
8. PERFORMING ORGANIZATION REPORT NO.
3. PERFORMING ORGANIZATION NAME AND ADDRESS
Institute of Water Research
Michigan State University
East Lansing, Michigan 48824
10. PROGRAM ELEMENT NO.
2BA645
11. CONTRACT/GRANT NO.
R005143-01
12. SPONSORING AGENCY NAME AND ADDRESS
Great Lakes National Program Office
U.S. Environmental Protection Agency
230 South Dearborn Street
Chicago, Illinois 60604
13. TYPE OF REPORT AND PERIOD COVERED
Grant - May 1974 to March 1978
14. SPONSORING AGENCY CODE
EPA-GLNP
15. SUPPLEMENTARY NOTES
Thomas G. Bahr was Principal Investigator for this project.
16. AB TRACT ^^ effects of fruit orchard farming and land application of wastewater on
transport of pollutants to the Great Lakes were studied in two sub-studies. In the
Mill Creek Study, movement of pesticides from fruit orchards was the primary concern.
Only eight pesticides were transported in appreciable quantity. The major forms
exported were the residual, presently unused, chlorinated hydrocarbons. Most pesti-
cides were transported on suspended solids. Pesticides lost in order of amount lost
were DDT, DDE, Atrazine, Dieldrin, ODD, Simazine, Aldrin, and Guthion. Most pesti-
cides lost were associated with past farming practices or corn cultivation. Guthion
was the only major pesticide lost associated with present fruit orchard farming
practices. The Felton-Herron Creek Study demonstrated that improper management of
land application systems for recycling municipal wastewater can lead to appreciable
loading of streams with major nutrients, especially nitrogen. Proper management can,
control these losses. Perennial crops and oldfield systems are efficient at uptake
of both N and P throughout the growing season and offer excellent wastewater renova-
tion potential. Annual crops such as corn are not efficient at nitrogen uptake during
the first five to seven weeks, but are efficient after that. Losses of N to ground
water or runoff often approach input amounts in wastewater irrigated forests. A
variety of harvest managements and winter spray feasibility were investigated in this
study and are discussed in detail.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COS AT I Field/Group
Water quality, runoff, pesticides, sewage
effluent, land disposal, wastewater
recycling, euthrophication, nutrient
cycling, orchards, crop management, and
watersheds.
Michigan State University
Water Quality Management
Facility, Great Lakes
Basin, International
Joint Commission, and
Oldfields.
18. DISTRIBUTION STATEMENT
Document available
U.S. EPA, Chicago, IL, and through the
National Technical Information Service
(NTIS), Springfield, VA. 22161
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
230
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
*U.S. GOVERNMENT PRINTING OFFICE: 1979—650646
214
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