Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

Campus Runoff Water Quality Assessment

Hopkins, Sierra

Unity College Project Leader Research Report

Advisor: Dr. James Killarney

Spring 2019

Due 5/9/2019

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Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

Introduction

Polycyclic Aromatic Hydrocarbons (PAH) among other runoff contaminants are often present in

local environments and watersheds around urban development. A primary focus of this study is to

determine the contamination concentration changes from the top of the hill on campus, following the

runoff down slope, to the bottom of the hill where the retention pond collects all surface water runoff.

Samples in Sandy Stream will also be collected. Sampling, testing, mapping and analyzing the water

quality is essential to ensure overall watershed and the associated terrestrial and aquatic habitats

health. My study will hopefully framework the water quality of the campus runoff based upon parking

lot contaminants, PAH’s and petroleum-based leakages, and other human introduced chemicals that

reside on this campus.

Hydrocarbons, including Polycyclic Aromatic Hydrocarbons (PAH), among other runoff

contaminants are often present in local environments and watersheds around urban development.

PAH’s are a class of organic compounds produced by partial combustion or high-pressure processes.

They form when complex organic substances (such as petroleum or coal) are exposed to high

temperatures or pressures. They often consist of three or more fused benzene rings that contain only

one carbon and hydrogen (hydrocarbon) (ATSDR 2009). These contaminants are found within urban

settings on asphalt that has a coal-tar based pavement sealcoat or residue from engine combustion from

vehicles that end up leaking onto the parking lot ground surfaces (Mahler 2005). During rainfall events

within an area of high amounts impermeable surface, such as Unity College, contaminants within the

water run off the surface and accumulate as the water moves towards lower elevations. Accumulating

chemicals from urbanized landscapes proceed to flowing from the cities onto permeable surfaces, into

groundwater, and making its way to surface water, furthering the range of contamination, posing a

threat to environmental quality and ecosystem health.

Project Learning Objectives

1) To improve upon research skills, specifically in regard to environmental monitoring and data

modeling

2) Independently manage the sampling and analysis aspect of this project, work with other

students and set up a sampling timeline for the semester and ensure data is collected on

specified days

Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

3) Communicate findings via a presentation to the community at the conclusion of Spring 2019

Semester

Research Objectives

1) Evaluate the water quality of campus runoff from the parking lot at the top of the campus hill to

the bottom culvert that empties into the retention pond. Testing the retention pond is also

included as part of the data collection site reach.

2) Analyze the results of hydrocarbon concentrations from each sample and compare the data to

the other sites in this project

3) Compare results with scholarly sources to ensure my research results distinguish valid

information and proper protocol for collection

Materials and methods

Testing

Conductivity (Conductivity probe)

Turbidity (Turbidity meter)

PAH’s (Cyclops)

o Hydrocarbon concentrations based on parts per billion

Equipment

Conductivity Probe

Turbidity Meter

Cyclops (PTSA probe connection)

250 ml Sample bottles

250 ml Beakers

Rope (to drop a sample bottle down the grate to collect water)

Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

Sampling Methodology

Sample location codes:

o Culvert C05 – located at the bottom of Quaker Hill and it is the last culvert that flow

comes into before expelling into the retention pond

o CLC Culvert – the last culvert on the CLC side of the inner campus road (Murdock drive)

where the water goes into the culvert to pass under this pedestrian only road

o Gym Grate – a large grate located on the Eastern corner of the Athletic building, on the

edge of the parking lot and next to Loop road

o Library Culvert – this culvert is surrounded by pavement and is an inflowing culvert. The

culvert passes under the walkway that leads to the library

Figure 1: This map shows the distribution of the Grates and Culverts on the Unity College Campus. There were 3 culverts and 1 grate used for sampling in this study; indicated by a white circle on the map. Note that the retention pond is the lowest point to which campus runoff will flow from the highest point on campus (Unity Soccer Field) and it indicated with a circle and a label on the map.

Retention Basin

Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

Sampling

Precision: Take 3 readings within one collected sample to ensure standard deviation and error in

the instrument is minimal

Samples taken using 250 mL plastic sample bottles; site-flow water was flushed from the bottle

three times before final sample was collected to ensure minimal contamination from the bottle

is collected with the sample

Gym grate sampled were taken by tying a rope to a sample bottle and lowering it into the water

within the grate, allowing it to fill completely with water before drawing it back up through the

grate

Sampling time-frame

Rainfall events produce runoff to allow for sampling (runoff sampling is especially important at

the tail end of snow melt in April)

Sampling occurs peak of the rainstorm (optimal runoff when the storm produces the most

intense rainfall (rainfall per hour is highest within the storm)).

Results

Hydrocarbon concentrations were detected within all runoff samples (Figures 2 and 3) through

the sampling protocols carried out in this study. The highest concentrations of Hydrocarbons occurred

from the water flow going into culvert C05; the last culvert to bring water into the retention basin from

Unity College Campus (Figure 2). The retention Basin did have Hydrocarbons present within the water,

providing concentration comparable to that of the culvert at the base of Quaker Hill (C05) and

representing the second highest concentrations recorded for the study. The lowest concentrations were

detected in the Gym Grate and the culvert by the Library (Figure 3). As expected, all sample

concentrations were higher during rainfall events where more runoff was produced (Figure 2).

Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

Figure 2: Representing sample collection data for hydrocarbons through time at each different site. Concentrations

tended to increase with increased rainfall. More hydrocarbon concentrations were detected within the C05 culvert

than the others, except for the one isolated point detected from the CLC culvert on March 22, 2019 where the

concentration was very high; ~100 ppb. Concentrations of hydrocarbons were seen to not be directly related to

rainfall quantity. The highest concentrations detected within the samples was on March 31, 2019, when the rain

was only 0.31 inches, representing the second lowest rainfall event.

Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

Figure 3: The averages of all hydrocarbon concentrations per site are distinguished in the graph above. Note that

even though the Gym grate is surrounded by pavement and influence from combustion engines, it distinguished the

lowest hydrocarbon concentration levels. The C05 and retention basin have the highest; areas where majority of

water accumulates

Alongside hydrocarbon concentration testing with the cyclops, turbidity and conductivity were

also measured. The turbidity results were not representative of water contamination due to the

variability of water flow, rainfall amounts, and surfaces to which water passed over. Turbidity is the

measure of the relative clarity of a fluid, in this case, campus runoff. It is an expression of the amount of

light that is scattered by material in the water when a light is shined through the water sample. The

higher the intensity of scattered light, the higher the turbidity. Since each storm produced various

amounts of runoff and the conditions of the culverts, grates and ditches during this early spring,

muddy/snowy conditions, the turbidity was much too varied to show any significance in representing

overall quality of the runoff.

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

62.4

20.75

59.0

37.5

57.6

Hydrocarbon Concentrations Average at Each Site

C05 Gym Grate CLC Culvert Library Culvert Retention Basin

Hyd

roca

rbon

s (p

pb)

Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

Figure 4: Average Conductivity at each site. Notice how the CLC culvert and the culvert at the

most downhill point of the study reach (C05) have the highest conductivity, and they are actually equal.

Conductivity is the degree at which water will conduct electrical current, the Higher conductivity

values indicate there are more substances dissolved in the water. Data showed high and equal

concentrations of conductivity at the C05 and CLC culvert sampling sites (Figure 4). Accumulation of

dissolved minerals occurs as you move down slope, explaining why C05 culvert has high concentrations.

Though the explanation for the CLC Culvert having high concentrations as well is slightly unknown.

Discussion

0.0

0.1

0.2

0.3

0.4

0.3

0.045

0.3

0.1

Average Conductivity at Each Site

C05 Gym Grate CLC Culvert Library Culvert

Cond

uctiv

ity (m

S/cm

)

Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

Concentrations of hydrocarbons were surprisingly much lower in the Gym grate and Library

culvert samples than the other sites. Since they are of close proximity to parking lots, it was expected

that these two sites would have high levels of hydrocarbons since oil leaks from cars and a large,

impermeable surface area of paved landcover is present. Since the results show accumulation of

hydrocarbons in the trend following downslope of campus, the Gym grate and Library Culvert would

therefore be expected to have lower concentrations since little accumulation occurs here; it is mostly

washed away. It makes sense that the sites where a majority of the runoff from campus is collected

would have higher levels of contaminants since this represents the campus total concentration

accumulation; retention basin and culvert C05 (Figure 1). The high concentration value detected at the

CLC culvert on March 22, 2019 could be due pooling caused by leaf litter build-up. This could have led to

some concentrations to have accumulated more readily in this area during that time.

PAH concentrations of 308,000 ppb or higher exposed to organisms for 10 days (short term

exposure) causes birth defects (EPA, 2008). The results of this research represent hydrocarbon

concentrations far below the unsafe limit described by the EPA. Low detections of hydrocarbons may

have been due to the cold temperatures and the fast movement of runoff. PAH’s also are Photosynthetic

and they thermal degradation, allowing them to become volatile over time. Fewer hydrocarbons within

retention basin may be due to delusion and large area to absorb UV exposure that would enhance

degradation

Concentrations of hydrocarbons were seen to not be directly related to rainfall quantity. The

highest concentrations detected within the samples was on March 31, 2019, when the rain was only

0.31 inches, representing the second lowest rainfall event. This could be due to the fact that there is a

significant lag time between when rainfall events begin and when runoff is generated. Since only the

peak of the rainfall events were sampled, optimal runoff might have been retrieved from the tail-end of

the rainfall events.

Conclusion

The runoff system on Unity College’s campus carries not only water, but trace amounts of

contaminants from crude oil resulted from pavement material, vehicle engine combustion leaks, etc. but

accumulation concentrations were detected far below the EPA limit. All water from campus runoff is

either absorbed into the soil in the drainage ditches or carried to the retention basin where the

hydrocarbons are diluted, exposed to UV rays from the suns exposure and allowed to break apart and

Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

degrade. It is important to note that Unity College runoff does not carry high levels of hydrocarbons; low

concentrations within the accumulation zone (retention basin) support the significance of low

concentrations. This provides confidence in saying that the campus runoff system and retention basin is

working as it should to dilute pollution and that Unity College at this point, does not need to worry

about substantial hydrocarbon contamination in surface water leaving campus. The lack of

contaminants could be due to a small campus occupancy, indicating that future monitoring is necessary

if there is an increase in student enrollment in the future which could result in the increase of

hydrocarbon concentrations.

The concentrations of PAHs increased as the water accumulated as it flowed down slope from

the top of the hill on campus to the bottom were the retention basin is. Concentrations also seemed to

be unrelated to conductivity and turbidity. This may have been due to the fact that the amount of water

moving through the system and its speed is dependent on rainfall quantity and snowmelt rates. Having

multiple variables to consider makes it difficult to create relationships between those variables unless

multiple variables seem to support the another consistently. Timing of sampling during the rainfall

events also could have caused results to be inconsistent to become relatable since the storms were so

unique and the timing of sampling was slightly different within each of those events as well; some

samples were taken at an assumed peak rainfall when later in the storm was the true peak.

Future work and Recommendations

It is unknown whether or not water leaches from the retention basin to Sandy Stream, which is

in close proximity to the basin. Future work could include implementing Rhodamine dye to trace runoff

contaminants from the retention pond to Sandy stream. Another component could be to also

incorporate soil sample collection to determine how much of the hydrocarbon concentrations are

retained in the soil and how much are transported to the stream. If there is a concern for contamination

on campus in the future, this study can be used to provide areas where sampling would occur since it

identifies the accumulation zones of campus runoff.

Resources

Campus Runoff Water Quality Assessment

Hopkins, Sierra Unity College SP2019

ATSDR. 2009. “Toxicity of Polycyclic Aromatic Hydrocarbons (PAHs): Literature Cited | ATSDR - Environmental Medicine & Environmental Health Education - CSEM.” July 1, 2009. https://www.atsdr.cdc.gov/csem/csem.asp?csem=13&po=17

Mahler, Barbara. 2005. “Parking Lot Sealcoat: An Unrecognized Source of Urban Polycyclic Aromatic Hydrocarbons.” https://www.fws.gov/southwest/es/Documents/R2ES/LitCited/4TX_Sal/Mahler_et_al_2005_parking_lot_sealcoat_PAHs.pdf.

EPA. (2008). Polycyclic Aromatic Hydrocarbons. Washington DC: United States Environmental Protection Agency. hyyps://archive.epa.gov/epawaste/hazard/wastemin/web/pdf/pahs.pdf