Down & Dirty in the Sewage System

  • Groundwater already heavily polluted with pesticides, hydrocarbons, solvents.
  • £20 million plan by Southern Water for Thanet sewer upgrade; but changing weather patterns, development mean pumping station investment urgent
  •  KCC needs to invest in “Sustainable Drainage Systems” as matter of priority; “SUDS for Floods” says Green Party candidate for Thanet North.
Storms (and Southern Water) spew sewage out to sea...

Storms (and Southern Water) spew sewage out to sea…

Summer in Thanet was marred on several occasions by great squirting, mephitic expulsions of faeces, tampons, condoms, wet wipes and other detritus from the drains of the area into the otherwise largely clean waters off some of our best beaches. Shit was on the sand and wee was in the water.

Southern Water, blamed the fact that it had been raining heavily, saying there was just too much storm water in the sewers & that it was released “heavily screened”. It was peak holiday season in an area heavily dependent on tourism and off a coastal stretch identified as one of the 17 most sensitive marine areas in England.

The beaches stank, the sea was polluted and signs went up warning against a dip—for those who had lost their sense of smell. How did this happen? How can it be stopped? And is anything being done to make sure it doesn’t happen again? I’ve been thinking about this ever since, in the rare idle moment I get, so I started digging through reams of PDFs this week.

First thing I spotted – in a submission to water regulator Ofwat in June – was that Southern Water claim to be working on a “Thanet Groundwater Protection Scheme: A Major Sewage Upgrade Scheme to Prevent Ground Water Pollution”, so this week I called them up to find out more. It took few emails back and forth, but their press officers were responsive and pleasantly professional (credit where due).

The company is indeed planning to spend £20 million on upgrading the sewerage infrastructure around Thanet between 2010-2020. I asked the good people at their press office what exactly they were doing to make things better and funnily enough they’d just cobbled together a press release. Here’s what they had to share with me:

Southern Water is upgrading the Victorian sewers across the Thanet area over the next ten years. This starts with key work in the Ramsgate area which aims to protect the environment and groundwater as well as reducing the risk of flooding. This work has already started and will now continue in order to complete the key upgrades in Ramsgate by March 2015.

Southern Water is working… with the Environment Agency, Kent farmers and businesses in the area, [to] protect the local environment and groundwater. Kent sits on a chalk aquifer from which Southern Water extracts water supplies; these water supplies have to be treated before being provided to residents. For this reason it is important that we protect this groundwater from potential pollution.

The sewers in Ramsgate were built more than 100 years ago by miners digging tunnels through the chalk up to ten metres underground. These tunnels remain in place and continue to act as a conduit for the sewerage pipe network in the area. Our partners Clancy Docwra will be working in the area to construct new manholes and enlarge some existing manholes. This will then allow them to work in the ground to rehabilitate existing sewers and install new ones.

In a further email, I was told, after asking for a capex figure, that the sewer upgrade project “Phase One and Two” will cost around £20 million. I was also referred to an earlier press release, following a visit by Laura Sands MP to the Foreness Point pumping station in Margate and told rather cryptically that there are unspecified “other plans” being looked at to improve performance.

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Southern Water claims to have invested £3 million in improvements at the pumping station over the past four years, including on “installing new transfer pumps to reduce blockages; improving the site’s screens and associated machinery to remove more items such as wet wipes from the wastewater flows and reduce blockages and installing better back-up systems.”

(The company told me: “In 2010-11, we removed six skips of wet wipes and other non-biodegradables in the year from Foreness Point, last year we removed 26 skips which demonstrates the increasing use of wipes and other non-biodegradables…”)

Margate’s Foreness Point Pumping Station is designed to cope with a 1-in-50 year storm, processing a maximum of 7,400 litres of wastewater per second during storm. During a normal day, the flows are around 300 litres per second. The site also has storm tanks available which hold some of the additional flows which are put back into treatment after a storm has passed. However, if the storm is greater than a 1-in-50 year event, the storm tanks fill and everything goes sloshing out to sea through the CSO.

Discharges in previous years left the company with a frankly puny and inadequate £200,000 fine earlier this year. Lord Chief Justice John Thomas, noting 160 previous offences, said: “This court would not have interfered with a sentence very substantially greater than the fine imposed on this company.”

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Who, incidentally, are Southern Water? Bought from RBS in 2007 for $4.1 billion by a consortium of infrastructure funds led by JP Morgan (which, incidentally, receives an estimated $14 billion in subsidies from the US Federal Reserve per year), they made a fat £169.8 million in net profits in the most recent financial year. That was up 8.2% on the previous year. An unhealthy track record of pollution, fines and what judge Thomas dubbed: “A persistent record of criminality” don’t help further their cause.

They are the obvious bad guys and utility privatisation is where large parts of this problem started: an investigation by Corporate Watch into the finances of the 19 water and sewerage companies in England and Wales found last year that:

  • Almost one third of the money spent on water bills goes to banks and investors as interest and dividends.
  • People are paying £2 billion more a year – or around £80 per household – than they would be if the water and sewerage supply was publicly financed.
  • Six companies are avoiding millions in tax by routing profits through tax havens, using a regulatory loophole the government has chosen to keep open.
  • The CEOs of the 19 water companies were paid almost £10m in salaries and other bonuses in 2012.

The finger here also needs to be pointed at Kent County Council, because there are multiple overlapping jurisdictions when it comes to sewerage systems in the area and it takes a lot of parties to fail to tango.

Someone at KCC has been paying attention however and consultancy Atkins were hired last year by Kent County Council, Southern Water, Thanet District Council, and the Environment Agency to develop a fully Integrated Catchment Model (ICM) of Margate (approx. 35 sq. km) representing the full drainage arrangement (foul, combined, storm), watercourses (approx. 3km), and tidal interactions. That ICM is now reportedly being used to develop an Action Plan.

It identified that a summer storm falling on a saturated catchment has been responsible for over 60% of the flood and beach water quality incidents. i.e. Water drainage is a massive problem. So whilst building a bigger and better pumping station is one answer, the root cause would be a helpful place to address issues too. “The Action Plan will be finalised at a stakeholder engagement event where the proposals of surface water removal (through the use of SUDS), planning restrictions, and upstream storage schemes will be agreed”, Atkins said last year.

It was not immediately clear to me how much progress KCC have made on this, although I’ll be chasing them up.

When it comes to traditional drainage, the idea is fairly simple: pipe everything from cities as soon and as fast as possible. But this way of doing things can have hazardous knock-on effects. Collecting run-off from hard paving and roofing can increase the risk of flooding, plus this surface water run-off is often seriously polluted. Also by diverting rainfall to piped systems, ground water depletion becomes more likely. Growing development clearly exacerbates this problem. There’s less places that water can simply be absorbed healthily.

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In Thanet in particular that is a massive problem. As KCC officials have noted:

The Kent Isle of Thanet Groundwater Body is contaminated with nitrates, pesticides, solvents and hydrocarbons at levels that are of concern. To prevent further deterioration and hopefully to show some improvement in quality The Environment Agency have developed a comprehensive long-term strategy. (It should be noted that the contamination levels are only in the “raw” groundwater).

The reasons for this are manifold, but mostly owing to the fact that the underlying geology in Thanet is very permeable owing to the particular the bedrock (Thanet and Seaford Sand Formation, Margate Chalk Member and Seaford Chalk Formation). As KCC earlier put it (link as above):

Thanet groundwater is extremely vulnerable to contamination as substances (natural substances and man-made chemicals) are able to pass rapidly through the thin soils and the natural fissures (cracks) in the Chalk rock to the groundwater below the ground surface.

One important answer to this is, as Atkins noted, so-called SUDS, which rather than simply hastening ground water run off into pipes as fast as possible, by contrast are made up of a series of devices and techniques which encourage the water to remain at source and to dissipate slowly; examples include swales (often traditional flood plains), also permeable paving and green roofs to mimic the natural drainage of a site and reduce the speed of run-off.

All sorts of imaginative things can be done with storm water. As blog The Dirt reports, in Illinois, Hoerr Schaudt Landscape Architects have completed work on The Circle. The Circle’s a sustainable roundabout that cleanses – through filtration bogs, ultra violet sanitizers, and a “structural cell system” and recirculates storm water into a public fountain providing community green space and making a fairly decent roundabout at the same time. (Read more about it here. Pretty innovative stuff).

To wrap up (congratulations if you have read this far!) I’d say that given the increased heavy flooding we are seeing and shifting weather patterns, that Southern Water need to substantially boost capacity at Foreness Point – there is simply no excuse for failing to invest heavily in that, particularly given the length of time it will take to address root surface water problems. KCC also need to bring forward their work on SUDS in Thanet as fast as possible. The area could be a great example of best practice in the sector.

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One response to “Down & Dirty in the Sewage System

  1. Pingback: Dirty Water | Targett for Thanet North·

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