Earthwatch Water Blitz




Nitrates 10 and Phosphates 0.5

The second Water Blitz of the year - coordinated by EarthWatch - was undertaken during 2.10.17, at locations along the Hogsmill river similar  to those of the May Blitz. Starting with Knights Park TQ18536872, the nitrate level was high - scoring 10 in the sample tubes from the kits that are issued to us. All sites went on to score 10 for nitrates unless otherwise stated.



Hogsmill SW outfall
 
Just below the outfall at the Hogsmill Sewage Works TQ19156857, phosphate levels were the lowest of the survey at 0.1. Is this the result of phosphate stripping? The highest phosphate level was achieved at the Channel of Cess (CoC), the small stream entering the Hogsmill at TQ19866831.




Sewage fungus
 
In addition to the highest (therefore the worst of the chemical readings) there was a strong odour, milky colouration, sewage fungus and fresh rag lined the channel. This type of chronic pollution can be  reported to the Environment Agency on 0800807060 and is given a reference number in this case NIRS 01559048.



Tomato plant in a culvert
 
As we walked upstream towards another pollution hotspot at Green Lane Recreation Ground TQ20056788, a tomato plant was seen growing out of a culvert. Tomatoes and figs often indicate the presence of sewage, as tomatoe seeds pass intact through the gut. Phosphates scored 0.2-0.5



new habitat creation

Despite all the instream habitat improvements at the A240 Tolworth - see previous posts - the is still an unhealthy outfall and an amount of sewage fungus around its environs. True to form the scores equalled the CoC.


Currently, there are over 1800 data points collected across the Thames Catchment undertaken with volunteer effort. A new mapping application allows you to visualise, analyse and download all the data collected during the different WaterBlitz .


The map can be access through the Freshwater Links here:

https://freshwaterlinks.org













Comments

Post a Comment

Please share your thoughts

Most viewed

Heritage Trees part 2: street trees.

Image
  Oaks and maples Cambridge Gardens 2019   Street trees can often be the most beautiful objects in our streets. They are important to their communities as well as having environmental benefits. They are a living history in our landscape and can have particular connections. They may be fragments of a previous landscape incorporated into a modern street scene, such as the oaks at Cambridge Gardens once  part of the Duke of Cambridge's estate.  A great read with information on how to research street trees is a  History of Street Trees by Dr. M. Johnston.  London plane trees CRE 1976 Beech tree, Chesterton Terrace 1976 Studies show that the difference in local tree cover can reflect the various socio-economic groups. In Victorian times middle class areas were planted with many street trees or had higher quality front gardens than working class districts; now referred to as 'green equity'. It can be demonstrated by looking at old photos of the seven...
Read more

Fishing the Hogsmill

Image
Fly-fishing the Hogsmill   It is interesting to see the river from a different perspective: the Hogsmill is popular with anglers at this time of year; although it is unusual to see someone fly- fishing. A chub has just been caught on bread and it looks a good size. Trout are sometimes seen in the Hogsmill and can sit in the weir notch by the school. Our own Richard Jefferies in his book 'Nature Near London'  remarked on the Hogsmill trout as far up as Tolworth Hall Bridge (now the A240). chub    This fish was carefully unhooked and orientated in the swim where it soon finds it way - probably to the next father and son - sitting further upstream. These anglers have caught the 'ghost' koi within the last two weeks and appear to be the second successful pair to catch the pond-escapee in the last few days. Ghost koi are a British invention. They were produced by accident in the early 80’s when a farmer allowed a mirror carp and a koi to spawn together. The offspri...
Read more

Seething Wells: they've done it again

Image
The last day of May, I went to see if I could find the black redstart that had been widely reported, no luck but it will turn up again on one of the old buildings. The lush vegetation was looking beautiful between the Filter Beds at Seething Wells. I made a note of the breeding birds: goldfinches twinkling away, blue tits gathering food, sand martins flying over the FB's (only two this year unfortunately) moorhens and some scruffy little coot chicks entangled in the algal blooms.   Proud parents were showing off their four Canada chicks; they can cover a lot of ground in a short space of time they were soon feeding on water pepper and bistort gleaned from  the ziggerat-sided basins. A song thrush sang from the wharf alongside greenfinches as well as the seasonal chiff chaff; although this year all numbers are down, reflecting not only the topsy-turvy Spring but also the continued tumble in insect numbers (even seed eating birds are dependent on insects to feed their youn...
Read more