POWER LINE RIGHT OF WAYS AND WATER QUALITY DEGRADATION
Douglas C. Williams, Department of Earth Sciences, University of South Alabama,
Mobile, AL 36688. E-mail: douglas.williams1@comcast.net.
Alabama Power Company is planning to construct a power line right of way in the
floodplain adjacent to Milkhouse Creek’s tributary north of Grelot Road. A 100 foot
wide clearing would be required for the right of way to be completed. The right of way
would begin at Grelot Road and extend northward and tie into a substation near
Providence Hospital. The clearing would destroy wetland vegetation, trees and the
wildlife habitat. Residents in the area are against this construction because they feel it
will ultimately lead to the degradation of the water quality of Milkhouse Creek, Halls
Mill Creek and eventually Dog River. My objective is to obtain sufficient background
water quality data from a sampling location just south of Grelot Road and the proposed
right of way. This will enable local environmental groups, such as Dog River Clearwater
Revival, to determine if this construction does indeed have a negative impact on the
water quality. Another objective is to develop a digital photo archive of the current
conditions of the stream and floodplain in order to compare them to the area if Alabama
Power is successful in getting this right of way completed. My conclusions will show
what the current water quality is and additionally present the current conditions of the
stream and surrounding floodplain.
Keyword: water quality, right of way, transmission line
Introduction
Alabama Power Company is planning to build a power line right of way (ROW)
along a tributary of Milkhouse Creek between Providence Hospital and Grelot Road in
Mobile, Alabama (Figure 1). The forest that is adjacent to the creek in the proposed
construction area consists of old growth pine and hardwood trees (Save Milkhouse Creek
2008). The construction of the right of way would require that one hundred feet of
existing vegetation, trees and grasses be destroyed. Additionally, Alabama Power would
have the right to cut any “danger trees” outside of the ROW that could possibly fall and
damage the power lines or poles (Save Milkhouse Creek 2008). These trees and
vegetation are critical for “cleaning up” any runoff water before it enters the creek and
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also can serve as a barrier to slow down any flood waters. Due to these natural cleaners
being destroyed, the creek would receive more sediment, trash and other contaminants.
Figure 1 Location of proposed transmission line along Milkhouse Creek (in green).
Google Earth Image courtesy of the Save Milkhouse Creek website.
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Milkhouse Creek is tributary of Dog River; therefore, any new contaminants could
ultimately end up flowing into Halls Mill Creek, Dog River and Mobile Bay. Water
quality in Milkhouse Creek could ultimately be degraded including increased turbidity
from additional sediment, decreases in dissolved oxygen (D.O.), and rise in water
temperatures due to more direct sunlight. Wetlands help prevent water quality
degradation (NU transmission 2008) Electric utilities find wetlands to be a desirable area
for construction of power transmission lines because they are free from major
obstructions, low in price and away from public view (Thibodeau and Nickerson 1986).
Alabama Power could find an alternate route or even consider underground power lines.
There are clear advantages to having urban power lines underground. However, power
companies operate in monopoly status and usually have no incentive to accommodate the
public (Maney 1996).
Research Question
What is the current condition of the water quality of the tributary of Milkhouse
Creek down-stream of the proposed ROW? Additionally, what is the current condition of
the stream and the floodplain of the tributary where Alabama Power is planning its
ROW?
Methods
To determine whether the water quality of the tributary will be affected by the
construction of the ROW, I collected background data down stream of where the ROW is
planned to be constructed. The location is located just south of Grelot Road and is
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located geographically at N 30º 39.658’ latitude and W 088º 12.122’ longitude. The site
location is shown on the Project Location Map (Figure 2).
Figure 2 Project Location Map
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A total of eleven water quality sampling events were conducted in order to have
sufficient background data. Alabama Water Watch test kits were used to test the water
for temperature, pH, alkalinity, hardness, dissolved oxygen and turbidity. The pH of the
water is a measure of the acidity of water. A scale of 0 to 14 is used, with seven
considered neutral. Any reading below seven is considered acidic and above seven is
basic. Alkalinity is the measure of the water’s buffering capacity. The higher the
alkalinity of the water is, the higher the buffer against changes in the pH of the water.
The hardness is a measure of the dissolved calcium and magnesium in the water. The
dissolved oxygen is a measure of the oxygen in the water and is critical for any aquatic
life. Turbidity is the measure of the cloudiness of the water. The majority of the samples
were collected at approximately 10:00 a.m. However, several samples were collected at
approximately 1:00 p.m. According to the Alabama Water Watch Certification course,
the time period in which water quality samples should be collected is between 10:00 a.m.
and 2:00 p.m. I chose to collect samples at the beginning and end of the time period in
order to see if any change occurred during those hours. One sample was collected after a
major rain event in order to evaluate whether heavy rainfall has an affect on water
quality. In addition to the water quality data collected, I took a series of digital
photographs in order to document what the current conditions of the tributary itself and
the surrounding floodplain are. For example, a picture of my chosen water quality
sampling location was taken at normal conditions and after a heavy rainfall event
(Figures 3 and 4). The remaining pictures of the tributary and surrounding floodplain are
included as Appendix A.
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Figure 3 Picture of water quality sample location during normal flow
Figure 4 Picture of water quality sample location after heavy rain event.
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Results
The results of the water quality sampling indicate that the water in the tributary is
relatively in good condition at the study area. The temperature of the water ranged from
14º Celsius to 18º Celsius (Figure 5). The pH remained at a slightly acidic 6 to 6.5. The
alkalinity and hardness remained consistent over the sampling period, except after the
heavy rain event. The dissolved oxygen ranged from 7.5 to 8.4 mg/L (Figure 6). The
turbidity of the water was clear except for after the heavy rain event where it climbed to
30 JTU (Figure 7). The results of the digital photographs taken indicate that the tributary
and stream are in good condition and are relatively free of debris or trash. The tributary
is surrounded by various forms and species of vegetation, trees and wildlife.
C omparis on of Air and Water T emperatures
for Milkhous e C reek
30
25
˚C
20
15
10
5
Air T emperature
W ater T emperature Figure 5 Comparison of Air and Water Temperatures
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4/21/2009
4/14/2009
4/7/2009
3/31/2009
3/24/2009
3/17/2009
3/10/2009
0
Dis s olved O x yg en, Alkalinity and Hardnes s in Milkhous e C reek S ample L oc ation
60.0
50.0
40.0
30.0
20.0
Rain
10.0
D is s olved O xygen T otal H ardnes s T otal Alkalinity Figure 6 Dissolved oxygen, alkalinity and hardness at sampling location
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4/21/09
4/14/09
4/7/09
3/31/09
3/24/09
3/17/09
3/10/09
0.0
T urbidity in Milkhous e C reek 35
30
J TU
25
20
15
10
5
4/21/2009
4/14/2009
4/7/2009
3/31/2009
3/24/2009
3/17/2009
3/10/2009
0
Figure 7 Turbidity of water at the sample location
Discussion and Conclusions
If Alabama Power is successful in their attempt to construct the ROW at the
present location, the water quality in the stream and the surrounding floodplain would be
negatively impacted. If the 100 foot ROW is cleared, the stream would have no
protection from direct sunlight to the stream. It is not only the 100 foot easement, but
also the space around it where it would let unwanted sunlight in the woods where it
doesn’t belong. It could change the plant life of the area (Carbery 2007). This could
ultimately raise the temperature of the water of the tributary and affect the dissolved
oxygen. Small minnows and other wildlife were observed in the stream and could be
affected by this temperature rise. Additionally, the vegetation and trees act as a barrier
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for the flood waters that occur during very heavy rain events. By clearing the vegetation
and trees, flooding could be worse than normal. There would be nothing to slow the
flood waters down and they could eventually wash out Grelot Road if it were to get high
enough. Utility right of ways through wetland areas can generate long-term impacts to
these valuable ecosystems (Nickerson et al. 1989). The residents in the area are against
the construction of the ROW at its present proposed location. They argue that there are
already poles set on Cody Road and Alabama Power could run its new transmission lines
along that route instead. In an article regarding the proposed project (Mobile Register,
March 29, 2009), critics insist that a power line ROW is a sure-fire recipe for increased
erosion. However, at the present moment, Alabama Power insists that it is going to
construct the ROW as planned. At present, there is no planned starting date for the
project. There have been several court hearings on the project, but so far rulings have
leaned toward Alabama Power. If the ROW is completed as planned, I will volunteer to
continue to monitor the water quality of the tributary of Milkhouse Creek in order to
assess whether there is a negative impact.
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References Cited
Alabama Water Watch Water Chemistry Monitoring, 2008
Carbery, K. 2007. Cedar Hill: Power Line opponents send message to Ameren.
Suburban Journals Sunday October 7, 2007.
Maney, C.T. 1996. Benefits of underground power delivery. Technology and Society
Magazine, IEEE 15:12-22
Nickerson, N. Dobberteen, R., Jarman, N. 1989. Effects of power line construction on
wetland vegetation in Massachusetts, USA. Environmental Management 13 (4)
477-483.
NU Transmission. http://transmission-nu.com/residential/NURightsofWay.asp
Save Milkhouse Creek. http://savemilkhousecreek.org (assessed on March 3, 2009)
Thibodeau, F, and Nickerson, N., 1986. Impact of Utility Rights-of-way on Wooded
Wetland. Environmental Management 10 (6) 809-814
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Appendix A-Additional pictures of the current status of the stream and floodplain
Area behind Mr. Jim Mitchell’s house
(Lamplighter Woods). Looking North.
Area behind Mr. Jim Mitchell’s house. Looking
North. AL Power flagging in trees.
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Area behind Mr. Jim Mitchell’s house. Looking
South. AL Power flagging in trees.
Alabama Power clearing near Providence
Hospital and beginning of tributary
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Alabama Power flagging crossing dry steam bed
of tributary
Part of tributary just east of Somerby Housing
Community. AL power clearing to west.
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Part of tributary floodplain area looking west
from Somerby. ROW would run through this
area
Alabama Power location near Providence
Hospital that ROW would be routed to.
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Normal tributary flow under Grelot Road toward
Milkhouse Creek.
Tributary flow under Grelot Road toward
Milkhouse Creek after heavy rains.
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