Tag Archives: Pollution

Knowing your rudd from your roach

Our lucky Pollution Patrol volunteers were treated to a FIN-tastic day with our local Environment Agency team, learning all about fish.

It may come as a surprise to some people, but the Hogsmill, Wandle and Beverley Brook all contain a variety of different fish species. Common species across all three rivers include chub, dace, roach, barbel, stickleback and European eels.

But how do you tell the different between these species? For some, it is easier than others. The European eel is quite distinctive compared to the others for example. But as to the rest, it’s a bit more difficult.

Tom Cousins, a local EA Fisheries Officer, started the day for us with a presentation on the different fish species and the key identifying features.

The diagram below shows the external morphology of an average fish, and the features that help us distinguish one species from another.

For example: Roach and Rudd

These two fish are quite similar in appearance, both large-bodied with reddish fins. So how can we tell them apart? The answer is by looking at the mouth.

The roach is a bottom feeder, and its mouth points downwards, with the upper lip over-hanging the bottom lip – whereas a rudd feeds from the surface, and therefore the bottom lip overhangs the top lip.

The presentation from the Environment Agency is available below for you to download, with many more tricks and tips for ID.

Fish ID Presentation

As part of the training day, we also got to witness the Environment Agency’s electrofishing survey at Morden Hall Park on the River Wandle in South London.

It was amazing to learn about the fish in the classroom, and then come outside and see some in the flesh. Each fish caught was measured, and scale samples from some were taken in order to age the fish.

Once they had been recorded and had recovered, they were returned safely back to the Wandle. 

Many thanks to Morden Hall Park for hosting us and to the Environment Agency for running the event!

Volunteers Join Forces for the Hogsmill

The Hogsmill river doesn’t know how lucky it is!

Last week, 30 volunteers joined SERT and ZSL at London Zoo for the 2017 Hogsmill Forum.

2017_hogsmill_forum_ZSL

The Forum is an opportunity for us and ZSL to say thank you to all the volunteers who help us with our projects on the Hogsmill – Pollution Patrol and the Riverfly Monitoring Initiative.

It is also a chance to share wider plans for the river with the local community,  discussing ideas and actions for the coming year; all of which feed in to the Hogsmill Catchment Partnership which SERT host.

If you are interested in either project, get in touch – volunteering@southeastriverstrust.org

And why not have a read of these presentations which our speakers delivered through the course of the day?

Presentations:

Many thanks to ZSL for hosting us, and for letting us have a look around the zoo after the meeting!

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Water quality improvements are on par at Richmond Park

Shortly I will post another blog updating you on how the river improvement works in Richmond Park are settling in one year after they were completed. Although the river habitat works have been completed (for now!) work has by no means ended. In addition to improving the habitat, our attention is also focused on addressing the poor water quality entering into the Brook.

Upstream of the Richmond Park golf course, rain water pours off the surrounding urban catchment and notably down the incredibly busy and often choked A3 at Roehampton Hill. It then flows down the gulley pots, into a surface water drain before this opens out into a ditch which flows across Richmond Park Golf Course before discharging into the Beverley Brook. Such road runoff is known to cause detrimental effects to the aquatic environment, not only from the significant quantities of sediment carried in it, but additionally from the contaminants bound to it. These include Poly Aromatic Hydrocarbons (PAHs), hydrocarbons and heavy metals. Our aim was to therefore capture the sediment and the contaminants before they reach the Brook. This was achieved with a two pronged attack.

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Oil from the A3 covering the surface of the pond in the golf course. Thick black sediment covers the bed

First of all, mid-fairway at the upstream end of the golf course we opened the ditch out to create an on-line pond, known to us as a silt trap but to golfers as a feature water hazard. With help from Rob McInnes, the pond’s size was calculated so that all coarse sediment down to 0.1mm would drop out as a consequence of lowering the velocity of the flow. A shallow marginal ledge was incorporated along the length of the pond, which has been planted with a mix of wetland plant species to promote deposition, whilst providing species and habitat diversity. By emptying the pond regularly, the silt is removed from the system and the effectiveness of the trap is maintained.

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Starting to open the ditch out

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A few months after completion, the pond is trapping plenty of silt (and plenty of golf balls)

The second measure took place a few hundred metres further down the ditch where an existing online pond, in the shape of a ring doughnut, provided an excellent opportunity to be modified to create a wetland. The plan was to re-jig it so that the doughnut became a U-shape. This prevents short-circuiting, therefore increasing retention times, reducing velocities and again promoting a depositional environment.

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The pond before works start

The pond was too deep to plant straight into, so we needed to find spoil to fill it in. What better way to produce the spoil than dig a second wetland immediately upstream of the first, which will increase the treatment capacity further.

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Re configuring and filling in of the pond

Six thousand plants consisting of over 20 species were planted in the wetlands. The dense structure created by the plants results in even finer sediments being captured than in the silt trap upstream.

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The wetlands newly planted with 6000 plugs and fenced off

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August and the plants have established

Furthermore, this has now created a fantastic wetland habitat full of dragonflies, damselflies and frogs to name a few. Both the silt trap and wetlands have been fenced off and have bird twine strung over them to prevent the large population of geese from nobbling the plants before they had the chance to establish. The total area of both is approximately 800 metres square.

A simple water level control structure was created at the outlet of each wetland. As sediment accumulates and reduces the depth of water over time, another drop board can be put in, allowing the water depth to be increased, therefore reducing maintenance requirements and prolonging the life of the wetland.

The effectiveness of the installed measures is currently being monitored, however a coincidental site visit during a pollution event helped to anecdotally demonstrate the effectiveness. Run-off from a presumed building site was bringing significant quantities of sand rich water into the ditch. After the silt trap, the turbidity of water flowing out was visually improved. Walking further down the ditch network, after flowing through both wetlands, we were incredibly impressed to see that the water flowing out and into the river was clear to the eye. Although this was always the theory behind why we created these features, to see it work first hand to such a great effect was brilliant and hugely satisfying. With contaminants generally being bound to sediment, this clearly demonstrates not only a reduction of sediment input to the river but indirectly of contaminants too.

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Thick sandy water flowing into the sediment trap

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Water in the ditch downstream of the sediment trap and both wetlands

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Significantly improved water clarity entering into the Beverley Brook

Job done!! (for now anyway). I am now working up the next phase of water quality improvements. Updates will follow shortly.

As always, the success of this project is down to the valuable contribution of many people and organisations.

Big thanks to the ongoing project partners; the Environment Agency, Defra, The Royal Parks and Friends of Richmond Park. Thanks to Jon Dummett and Gary Stewart at Glendale Golf Course for surprisingly being so willing in allowing us to dig up their course and for their continued support since. Thanks to Rob McInnes at RM Wetlands & Environment Ltd for guiding the designs, Ben and the guys at Aquamaintain for braving the cold February days delivering the work and again for planting it up. Thanks to Thames Water for providing the flow meter which was installed in the ditch network to inform the design and finally, to Layla at Queen Mary University for monitoring the work.

Outfall Safari on the Hogsmill

ZSL and the Hogsmill Partnership are looking for volunteers to help us map polluted outfalls on the Hogsmill this October.

While walking the Hogsmill you may have noticed all the different pipes that can be found along the river bank. These pipes are usually part of our surface water infrastructure, transporting clean water from our roads and roofs into the river. However in some cases, these pipes or outfalls can be polluting the Hogsmill as they have been misconnected.

Polluted Outfall

Misconnections are a BIG issue for urban rivers and the Hogsmill Catchment Partnership have been working hard to start addressing this on the Hogsmill River.

A misconnection is when a toilet or washing machine has been connected to the surface water drain heading straight to the river, instead of the sewer system. You can read more about misconnections at on the Connect Right website.

Connect Right

This October, ZSL are running an Outfall Safari to map all these pipes heading into the Hogsmill, and assessing their condition to check for misconnections.

Volunteers will receive training on how to recognise signs of pollution at these outfalls and record the pipes on a new smartphone app. This survey data will greatly improve our understanding of the river system and help to target sources of pollution.

Interested?

If you would like to join the team, you can sign up on EventBrite to register your interest. Once you’ve registered, more information will be sent to you about where and when the training sessions will take place.

Sign Me Up!

For more information contact by email: Joe.Pecorelli@ZSL.org, or phone: 07974 725 557
Outfall BannerPlease register your interest to help at: hogsmilloutfalls.eventbrite.co.uk

You’ll need to read this before your training session: 2016-Pre-training-information-for-Hogsmill-Outfall-Safari-Volunteers..pdf

New London Partnership Project to tackle Urban Pollution

We have teamed up with Thames 21 on a new project to tackle urban pollution across London’s rivers.

Many improvements in the quality of urban rivers have been made in recent years, but lots of serious water quality issues remain. One of the biggest issues is ‘urban runoff’, where a toxic mixture of contaminants derived from urban areas drain straight into rivers.

With surface water drains often running straight into rivers, these contaminants are washed directly and unfiltered into urban rivers when it rains. During these ‘first flush’ events, river water often changes from being clear and colourless to being an opaque grey-black colour, and water analysis shows that a complex mixture of hydrocarbons, fine particles, nutrients, microorganisms and heavy metals are the cause.

First Flush samples from the River Wandle

First Flush samples from the River Wandle

In urban areas the contaminants causing rivers to run grey-black in colour may have a greater impact, but the locations at which they enter a river are often unknown, and they are relatively costly to survey, with samples needing to be processed by a lab.

Our project with Thames 21 is testing a low-cost sampling method that can be used by volunteers to identify complex urban contamination. In particular, it aims to investigate Surface Water Outfalls (SWOs) which discharge contaminated urban runoff into London’s tributaries of the River Thames.

The method being developed is based on evidence from data collected on the River Wandle, and urban sites in Wigan in NW England, which show that Total Suspended Solids (TSS) are strongly correlated with several important heavy metals and E. coli (a bacterium which can indicate faecal matter) and can therefore be used as a low-cost proxy to identify problematic concentrations of these contaminants.

The next step in this project is for us and Thames 21 to create Pollutant Profiles for our rivers to see if they match this correlation. You can follow progress on the project on our Twitter feed @SE_Rivers_Trust with #TSS!

The 2016 Hogsmill Forum

The Hogsmill River may have its problems, but it is one of the lucky urban rivers to have huge community support and many enthusiastic volunteers.

We run our Pollution Patrol on the Hogsmill, tracking down polluted outfalls and misconnections. While ZSL run the Riverfly Monitoring Initiative which uses the kick sampling of invertebrates to check for organic pollution.

So to thank everyone for their hard work, both projects combined for a joint Hogsmill Forum – kindly hosted by ZSL at London Zoo.

Hogs Forum

The event was a huge success with some really interesting discussions on the priorities for the Hogsmill going forward. Below you can download PDFs of the presentations.

Presentations:

 

Happy Anniversary to the Hogsmill Pollution Patrol

Pollution on the HogsmillWith the start of 2016 comes the One Year Anniversary of our Hogsmill Pollution Patrol scheme – and what an amazing job it has done so far!

Throughout 2015, our trained volunteers have been monitoring 15 outfalls on the Hogsmill for signs of pollution such as misconnected appliances and sewage discharge.

Together they have submitted 470 reports of pollution to us. Working with the Environment Agency and Thames Water, we have been able to start investigating these issues and begin work towards rectifying them to improve water quality on the Hogsmill River.

To read the latest update of our work, please download our Newsletter below.

Pollution Newsletter December 2015

If you see pollution on your river, call the Environment Agency hotline on:

0800 80 70 60

Pollution

Pollution-Busting on the Wandle

Over the last 2 years, the Wandle Trust has been intensifying efforts to tackle the considerable problem of pollution in the river. Often contamination can be tackled by our partners in the Environment Agency, tracking down pollution to the source. However, this does not work for all sources of contamination.

For example, contaminants such as particles from car exhaust, the loss of engine oil and other contaminants from the roads can all be washed into the river from no one “point” source. This is known as diffuse pollution.

DiffusePollutionTo illustrate this, there are about 2.5 million cars in London, and 16% of them leak oil. It has been calculated that this would equate to 261,635 gallons of oils dripping onto roads every year! Much of this oil will work its way into London’s surface water drains and then the rivers.

Although changes to the law and car technology may help one day in the future, we need to start acting now. It has been the Wandle Trust’s mission to find out how the contaminated waters from the surface water drains can be cleaned up before entering our river. This is vitally important because water quality is a major determinant of what wildlife can live in the rivers, how beautiful the rivers are, and how much the community value their local water landscapes.

In the current phase of our Pollution Busting Project, four measures are being installed and trialled to determine their effectiveness in reducing the contamination coming into the River Wandle. These measures are the most promising selected from several which were investigated by the Trust and they are called:

  • Downstream Defenders
  • Mycofilters
  • Siltex
  • Smart Sponges

There will be more information about these appearing on our websites in the coming months. We look forward to telling you more about this exciting new phase of our work!