HUB IN THE SPOTLIGHT: Haileybury || Making River Action Part of the School Day

SS:  Wednesday afternoons are ringfenced for students to participate in activities of their choice. There’s lots to choose from: some students are working on building a satellite, others are looking into fruit fly genetics. The Community Action and Volunteering Group is one of the activities they can sign up for at the beginning of each school year. Within this Group, we have a rotating roster of socially and environmentally engaged projects: some days we go down to a garden allotment in the village, other days we spend time at a care home, other days we learn sign language. 

On our Drinkable Rivers days, we hop on a minibus and head down to the river at Hertford’s Hartham Common, where we do a full battery of testing. We go to the same spot all term, so we can see if there are meaningful differences over time. And in the summer period, we have one full week dedicated to Community Action and Volunteering trips, so we also take a bunch of measurements and analyze them in situ. We try to switch up which students take which measurements when – so sometimes you’ll be in charge of the E. coli culture and other times you’ll be responsible for the sensor readings on temperature, electrical conductivity, and pH. And since we’re off the regular school timetable during the summer, the students can really dive in and create presentations based on their results!

SS: So, zooming out a bit: I’m a chemist by training. I studied up to the PhD level and then went to work for Pfizer. But after some time in the industry, I wanted a change, and teaching came up as a possibility. It took me two years to convince my wife I’d be any good at it, but I started teaching 12 years ago and joined Haileybury 4 years ago as a chemistry teacher – and here I am, still going strong!

As far as becoming the facilitator for the Drinkable Rivers hub, my colleague Giovanna Iorio (Head of Service), who is really the linchpin for the Community Action and Volunteering Group, asked me to help out because I’m a science teacher. And now I’ve got scores of water quality data stored in a Google Sheet…!

SS: Very healthy, actually! Hartham Common is a lovely green park where the chalk stream by the name of river Beane flows from its springs in the northeastern Hertfordshire hills into the river Lea – which in turn flows all the way down past London to empty into the Thames.

The local community here really seems to appreciate the river and treat it with respect. There are easily accessible swimming beaches, as well as some sections with locks, weirs, and houseboats. People often go kayaking or paddle boarding, and there are walking paths all along the length of both rivers – which we also use during our summer river walks for Drinkable Rivers.

Honestly, most of our Drinkable Rivers measurements come back really clean. Sometimes we find a little excess phosphate – no doubt from the farm fields north of town. And in the summer, we pick up on some E. coli, but never enough to be of concern for swimmers. It feels good to know that the river is healthy – and also that the swimming spot where my son likes to build river rafts with his fellow cub scouts is safe!

SS: Well, your kit works really well. It’s quite clear with explaining the measurements and what the equipment is intended to do. My first time sourcing replacement materials was an interesting experience. I’m not a biologist, so I never realized there were so many different types of bacterial culture plates that look almost the same but do different things. I really had to make sure I got the right one for the E. coli measurement. Also, I would emphasize that while the E.coli plates are the most expensive material to source, they are also the most visually interesting. It’s so cool for the students to be able to see and count the bacterial colonies. 

And speaking of the students… I’m off to join them for sports class!  

Haileybury was kind enough to share the data they collected during one of their summer measurements with us to showcase in this article. In addition to confirming that phosphate levels were indeed higher than the healthy standard in 9 out of 16 samples, we also ran a quick correlation analysis to see which water health parameters might vary together in their river.

Note: due to the small sample size, we consider this an example of trends that could be explored with a larger citizen science data set.

This correlation heatmap shows where two water quality parameters might be connected. It does not tell us whether these connections are direct or indirect, nor whether one factor has a causal influence on another. Numbers above r=0.7 represent a strong correlation. For example, in the Haileybury measurement, the number of blue (E.coli) colonies counted showed a direct correlation with higher streamflow. This relationship is actually quite common in agricultural and urban catchments. Higher streamflow is usually driven by rainfall and surface runoff, which physically washes E.coli bacteria from animal or human waste off the land and into the river. Meanwhile, the number of red (non-E.coli bacteria) colonies counted varied directly with pH and inversely with the number of emergent plants in the river. Bacteria, like most living creatures, can only survive within a narrow pH range and are especially susceptible to acidic (low pH) conditions; while water plants (macrophytes) often serve as effective filters for pollution – including bacteria. If a larger dataset were to replicate these patterns, we could start to form hypotheses about local factors influencing the river’s health.