Franklin Wastewater Treatment Facility

On Tuesday February 19th, 2019, I, along with the rest of my AP Environmental Science class, braved the windy and conditions to visit the wastewater treatment plant in Franklin, New Hampshire. At the plant, two employees, Art and Ken, explained the water treatment process and took us to several locations around the plant.

Control Screen (Photo by Ben Charleston)

Our first stop was the control room. The control room contains many computers which notify employees which systems are currently active, and an alarm will sound if one of the systems fail. Ken explained that each evening one employee is responsible for taking home a computer that is connect to the plant that will alert them if there is a problem that occurs after hours. This computer provides an alert that can prevent many costly the issues and fix problems promptly. Ken said that most of the time “you can resolve the problems right from your house, and you rarely ever have to come in to fix it” (Ken). However, fixing a problem was not always this convenient. Prior to computers and the systems beginning automated, employees had to come to the plant at all hours if there was a problem.

Our next stop was the preliminary treatment facility. At this location, the wastewater gets passed through a grit chamber and screen bars to ensure there are no large pieces of garbage mixed in with the wastewater. The solids that are removed during the preliminary treatment phase are immediately sent to a sanitary landfill. A sanitary landfill is a landfill lined with plastic and compacted clay to prevent toxins from leaching through which could contaminate groundwater.

Primary Treatment Tank (Photo by Ben Charleston)

Next, we visited primary treatment tank. The primary treatment tank consists of an arm which has both a bottom scraper and a top skimmer. The bottom scraper moves all of the settleable (sinkable) solids to the bottom of the tank, creating sludge. THis sludge is sent to the sludge digesters to produce methane gas. The top skimmer removes all of the floatable solids from the wastewater. The most common floatable is greases, however, settleables are more variable.

Aeration Tanks (Photo by Ben Charleston)

Following the wastewater, we walked over to the aeration tanks. Here, air is introduced into the wastewater so that microorganisms(bacteria), or as Art called them “bugs”, can remove the organic material from the wastewater. Art remarked, “Ken and I like to think of ourselves as ranchers because we have to maintain the right amount of bugs in the tanks” (Art). It is important that there are enough bugs in the tank to break down the organic material in a timely fashion. To adjust the amount of bugs in the aeration tanks, Ken and Art adjust the amount of activated sludge that is being reintroduced to the wastewater. If there is a shortage of microorganisms, more activated sludge will be introduced, and if there are too many microorganisms, less activated sludge will be introduced. In order to determine this information, a sample of these microorganisms is sent the a lab where they can tell what types and how many microorganisms there are in the aeration tanks. This information is then compared to how much food, also known as wastewater, that is entering the aeration tanks. The Biochemical Oxygen Demand (BOD) is also calculated to monitor the amount of oxygen being used by the microorganisms in the wastewater. If the oxygen demand is high, this could mean there is still a large amount of organic matter in the wastewater. If these values are high, then more microorganisms would need to added in order to break down the excess organic matter. After the organic contents of the wastewater are removed to an acceptable level, the water then goes to the secondary treatment tanks.

Sample of microorganisms (Photo by Ben Charleston)

The secondary treatment tanks have a similar design as the primary treatment tanks with the bottom scraper and top skimmer. Most of the solids removed during secondary treatment are a result of the microorganism activity in the aeration tanks. Some of the sludge created in the secondary treatment tanks goes back into the aeration tanks in the form of activated sludge, and the rest goes to the sludge digester where it can be utilized to produce methane gas. After all the solids are removed from the wastewater, the next stop is disinfection.

Disinfection facility (Photo by Ben Charleston)

To disinfect the wastewater, is travels through a pathway that contains ultraviolet (UV) light. The UV light scrambles the DNA of any organisms living in the water, making unable to reproduce. In the past, the plant has used chlorine to treat the water, however, using chlorine was controversial because of its possible negative health effects such as skin irritation, eye irritation, and more. While Chlorine is no longer used, it is kept at the plant in case of an emergency where the UV system fails.

Water being released into the Merrimack River (Photo by Ben Charleston)

After the water is disinfected, it is ready to be released back into the Merrimack River. As Ken said “While the water is not 100% clean we usually get it 93% clean which is sometimes cleaner than the river” (Ken). After we saw the water being released into the river, we went to the sludge digester where both the primary and secondary sludge is sent.

Sludge Digester (Photo by Ben Charleston)

The purpose of the sludge digesters is to anaerobically digest the sludge, a process which releases methane gas. The plant then uses the methane gas to heat its buildings and make hot water. This is a great example of an renewable energy source, and helps reduce the carbon footprint of the facility. After the sludge is digested, the leftover biosolids are then sold to farmers to grow crops for livestock – NOT for humans to eat. However, these biosolids could contain compounds, such as antibiotics, prescription drugs, and other chemicals, that do not break down. While there is limited research on the topic, contaminating soil with antibiotics and prescription drugs cannot positively impact human health. One way to avoid this would be to remove these chemicals from the biosolids before it is sold to farmers. However, this would probably be a costly endeavor, and no wastewater treatment facility would ever make such a large investment until it was required by law.

In my opinion, this trip was the most informative and relevant trip we went on all year. It is important for all of us to know where our waste goes after we flush, and this experience made me realize that when I flush, my waste does not just disappear. Instead, my waste enters a facility where it is cleaned and then returned to the environment. I was very surprised by how much water actually flowed through the plant every day. I thought the plant might treat a couple thousand gallons a day, but I was blown away when I heard the number was in the millions. Also, the plant did not smell nearly as bad as I expected. While there were times when it smelled pretty bad, it was very manageable for me. Before visiting the wastewater treatment facility I thought they just filtered out the solids, then disinfected it, and then dumped it back into the river. I never expected that the system would involve calculating the amount of microorganisms and the anaerobic digestion of sludge to produce methane gas. However, while most of the process was exciting, I was a little concerned when Ken said they sold the biosolids to farmers. Our waste is filled with chemicals, and, even though we do not directly eat the crops grown using biosolids, it is possible that the chemicals could make it back into our bodies. However, at this moment, there are not many studies on the use of biosolids on cropland, so it is not possible to know if the chemicals in our waste can make it back into our bodies. Overall, I enjoyed my trip to the wastewater treatment plant, as it helped me gain perspective and raised important questions which I look forward to exploring.


Visiting the Transfer Station

On February 16th, 2019 at noon, Alan drove myself and two other students to the transfer station in Andover, New Hampshire. The majority of my class went to the transfer station on February 2nd, however, I was at a ski race and I was unable to attend. The purpose of our visit to the transfer station was to see how the waste is sorted and disposed of.

At the transfer station, waste is sorted into two main categories: trash and recycling. Trash, the stuff that cannot be recovered, is placed into a compacted where it is compacted into a large container and then shipped out.

Photo taken By Ben Charleston

This trash could either end up being incinerated or placed in a sanitary landfill. Both of these options are are viable, however, a sanitary landfill takes up a large amount of space which is not available in some places, such as cities. Also, as Alan said “Most towns have contracts with the incinerator, and they have to send a certain amount of trash to be burned” (Alan McIntyre). This is problematic because it does not promote creating less trash, and these contracts rely on people throwing away a lot of stuff.

Recyclables, however, are items that can be reclaimed. At the transfer station, we saw many different categories of recycling. We saw plastic, glass, aluminium, tin cans, and even a station where people could leave there unwanted (but still functioning) items.

Photo Taken By Ben Charleston

Photo Taken By Ben Charleston

Photo Taken By Ben Charleston

Photo Taken By Ben Charleston

Photo Taken By Ben Charleston

Photo Taken By Ben Charleston

Some of the items at this station were old books and records for a record player. Employee Geoff Sweet explained that they get some money back for recycling materials, and no money back for trash. This is why it is both environmentally and economically responsible for people to recycle viable items.

Over the past few years there has been a huge push to promote recycling in response to the growing problem of waste disposal. However, despite this push, Geoff Sweet says that people with sometimes put recyclable items in trash bags, and then throw them in the garbage compactor out of pure laziness.

The last station was the electronic waste station. These items were unique because they contained mercury, and were considered to be toxic waste. These products cannot be thrown in a landfill or burned in an incinerator because, during this process, humans could be exposed to the mercury, which could lead to cancer or other health problems.

Photo Taken By Ben Charleston

Photo Taken By Ben Charleston

Geoff Sweet states that the transfer station does not have the necessary tools to dispose of toxic waste, and any hazardous waste , “items with a skull on them” (Geoff Sweet), must be processed at a different location. Although, Geoff admits that when people throw black garbage bags into the trash compactor, “there is no way for us to know what is inside” (Geoff Sweet). Therefore, it is possible that people could put toxic waste in the bags without anyone knowing until it is too late.

I really enjoyed going to the transfer station in Andover. I had been to the transfer station in my town, Belmont, New Hampshire, but I only looked around for a couple of minutes. It was cool to see all the different elements of waste disposal, and it was powerful to see how many things people were throwing away. When we first arrived, the trash compactor was completely empty, however, when we left fifteen minutes later, it was completely full. Also, there were many people who just threw away trash and recycled nothing. To me this is problematic from both an environment and economical perspective. Trash hurts our wallets and the environment far more than recycling does, and if everyone recycled, our world would be a better, cleaner place. Before visiting the transfer station, I was pretty unsure what it was. I thought it was something like a dump or a landfill. I now know that a transfer station is an important middle man that sorts the waste before it is brought to a sanitary landfill or an incinerator.

Personal Solid Waste Inventory

Starting February 7th and continuing until February 12th, I collected every piece of solid waste that I produced with the exception of food and dirty toilet paper. The purpose of this task is to realize how much solid waste I produce, and compare it to national averages. Also, through this assignment, I was able to realize that much of the trash I produce can be avoided using several techniques such as buying in bulk.

Photo Taken By Ben Charleston

For me, completing this assignment was especially difficult because I was not in class, and I was living in a hotel room and skiing at Jackson Hole in Wyoming. My absence from the class prevented me from weighing my garbage, and therefore I have no data on the weight of my trash in the data table.

Unfortunately, since I was not in class I was unable to observe everyone’s trash, however, one of my teammates in Wyoming also collected their trash, so I compared my data with his. I found that the most common item for both of us was plastics. Although we both produced a lot of plastic waste, his waste mostly came from contact lense cases and bar wrappers whereas the majority of mine came solely from food packaging.

I found that I produced much more trash while away from home because I was eating a lot of packaged foods and foods that were individually wrapped. If I repeated this assignment while living at home, I believe I would produce much less trash because I would eat foods that are not individually wrapped.

One negative effect of plastics on the environment is the process by which it is made. Two of the ingredients used to make plastic are crude oil and natural gas. Both crude oil and natural gas non-renewable resources, meaning once they run out, they are gone forever. In today’s world where fossil fuels are overused, it is environmentally irresponsible to use crude oil and natural gas to made a product that will be used once, and then thrown away. Another impact that plastic has on the environment is that plastics do not go away. Once plastics are in the environment, they are there forever. This buildup of plastic is causing plastic to bioaccumulate in organisms, particularly fish, which leads to biomagnification which affects human health. Lastly, another way plastics affect humans is by exposing humans to bisphenol A (BPA). When plastics are heated, the BPA stored in the plastic can leach out of the plastic and into the water of a plastic water bottle. This is problematic because BPA is a known carcinogen and endocrine disruptor. Recently, plastics are being made without BPA, however, it is still relatively unknown whether or not the chemical that replaced BPA poses a risk to human health.

If my parents did this assignment, I think they would produce about the same amount of plastic, paperboard, glass, mixed metals, and styrofoam as I did, but they would produce a lot more paper because both of my parents are teachers. I spoke with my parents, and they agreed with my observation. They explained to me that sometimes they go to print out a two paged test for twenty students, only to realize that there was a mistake, forcing them to reprint the entire test. Also, my dad drinks canned soda, and told me “I would have produced a lot more cans than you did” so if he did this assignment, his amount of aluminium waste would be greater than mine.

During this assignment, I did not alter my choices about what foods I ate. In fact, I ate more packaged food than I normally do because I was away from home. When I am on the road, I bring a lot of food with me because snacks are not always readily available. Most of these foods are individually wrapped such as protein bars, airheads, starburst, etc. My restricted access to food forced me into eating for individually wrapped foods than I normally would, which caused me to produce more trash. However, if I did this assignment when I was home, I would not have changed what I eat for this assignment because I am curious to know how much trash I produce living my current lifestyle. I now know that when I am traveling, I produce more trash than I would like to, and I will work to change that on future trips.

One aspect of this assignment that was significant was discovering that individually wrapped foods create most of my trash. Over 75% of my trash came from individually wrapped products. This made me realize that eliminating individually wrapped products would drastically reduce the amount of plastic waste the I produce. Also, for me to see the amount of trash that I produced in only six days was surprising to me. Going into this assignment, I knew that I produced a lot of trapsh, but I was not expecting to have 117 pieces of trash after only six days

If I changed something about the assignment, I would try to find a way to account for food waste because I think that food waste is both the most common and most dense type of waste. I know that carrying around your food waste is not realistic, but maybe you could keep a scale in the dining hall and after meals students could bag up their food waste and weigh it.


Photo Taken By Ben Charleston

Photo By Ben Charleston

How Can Bacteria Clean Up Toxic Waste?

Sitting in my house at 6:00 PM on Tuesday January 22, 2019, I watched a TED talk called “How Bacteria Talk” by Bonnie Bassler. Bonnie leads a research group at Princeton University in Princeton, New Jersey dedicated to figuring out how bacteria function and communicate. As she puts it “all of these people are between twenty and thirty years old” (Bonnie Bassler).

Photo of Bonnie’s research group at Princeton. Photo from the TED talk “How Bacteria Talk” by Bonnie Bassler.

The group discovered that bacteria can communicate through a process called quorum sensing, and initiate an appropriate response when enough bacteria are present. The group’s findings can reduce the amount of time it takes for a toxic waste site to be restored through the process of bioremediation.

This is a photo of a bacteria cell. Photo from the TED talk “How Bacteria Talk” by Bonnie Bassler.

What Is Quorum Sensing?

Quorum sensing is a form of communication that bacteria employ to find out how many other bacterium there are in the area. This form of communication is both an intraspecies and interspecies form of bacteria communication.During this process “it’s almost as if they are talking with chemical words” (Bonnie Bassler) by releasing a molecule into the surrounding environment. As Bonnie said, “When it [the bacterial cell] is alone, it does not make any light, but what it does do is make and secrete small molecules” (Bonnie Bassler). Here, Bonnie is explaining that the bacteria produce and secrete signal molecules to alert other bacteria of their presence. The bacteria also have receptors which bind with the secreted molecule and alert the bacteria that there are other individuals nearby. As the bacteria perform binary fission and increase in population, the concentration of the signal molecule increases as well. The more signal molecules there are, the more the receptors on the bacteria bond with the molecule and alert the bacteria that there are others present. Then, once the bacteria have determined that their population is large enough, they emit their response. Explaining her results from an experiment which studied light producing bacteria, Bonnie sated, “When the bacteria were alone, they made no light, but when they grew to a certain cell number, all the bacteria turned on light simultaneously” (Bonnie Bassler). In this situation, the bacteria were releasing light, but the response can be anything ranging from creating light to releasing a deadly virus.

Photo of light producing bacteria emitting their response. Photo from the TED talk “How Bacteria Talk” by Bonnie Bassler.

In nature, this phenomena can be observed in the Hawaiian Bobtail Squid. The squid uses the bacteria as a light source to hunt at night. Bonnie and her team found that they can both inhibit and induce the response of the bacteria. They can inhibit the response by introducing a molecule, similar to the signal molecule, into the environment. This mimicking molecule will jam the receptors on the bacteria and prevent them from releasing harmful chemicals. However, the team found that they can also induce the response of the bacteria by releasing the exact signal molecule into the environment, allowing for a more rapid response. This would be applicable to increase the rate of bioremediation.

What is remediation and bioremediation?

Remediation is the cleaning of toxic waste sites. Traditionally this has been done by simply digging up the toxic soil and moving it to a different location. However, in addition to being very costly, this method produced many health hazards such as airborne exposure and possible groundwater contamination. Also, even after all the soil is gone, it is hard to be sure that all of the toxic substance is eradicated from the soil. Bioremediation solves these problems and presents a way to clean up toxic waste in a cost effective manner. Bioremediation uses organisms, such as bacteria, to clean up a toxic waste site. However, the one problem with this method is that it takes decades to complete because normally the area is large and it takes a long time for a small organism like bacteria to populate the entire site.

How can Bonnie’s Research help?

Bonnie’s findings regarding quorum sensing can drastically reduce the amount of time it takes for a toxic waste site to be reformed through bioremediation. When the bacteria are cleaning up the toxic waste site, the bacteria “talk” to each other through intra and intermolecular signal molecules in order to initiate a response. We can increase the efficiency of communication between the bacteria by introducing more of the signal molecule into the environment. This will make the bacteria think there are a lot of other bacteria around, and it will initiate its response, and begin to clean up the toxins in the soil. In addition to adding more of the signal molecule, we can also add more food for the bacteria. This will allow the bacteria to reproduce faster, resulting in more bacteria working to break down and clean up the toxic waste. One place where this method could have helped is in Love Canal located near Niagara Falls in upstate New York. Love Canal was contaminated by tons of toxic waste buried underground. The effects from this disaster persisted for nearly 30 years before the site was able to be cleaned up. In this situation, if bacteria, the signaling molecules, and food for the bacteria were added, the site could have been cleaned up better and more efficiently.


Through the TED talk by Bonnie Bassler, I learned a lot about the way bacteria interact and communicate with each other and the positive or negative impacts on many topics, including human health and cleaning up toxic waste sites. Throughout the talk, while Bonnie was not directly talking about cleaning up toxic waste, I found everything she discussed very applicable to the principles of remediation which we have been studying in class. I learned about quorum sensing last year in AP Biology, however, before watching this video I never made the connection that the principles behind quorum sensing can be employed to expedite the process of bioremediation.

Personally, I really enjoyed watching this TED talk and thinking about how its principles can be applied to toxic waste clean up. I really enjoy taking concepts and trying to apply them to what I have learned in class. To me, the ability to apply something to another topic that seems unrelated is how advances and ideas are discovered, especially in medicine. Also, my favorite subject in school is biology, so the discussion of biological principles such as quorum sensing and gene activation were very intriguing for me. Overall, this experience was very enjoyable for me, and I hope to find similar problem solving challenges in the future.

Work Cited

Bassler, B. (2009). How bacteria “talk”. Retrieved February 01, 2019, from

Miller, M., & Bassler, B. (n.d.). Quorum sensing in bacteria. Retrieved January 31, 2019, from

The Hunt for PBDEs

Ben Charleston

January 14th, 2019

The Hunt for PBDEs in both the Day Student Lounge (DSL) at Proctor Academy, and my home in Belmont, New Hampshire

Results for the Day Student Lounge:

Results for my house:

Examples of products and their tags that contain PBDEs:















Examples of products and their tags that do not contain PBDEs:













Concluding Questions:

A) Where (what kind of room) did you find most of the (PBDE) flame retardant products?

I found most of the flame retardant products in my living room. I think this is because my living room contains a lot of furniture from before 2008, and it was made when TB-117 still required flame retardants. In the more modern rooms of my house, such as my bedroom, I found fewer items that contained flame retardants


B) What was the most abundant product found to be dosed in flame retardants?

The most abundant product found to be dosed in flame retardants were couches and chairs. While most of these products that I found at Proctor in the Day Student Lounge were flame-retardant free, nearly all the couches and chairs in my house were doused in PBDEs.


C) Examining your charts, which product do think gets the most use from people?

Examining my charts, I believe the product that gets the most use from people is mattresses. While couches are also heavily used, I typically lay on my mattress for a minimum of 8-10 hours per day, while I only sit on couches for a couple of hours. I think many other people in America also use their mattress far more than any other piece of furniture.


D) Knowing that exposure rate, route of exposure and age of exposure are keys to determining the toxic impact, which product generates the highest health risk? Which product has the lowest health risk? Explain why.

I think that mattresses generate the highest health risk because people are exposed to their mattresses every night. Since one’s head is only inches from the mattress while sleeping, the route of exposure is inhalation. When something is inhaled, it can reach the bloodstream in a matter of seconds. Also, since young people sleep longer, they are exposed to the toxins in their mattresses for an extended period of time. This is dangerous because children under the age of six have an extremely fast metabolism, and the chemical can be absorbed into the body with ease. I think the rug under my Christmas tree at my house has the lowest health risk for two reasons. One is because it is only present in my living room for three months of the year, meaning that the exposure rate is very low. The second reason is because the rug is on the floor, it is unlikely that people will be inhaling the PBDEs from the carpet unless they are laying on the floor, which is an uncommon occurrence.


E) After watching TOXIC HOT SEAT what would you suggest are some appropriate means to address the concerns of PBDE exposure?

Educating the public, especially parents, about what PBDEs are and the possible risks associated with them could prevent people from buying furniture with PBDEs in it. In addition, I would suggest better labeling of furniture. When I was searching for these labels at home and at Proctor, the labels were hidden in obscure places which made the very hard to locate. Then, once I located the tag, it was challenging for me to tell whether or not the product contained flame retardants. I think every piece of furniture should explicitly state whether or not it contains PBDEs or not. Also, I know it is hard to test the effects of chronic exposure to a chemical, but I think the scientific community needs to make a considerable effort to identify specific diseases associated with PBDEs and attempt to find ways to prevent and maybe even cure those diseases. One of the major problems put forth in the movie was that the scientific community was not speaking up about the dangers of PBDEs, and this must change if we ever want to live in a world that is free of flame retardants.


F) Reflect on the movie, this activity and what you have learned. Share your thoughts, concerns, and impressions.

My biggest concern after watching the movie and doing the activity is that it is tough to tell whether or not a product contains PBDEs. When I looked at the tags, I knew exactly what I was looking for, and sometimes I still could not figure it out. This makes me wonder if the average consumer, who probably knows very little about TB-117 or flame retardants would be knowledgeable enough to decipher whether or not a product had PBDEs. I am also concerned about the effects that PBDEs will have on the people who were exposed to them, especially at a young age. For me, this concern is personal because when flame retardants started to become popular. I grew up surrounded by flame retardants, and no science explains the health problems I could face later in life due to my exposure to PBDEs as a child. Lastly, I am concerned that even though we are starting to phase out PBDEs, they will never become completely eradicated from the environment. This could lead to adverse health due to PBDEs for many generations to come.



Proctor Pond Final Blog Post


The purpose of studying the pond is “to understand if the pond is healthy or not by measuring biodiversity”(Alan McIntyre). It is important to study the pond because the recent addition of the artificial turf fields could disrupt the biotic and abiotic interdependence within the pond. As Alan stated, “Artificial turf may create an artificial die-off” (Alan McIntyre). Also, the data collected will be important because the pond is being dredged in December, and the data from this year can be compared to the data from next year and determine whether or not dredging improved pond health. On the dates October 19th, October 23rd, and October 25th, E Block AP Environmental science investigated and gathered data on the Proctor Pond.


The pond should be healthy with significant biodiversity because it is located in a protected area away from anything environmentally hazardous or threatening. Even though the turf fields are within proximity, drains divert water from the turf away from the pond.


  • 1 Thermometer to test both the air and water temperature
  • 1 D-shaped net for collecting biotic samples
  • 1 iPhone 7 for taking pictures
  • 1 notebook for recording biotic and abiotic data, as well as making general observations about the site
  • 1 pencil to take notes
  • 1 Beaufort scale to identify the wind speed based on observations
  • 2 test tubes, each with 5 mL and 10 mL markings on them
  • 1 LaMotte phosphorus testing kit
  • 1 LaMotte pH testing kit
  • 1 LaMotte turbidity testing kit
  • 1 large bin for collecting samples
  • 1 small container with three compartments for identifying specific organisms
  • 1 magnifying glass
  • 1 pipette
  • 1 Spoon with holes in it
  • 1 biotic identification sheet for identifying indicator species, somewhat tolerant species, and very tolerant species.

Photo by Sarah Ferdinand

Sampling Methods:

Each day, Will Luskey, Joey Briggs, and I collected data using the same method. First, we collected biotic samples and then abiotic samples. Below is a procedure for collecting both biotic and abiotic samples.

Biotic Sampling:

  1. Pick up the D-shaped net, the large bin, and the small container and bring them over to the edge of the pond.
  2. While standing at the edge of the pond, place the D-shaped net into the water, and make sure it is touching the bottom.
  3. Next, move the net to the right, and then back to the left (this is called sweep netting) three times. At this point, the net should have an inch or two of abiotic material in it.
  4. Next, place the contents of the net into the large bin, and then fill the large bin halfway with water from the pond. Remove the large pieces of organic matter which will impede your vision (leaves or sticks), but leave the organic material that will not impede your vision (dead grasses) as they could be a home for an organism.
  5. Now, begin to sift through the contents of the bin and place any living organisms into the smaller container, where they can be identified. Begin to identify these organisms using the biotic identification sheet. Record the quantity of each species found in a notebook. (NOTE: WE DID THIS INSIDE ON OCTOBER 25TH SINCE IT WAS TOO COLD OUTSIDE)
  6. Repeat steps 1-5 as time permits
Original photo by Ben Charleston
Original photo by Ben Charleston

Abiotic Sampling:

  • Air temperature:
    • Hold the thermometer with an outstretched arm, and make sure the probe is not touching the ground. Observe the thermometer reading, and once the reading stays at one value for 60 seconds, record the air temperature in a notebook.
  • Water Temperature:
    • Place the probe into the water, ensuring it is completely submerged. Observe the thermometer reading, and once the reading remains at one value for 60 seconds, record the water temperature in a notebook.
  • Phosphate:
    • Fill one of the test tubes with pond water up to the 5mL line.
    • Take one of the tablets from the phosphate test kit and place it in the test tube, and shake the test tube until the tablet is completely dissolved.
    • Wait five minutes, and then compare the color of the solution in the test tube to the colors on the chart to get a numerical value (1-4) for the phosphate level.
Original photo by Ben Charleston
Original photo by Ben Charleston
  • pH:
    • Fill one of the test tubes with pond water up to the 10mL line.
    • Take one of the tablets from the pH test kit and place it in the test tube, and shake the test tube until the tablet is completely dissolved.
    • Compare the color of the solution to the colors on the chart to get a numerical value (1-11) for the pH.
Original photo by Ben Charleston
Original photo by Ben Charleston
  • Wind Speed:
    • Examine the Beaufort scale chart, and compare the surroundings to the description on the chart to get a numerical value (1-12) for the approximate speed of the wind.

Original photo by Ben Charleston

Original photo by Ben Charleston
  • Turbidity:
    • Fill the test tube from the turbidity testing kit to the specified amount.
    • Place the test tube over the center circle and look through the test tube, at the circle.
    • Approximate the turbidity (0-100 JTU) by comparing the appearance of the circle beneath the test tube to the surrounding circles, with corresponding numerical values.
Original photo by Ben Charleston
Original photo by Ben Charleston


  • Weather:
    • Simply pay attention to the weather for the entirety of the study
    • Classify each day as sunny, partly cloudy, cloudy, rainy, or snowy. (Also, note if there is extremely high wind)

Narrative on Sites, Observations, and Events

On Friday, October 12th, 2018, the class was split up into five groups containing three to four students in each group. My group of three people was assigned data collection from site three. Site three is in the back right corner of the pond, as seen in the map below. Also, there are two inflows to the pond at sites one and two, and one outflow at site five. The water in the pond comes from all the drains around campus (see map below) going all the way back to the hockey rink. We studied our site at different times of the day, on each day of study. On October 19th, the site was studied from 10:55 AM to 11:25 AM, On October 23rd, the site was studied from 11:45 AM to 12:30 PM, and on October 25th, the site was studied from 10:40 AM to 11:20 AM. On the last two days of the study, October 23rd and 25th, the wind was light, and these days earned a one and two, respectively, on the Beaufort scale. This approximates to winds speeds of 1-3 mph on October 23rd and 4-7 mph on October 25th. However, on the first day of the study, October 19th, the wind was much stronger, and was evaluated at a 5 on the Beaufort scale. This is significantly stronger than the other two days, and approximates to 19-24 mph. Also, there was a major rain event between October 19th and October 23rd, which could have brought sediment into the pond and affected the data. Site three is unique because it is the only site on the pond which has a significant amount of grass. This grass is important because it protects the surrounding area from wind and debris. However, as the study went on, I began to notice that the grass was dying, and by October 25th, the grass was still standing, but was 100% brown with no traces of green. This rapid death of the grass could be due to the temperature and weather on the three days which was 53.2°F and partly cloudy on the 19th, 46.6°F and cloudy on the 23rd, and 39.5°F and partly on the 25th. Despite the cold temperatures and overcast skies, the quantity of organisms observed increased each day we sampled. On the first day ten organisms were observed representing four different species, on the second day 44 organisms representing 9 species were recorded, and on the third day 39 organisms representing 6 species were observed.

Original photo by Ben Charleston
Original photo by Ben Charleston
Map by Zach Raye Steiner, Will Luskey, and Joey Briggs
Map from Sarah Ferdinand, made by Anna Krajewski




Annual Water Temperature: Data table made by Ben Charleston, inspired by Sarah Ferdinand

Year Water Temperature (°F):

Year                                                                          Water Temperature (°F)

2007 52.1
2008 52.1
2009 N/A
2010 53.1
2011 N/A
2012 54.3
2013 55.6
2014 54.4
2015 50.5
2016 47
2017 56.6
2018 44.84
Overall Average 52.054

Dissolved Oxygen (mg/L) Over Time: Data table made by Ben Charleston, inspired by Sarah Ferdinand

Year Average (mg/L)
2007 2.5
2008 1.67
2009 N/A
2010 1.6
2011 N/A
2012 1.5
2013 N/A
2014 6.2-7.9
2015 6.65
2016 8.3
2017 1.39
2018 N/A
Graph by Ben Charleston, inspired by Sarah Ferdinand

This data set demonstrates that the water temperature this year is the coldest since 2007, 7.214°F below the average and 2.16°F colder than the next coldest year. The average air temperature during the study was also cold, measured at 45.9°F. The temperature of both the air and the water are important factors to consider. Colder water temperatures allow the water to hold more dissolved oxygen. Although the dissolved oxygen levels were not measured this year (due to technical failure of the DO measuring device), I would hypothesize that the DO levels this year are the highest of any year. This hypothesis is supported by the data because the next coldest year (2016) when the temperature was 47°F, the dissolved oxygen content was 8.3mg/L, higher than any other year. Also, the second coldest year, (2015) when it was 50.4°F, the dissolved oxygen content was 6.65mg/L, the second or third highest ever recorded. If this trend continues, than it is likely that this year had a dissolved oxygen content of at least 8.3mg/L. While dissolved oxygen is an important factor, it is clear that DO levels fluctuate more from temperature changes, than actual changes in the ecosystem’s health. For example, the study in 2007, when the temperature was 52.1°F, measured DO levels of 2.5mg/L, the fifth lowest ever, but a diversity index of 19.3 (See the data table below), the highest ever. This proves that while DO levels may represent changes in the ecosystem, scientists must be careful because DO levels are also a reflection of the temperature during the study.

Also, the cold air and water temperatures were a variable which prevented us from keeping our hands in the water for a long time. This could have prevented us from seeing some organisms which could possibly alter the data.

pH Over Time: Data table made by Ben Charleston, inspired by Sarah Ferdinand

Year Average
2007 6.77
2008 7.03
2009 NA
2010 6.88
2011 NA
2012 6.63
2013 7.25
2014 6.15
2015 6.42
2016 6.75
2017 6.68
2018 6.73
Overall Average 6.73

Mayfly Nymphs Over Time: Data Table Made By Ben Charleston

Year Number of Mayfly Nymphs observed
2007 11
2008 5
2009 N/A
2010 11
2011 N/A
2012 9
2013 30
2014 72
2015 7
2016 27
2017 24
2018 15
Overall Average 21.1

Stonefly Nymphs Over Time: Data Table Made By Ben Charleston

Year Number of Stonefly Nymphs observed
2007 5
2008 2
2009 N/A
2010 1
2011 N/A
2012 1
2013 22
2014 6
2015 2
2016 0
2017 6
2018 3
Overall Average 4.8
Graph by Ben Charleston, inspired by Sarah Ferdinand

This data is useful because Mayfly Nymphs and Stonefly Nymphs are indicator species, which means they require a very specific pH to survive. As Alan said, “Indicator species will not tolerate a pH less than 6.5 or greater than 7.5, or bad water quality” (Alan McIntyre). This proves that if there is an abundance of indicator species, the body of water is in good health. Throughout the years the pond has been studied, the year with the highest amount of stonefly nymphs and mayfly nymphs was 2013 when the pH was 7.25, the closest ever to neutral (7). In 2013, there were 22 stonefly nymphs and 30 mayfly nymphs observed. The almost neutral pH, and the abundance of mayfly nymphs and stonefly nymphs observed shows that the pond was in good health in 2013. One exception to this trend is the number of mayfly nymphs observed in 2014. In 2014 the pH was 6.15, too low for an abundance of indicator species, yet the class observed 72 mayflies. However, Alan explained that during this year, “There was one student who was exceptional at biotic sampling, and collected the vast majority of the organisms. I think this student had previous experience studying a body of water beforehand” (Alan McIntyre). Therefore, the reason for the high amount of mayfly nymphs in 2014 is not because the water quality was good, but rather because one student had experience with sampling, making this data hard to compare to other years.

Also, due to the cold temperatures, my group’s ability to identify mayflies and other smaller species was impaired. For example, on the third day, it was so cold that we were forced to go inside to do our biotic sampling, and on this day (October 25th) we found 7 mayfly nymphs compared to only 4 mayfly nymphs on the first two days combined. This supports the idea that if scientists are distracted (cold weather), the data can be impacted greatly.

Diversity Index: Data table by Ben Charleston, inspired by Sarah Ferdinand

Year Average
2007 19.3
2008 15.4
2009 N/A
2010 11.7
2011 N/A
2012 7.26
2013 12.2
2014 7.1
2015 6.3
2016 6.3
2017 7.4
2018 7.09
Overall Average 10
Graph by Ben Charleston, inspired by Sarah Ferdinand

This diversity index was calculated using the Simpson’s Diversity Index Formula:


In this equation, N is the total number of individuals, and n is the number of individuals observed from one species. This formula is designed to account for the richness and evenness of a species. This calculation is useful because the higher the number, the more species present. For example, in 2007, which recorded the highest diversity index ever, there were 25 different species observed. Also, in 2008, which recorded the second highest diversity index ever, there were 24 species present. However, in 2015 and 2016, the two lowest diversity indices ever, there were only 19 and 22 species observed. While this may seem like a lot, in 2015 only 10 of the species had more than 5 individuals observed, and in 2016 only 7 of the species had more than 5 individuals observed. Therefore, biodiversity isn’t only based on the pure number of species present, but also the how many individuals of each species are present.

Water Quality Pollution Index: Data table made by Ben Charleston, inspired by Sarah Ferdinand

Year Average
2007 59
2008 48
2009 N/A
2010 44.3
2011 N/A
2012 41.6
2013 66.4
2014 63.5
2015 37.9
2016 34.4
2017 48.1
2018 34.3
Overall Average 47.75
Graph by Ben Charleston, inspired by Sarah Ferdinand

The water quality pollution index was calculated by labeling each species as dominant (>100 organisms), common (10-99 organisms), and rare (1-9 organisms). After labeling each species, the species were split up into three categories with varying levels of pollution toleration. The species with low levels of pollution toleration, indicator species, were given more weight than species who cold tolerate higher levels of pollution. The values for each of the groups were then added up to get the water quality score. A water quality score of more than 40 signifies excellent water quality, a score of 30-40 signifies good water quality, a score of 15-30 signifies fair water quality, and a score less than 15 signifies poor water quality. Our water quality score was 34.3, meaning the pond water quality is good. This is the lowest water quality score ever recorded. However, the low water quality may not indicate that the pond is totally unhealthy, as the temperature could have affected this data. In 2016, the second coldest year ever recorded, the water quality pollution index was 34.4, only 0.1 higher than ours. Also, in 2017, the warmest year ever, the water pollution index was 48.1 which is significantly higher than this year, as well as the two previous years. Therefore, water temperature may decrease the water quality pollution index for two possible reasons: colder water decreases organisms’ activity, making them harder to catch, or the colder air and water temperatures make the scientists so uncomfortable that it becomes impossible to accurately identify all the organisms in the sample.

Turbidity (JTU): Data table by Ben Charleston, inspired by Sarah Ferdinand

Year Average (JTU)

























Overall Average


Graph by Ben Charleston, inspired by Sarah Ferdinand

This data and graph regarding the turbidity of the pond is useful because turbidity is indicative of how much sediment is in the water. While sediment can be harmful to a pond, it also brings in nutrients that promote population growth. For example, in 2013, the average turbidity was 20 JTU, the highest ever recorded. The high turbidity in 2013 can be attributed to the installation of the turf fields, which do not hold the sediment as well as the previous grass fields. However, in 2013, the in the diversity index went up from 7.26 in 2012 to 12.2 in 2013, and the water quality pollution index went up from 41.6 in 2012 to 66.4 in 2013. This trend is observed again in 2017 when the average turbidity was 13.3 JTU, and the diversity index was 7.4, which is 1.1 higher than the previous two years. The water quality pollution index was 48.1, significantly higher than in 2015 and 2016, which recorded water pollution indices of 37.9 and 34.4, respectively. Therefore, as the turbidity increases, the biodiversity and water quality increase as well.

Although turbidity increase water quality and biodiversity, high levels of turbidity are not a good sign for the pond. Higher turbidity levels mean there is an excess amount of sediment entering the pond, which means the pond is slowly getting shallower. This shallowing trend is one of the reasons why Proctor decided to dredge the pond in December.

One variable for collecting the turbidity is some groups did it before sweep netting, after sweep netting, or from their sampling bin. Taking the turbidity after sweep netting or from the sampling bin could give levels of turbidity that are too high because the benthic (bottom) region of the site had already been disturbed, which could make the water murky. Taking a sample for this murky water would give a turbidity reading that is higher than the actual turbidity at the site.

Phosphate (PPM): Data table by Ben Charleston, inspired by Sarah Ferdinand

Year Average (PPM)

























Overall Average


Graph by Ben Charleston, inspired by Sarah Ferdinand

The phosphate levels of the pond indicate how much ATP (Cellular Energy) is being produced through respiration by organisms in the pond. In a healthy system, the phosphate levels should be low because organisms are utilizing all phosphate for ATP production. This is reflected in the data from the pond, and years with high phosphate levels typically had lower biodiversity. For example, from 2007-2008, phosphate levels increased from 2.2PPM to 4.0PPM, and the diversity index decreased from 19.3 to 15.4. Also, the study in 2013 recorded phosphate levels of 0.4PPM, the lowest ever, and the diversity index of this year was 12.2, up 4.94 from the previous year. Therefore, the overall trend is that as phosphate levels decrease, biodiversity increases. However, in 2012, phosphate levels were low, but biodiversity was also low. The low diversity index in 2012 was not due to a lack of species, as 24 different species were observed, but it is because there were a handful of species which dominated the others in terms of individuals that were observed. This domination could be due to the construction happening in 2012, which could have put sediment in the pond that contained nutrients which favored the growth of only a few species.

This year, one possible source of error my group had is that we only measured phosphate levels for one out of the three days because our class ran out of tablets. This struggle was shared by many other groups, and could have impacted our classes overall average phosphate levels. Another variable in our study is that the phosphate levels were qualitatively measured on a color scale, and the interpretation of the color that signifies a certain value could vary from group to group. For example, our group approximated the phosphate levels as 1.5 because the color was in between one and two, but some groups only used whole numbers. This difference in the collection of data from group to group could have altered the data significantly.

Original photo by Ben Charleston


Throughout the study of the pond, there were many data points, both abiotic and biotic, that were observed or calculated. The reason for collecting this data is to determine the healthiness of the pond. Based off this year’s data, I would say that the pond is in decent, but declining health. I say this because the turbidity this year was 14.32 JTU, the second highest ever recorded. This means that there is a lot of sediment flowing into the pond from various places such as parking lots and construction sites. All of this sediment is slowly filling in the pond, and, as Alan said, “the pond has gotten significantly shallower over the years” (Alan McIntyre) and “Without dredging, it would turn into a wetland” (Alan McIntyre). Also, turbidity shows how deep sunlight can reach into the pond. If the sunlight can only reach a few feet below the surface, that means the compensation point of the pond is higher, making the pond less productive. The compensation point is the point where the amount of oxygen produced through photosynthesis is equal to the amount of oxygen required to perform cellular respiration. Essentially, the compensation point is the depth where the pond becomes productive, and the deeper the compensation point, the more productive the pond. Therefore, the fact that the turbidity was so high this year means that the compensation point of the pond is most likely shallow, meaning the pond is probably less productive than in previous years. Another concerning data point is the number of mayfly nymphs and stonefly nymphs observed. This year there were 15 mayfly nymphs compared to 24 in 2017, and there were 3 stonefly nymphs this year, compared to 6 in 2017. Indicator species are valuable because they have very specific niches, meaning they have very specific needs in order to survive. Since indicator species have very specific niches, if they are present in abundance, typically, the water quality is excellent. This year we found a total of 15 mayfly nymphs and 3 stonefly nymphs, which is a very low number and shows that the pond is in declining health. Also, the water quality pollution index was 34.3, the worst ever recorded, suggesting the pond is on a downward trajectory. However, there are two data points which show the pond is in decent health, phosphate levels and the diversity index. This year the diversity index was 7.09. Although this number is lower than last year (7.4), it is higher than the diversity index in 2015 (6.3) and 2016 (6.3). The diversity index from this year shows that the pond has, at most, lost a little of its biodiversity from last year. Also, the phosphate levels this year were 1.25 PPM, the fourth lowest ever, although phosphate was not measured in 2009, 2010, 2015, 2016, or 2017. Low phosphate levels are a good sign because it means that there are enough organisms respiring in the pond using the available phosphate to produce ATP (Adenosine Triphosphate).

Based off all of the data points collected, I conclude that the pond is mainanting decent health, but the health will continue to decline if nothing is changed. However, with the dredging of the pond this winter, I believe that the pond will recover. I think next year, the study will conclude that the pond is unhealthy, but in the years after that, the study of the pond will conclude the pond is healthy and yield similar result to the study in 2007 and 2008.

Despite the declining health of the pond, some symbiotic relationships were observed. One of these symbiotic relationships is predation between predaceous diving beetles and tadpoles. In this relationship, the predaceous diving beetle preys on tadpole populations. In addition to symbiotic relationships, competition between species was also witnessed. Since the pond does not have an unlimited amount of resources, there is competition for food. Two species that regularly compete over food are mayfly nymphs and stonefly nymphs. This competition is called interspecific competition. This competitive relationship is supported by the data because there is only one year, 2013, when there were a lot of mayfly nymphs and stonefly nymphs.

Although extensive measures were taken to ensure the accuracy of our study, there were many variables and possible sources of error. Of these variables, the ones that affected our study the most was the temperature, our method of biotic sampling, and the fact that some of the abiotic tests can be altered by interpretation. The cold air temperature, measured at 45.9℉, made it painful to keep my hands in the water for more than one minute at a time. This could have caused us to overlook many organisms that we would have seen in warmer conditions. However, on October 25th it was so cold that we had to do our biotic sampling inside. Sampling inside allowed my group to focus better, and therefore we found more organisms. Also, as the study progressed, picking organisms out of the bin became easier and easier. This suggests that many organisms could have gone undiscovered and unaccounted for on the first day. Another major variable was the fact that the measurements for phosphate, pH, and turbidity were all derived by comparing the color of a solution (or a circle for turbidity) to a chart. This is a source of error because each person may interpret the color differently, which could skew the data for the whole class.

When Alan first told us we were going to study the Proctor Pond, I was excited. During my sophomore year, I did a history project on the pond, so I know all of its history, but I have always wanted to know about its current health. Albeit, I must admit I was a bit nervous because I had no previous experience with biotic sampling or identifying species. However, after the first day, I immediately became comfortable with and enjoyed testing both the abiotic and biotic factors at my site. I learned how to sweep net and sift through the contents of our net and locate most of the living organisms. However, this study was not always easy, as it was extremely cold, windy, and, at times, rainy. Although I was able to push through these unfavorable weather conditions, I would like to do this study again when I don’t have to stick my hands under my armpits every five minutes to warm up my hands. All things considered, this study was fun, and every time I walk by the Proctor Pond, instead of staring at my phone, I will think about all the mayfly nymphs, scuds, copepods, and other species lurking below the surface.

Proctor Pond Study Post #1

Purpose: The purpose of studying the pond is “to understand if the pond is healthy or not by measuring biodiversity”(Alan McIntyre). It is important to study the pond because the recent addition of the artificial turf fields could disrupt the biotic and abiotic interdependence of the pond. As Alan stated, “Artificial turf may create an artificial die-off”. Also, the data collected will be important because the pond is being dredged in December, and the data from this year can be compared to the data from next year and determine whether or not dredging improved pond health.

Hypothesis: The pond should be healthy and have biodiversity because it is located in area that is protected and away from anything environmentally hazardous or threatening.  Even thought he turf fields are close, they have drains that divert water from going from the turf to the pond.

Materials: Thermometer, net, phosphorus testing tablet, pH indicator tablets, large bin for collecting samples, small container for identifying specific organisms, and a magnifying glass.

How to accomplish the study: Using the materials from above, we will examine and collect data on the abiotic and biotic factors of the pond for several class periods. Since all areas of the pond are different, the class was split up into groups to cover the whole pond. Each group was assigned a specific location on the pond, and at the end of the study, all the groups will combine their data to determine the health and resilience of the pond.

Method for Data Collection:  A net was placed in the pond near the edge and moved in a circular motion to stir up the bottom and collect small invertebrates. The invertebrates from the net were placed into a bin to examine the contents, identify organisms of special interest, and place those organisms into a separate container for further examination. The organisms of interest were examined to determine if they were indicator species (not tolerant to water pollution), somewhat tolerant to water pollution, or very tolerant to water pollution. After identifying these organisms, the pH and phosphorus levels of the water was tested using a pH and phosphorus test kit.

Observations: Upon arriving at the pond, I noticed that the lily pads and vegetation around the pond was beginning to die off. As Alan stated, “The vegetation will continue to die off every time the ground frosts over at night”. At my site,  in the corner of the pond with the most vegetation, I noticed that the tips grass in the pond were starting to turn brown, although the majority was still green. The air temperature at our site was 42.2°F , and the water temperature was 50.5°F. After measuring the temperature, a net used to collect biotic elements from the pond and begin identify organisms. In total 16 organisms identified from 7 different species.

The organisms we collected

Of the 16 organisms observed, only 3 were indicator species(all of them were mayfly nymphs), and the rest were tolerant of pollution to an extent. Next, the abiotic elements of the pond were analyzed. To test the pH of the pond, 10mL of water was placed in test tube, then a pH tablet was added and shook until the tablet was completely dissolved. The color of the water in the test tube was compared to a chart to determine the pH of the pond at our site. The pH of the pond was approximately 6.5, which is slightly acidic, as seen in the pictures below.

The scale to measure pH
The color of the pond water after adding the pH tablet

Next, the phosphorus levels of the water was tested by collecting 5mL of water in a test tube, then adding a tablet and shaking the solution until the tablet was dissolved. Also, it was necessary to wait five minutes after the tablet had dissolved to compare the color of the solution with the chart to determine the phosphorus levels. After five minutes, the color of the solution appeared to be between a 1 and a 2 on the phosphorus chart, as seen in the photos below.

The color of the pond water after adding the phosphorus indicating tablet
The scale to measure phosphorus levels












Location Air Temperature (Degrees Fahrenheit) Water Temperature (Degrees Fahrenheit)
Site #3 42.2 50.5


Abiotic Factors:

Element Measured Level Recorded
pH 6.5
Phosphorus 1-2


Biotic Factors:

Species Observed Number of Individuals observed
Mayfly Nymph 3
Scuds 5
Midge Larvae 2
Predaceous Diving Beetle 1
Damsel Nymph 1
Copepod 3
Backswimmer 1


The air temperature indicates that the vegetation inside and around the pond could soon be dead. A temperature of 42.2°F during the day means that temperatures are well below freezing at night, meaning the possibility of a frost or snow, which would kill the plants, is high.

The abiotic factors we recorded seem to indicate that the pond is healthy. A slightly acidic pH of 6.5 is almost neutral which means the pond can support a variety of species, leading to biodiversity. The phosphorus level in the pond are low, which means that nearly all the available phosphorus is being used by the organisms for energy in the form of ATP, which is “the energy for all living systems” (Alan McIntyre). Low levels of phosphorus in the water  indicate that there are many organisms in the pond, since almost all of the available energy is being used.

The biotic factors observed also support the conclusion that the pond is healthy. However, most of the organisms that were found are tolerant of pollution, indicating that the pond may be polluted a little bit, but not heavily. Test more location in the pond, for example locations much deeper and towards the middle may yield some different organisms.


Overall, the points of data that we collected today indicate that the pond is resilient and healthy. There is a wide variety of species in the pond, and these species are present in abundance. However, one point of data that could be incorrect is the temperature of the water. When I measured the temperature of the water I did so in only a couple inches below the surface, and the temperature in deeper water could have been different.

I really enjoyed the first day studying the pond. It was fun to catch and identify species on our own. After the watershed project I was familiar with the names of the invertebrates. I also enjoyed testing the abiotic factors, and I look forward to testing another abiotic factor in the future: nitrate levels. Having quantitative data of different components in the pond provides insight to factors that contribute to pond health. Testing the level of nitrates suggest how many amino acids are present in the pond. Ideally, in a healthy ecosystem, there should be no free nitrates, and all the nitrates will be used by organisms to synthesize proteins. Based on the data I collected today, I anticipate that the nitrate level of the pond is low, as the other tests have indicated the pond is in good health.