2nd July 2026: Routine monthly testing
Wildlife observations
Coots, Canada geese, swan, Egyptian geese, crow, mallard, dragonfly, grashopper, bees, cabbage white butterflies, unidentified
butterflies, unidentified moth, Eurasian wren, robin, squirrel, hornet, parakeet, heron, chiffchaff, black headed gull, swallow.
Water level: -100cm (measured from height of embankment at sample point 2
Summary of water tests
Ammonia: A measure of recent organic pollution, including sewage. Low levels are generally a sign of healthy water. 🟩 <0.1 🟨 0.1-0.5 🟥 >0.5
Phosphate: A measure of long-term nutrient pollution. High levels can encourage algal blooms and poorer river health. 🟩 <0.1 🟨 0.1-0.3 🟥 >0.3
Nitrite: A measure of recent changes in water quality. High levels can indicate pollution or poor river health. 🟩 0 🟨 0.5-5 🟥 >5
Nitrate:A measure of long-term nutrient enrichment. High levels can encourage algal blooms and poorer river health. 🟩 0-10 🟨 11-50 🟥 >50
Conductivity: A measure of dissolved minerals/salts in the water. Used to establish a baseline and identify changes over time. 🟩 Baseline 🟨 Deviation
Temperature: Water temperature affects oxygen levels and the health of fish, insects and other wildlife. Used to monitor seasonal changes over time.
Water level: A simple measurement of water level to track seasonal changes. The higher the number, the lower the water level.
We use Hanna Instruments checkers for ammonia and phosphate, and an HM Digital meter for conductivity and temperature.
Nitrite, nitrate and E. coli are monitored using indicator strips as an inexpensive screening tool. If unusually high readings are
found, we will consider follow-up laboratory testing. This approach allows us to monitor the river regularly while keeping costs low.
River monitoring
An important principle in river guardianship is to focus on a specific area and build up a detailed picture of river health over time. WIth this
in mind, Seething River Guardians focusses on a 5km stretch of the Thames between Hampton Court Bridge and Kingston Railway Bridge.
This stretch includes a lot of different elements including a wide variety of wildlife, the joining of the rivers Ember and Hogsmill and three
Thames Water storm outfalls. We take monthly water quality samples from five different sampling points (S1-S5 on the map) and test for
ammonia, phosphate, conductivity, water temperature as well as visual observations. We conduct additional sampling after events such
as storms or overflow discharge. We also condut a montly survey of wildlife.
Anyone can get involved with recording observations, especially wildlife or pollution. Simply use the form below to let us know what you
would like to report and use the grid references to provide us with a rough location.
Seething River Guardians (SRG) is a voluntary group that support the health of the River Thames
over a 5km stretch from Hampton Court Bridge to Kingston Railway Bridge. .
The objective of Seething River Guardians is to take positive action in a number of ways:
- Water quality monitoring
- Wildlife monitoring
- River health monitoring
- Events such as litter picks (on foot, kayak, paddleb oard etc) and walks
If you would like to be involved then contact stevexoh@gmail.com
SRG is part of a larger River Guardians network supported by the Friends of the Thames charity