Thursday, March 31, 2011

Perchlorate In Irish Drinking Water a Potential Cause of Hyperthyroidism?

Attention is increasingly being focused on perchlorate in drinking water as prolonged exposure is known to suppress thyroid function. The sources of perchlorate in Ireland are quite limited but one area that urgently needs investigation is the use of sodium hypochlorite for water treatment. Other potential sources are household bleach and sodium hydroxide.

Sodium hypochlorite is a very common method of disinfecting water especially in smaller drinking water suppliers. The quality, storage and use of these chemicals varies considerably. When used it will dissociate to produce some perchlorate ions. Wherever sodium hypochlorite and sodium hydroxide are used there is a potential for perchlorate release into the environment.

A study carried out by NSF International in the US, and published in the Journal of the American Water Works Association found that perchlorate was found in 90% of sodium hypochlorite used at water treatment plants with the concentration increasing as the sodium hypochlorite aged. Their conclusions were: “For utilities that routinely use their sodium hypochlorite within 45 days of manufacture, the contribution of perchlorate is likely to be negligible, unless there is some contamination of the original ingredients. Utilities or small systems that store sodium hypochlorite for longer periods may encounter significant levels of perchlorate in the finished drinking water. To minimize the perchlorate risk, sodium hypochlorite should be stored in the dark, at cool temperatures, diluted if possible, and used within a few weeks of manufacture. Storage tanks and piping should also be emptied of aged material and flushed to minimize the potential for contamination.” Link

Tuesday, March 29, 2011

MSc Environmental Sciences

The MSc Environmental Sciences students are spending three weeks with me doing a crash course in hydrobiology.  The 13 students are currently doing freshwater monitoring and are shown here on their third freshwater site visit.

Saturday, March 26, 2011

New Publication of Foam Potential Measurement

Accurate measurement of foaming at activated sludge plants can be subject to large variation. In this study foam measurements are reviewed and two approaches to foam potential assessment are compared. The paper, written jointly by Martin Fryer and Eoghan O’Flaherty of the Water Technology Research Group at Trinity College Dublin, is available on open access at Link.

The full reference is: Fryer, M., O’Flaherty, E. and Gray, N.F. (2011) Evaluating the Measurement of Activated Sludge Foam Potential. Water, 3(1), 424-444. doi:10.3390/w3010424. Free download

Tuesday, March 22, 2011

Today is Word Water Day!

The theme of this year’s World Water Day is ‘Water for cities: responding to the urban challenge’.

Sunday, March 20, 2011

New PhD studentship

A new four year PhD studentship is available with the Water Technology Research Group from September 1st 2011 funded by the Irish Government under the National Development Plan 2007-2013. The project explores the question Can submerged aquatic macrophytes be used under temperate conditions to provide a low-carbon sustainable treatment solution for a range of conventional and problematic wastewaters? The project will be examining a range of native and invasive species, including Lagarosiphon major. Further details can be found here.

Saturday, March 19, 2011

Dangerous gases from Septic Tanks

A number of people have emailed me concerning fumes from septic tanks.  The problem with all stored organic wastewaters that go anaerobic is that large quantities of hydrogen sulphide and methane will be produced.  These gases are much heavier than air and displace the air within the tank, so once opened, the gas will rise from the tank and form a dense layer around the manhole at ground level. Hydrogen sulphide is very dangerous and as I said earlier odourless at high (lethal) concentrations so there is always a potential problem.  The key thing here is to ensure that all septic tanks are cross vented.   Cesspools or sealed septic tanks are highly dangerous in this regard.  The most dangerous scenario is where the tank is in a hollow or the entrance is contained in a riser or in a building so that the gas can build up. Never climb into a tank which has only been partially emptied unless you are sure it has been vented with air.  Most complete treatment systems such as the Biocycle are continuously vented via the aeration system, so that such gases should not build up.  However, if you are working in this area, and some of you who emailed me are, you should always have a gas detector.  It is worth the investment.  For more information see Link and more safety information see Link.

Friday, March 18, 2011

New Publication on Activated Sludge Protozoa

Donata Dubber, a PhD student with the Water Technology Research Group, has just published a paper on the effect of anoxia and anaerobia on ciliate communities in BNR systems. The key outputs of the study were: (i) aeration conditions play a major role in how protozoan communities develop; (ii) activated sludge ciliates display different tolerances to anoxia/anaerobia; (iii) short times of anoxia enhance protozoan community complexity; (iv) with anaerobic conditions protozoan community complexity and abundances decrease; and finally (v) to ensure optimum performance lengths of anaerobia should be as short as possible.  The research is funded by Science Foundation Ireland.
The full reference is: Dubber, D. and Gray, N.F. (2011) The effect of anoxia and anaerobia on ciliate community in biological nutrient removal systems using laboratory-scale sequencing batch reactors (SBRs). Water Research, 45, (6), 2213-2226.   doi:10.1016/j.watres.2011.01.015

Thursday, March 17, 2011

Fishing on the River Dodder

Happy Saint Patrick's Day
I was walking past a well known Fishing Tackle Shop in Dublin today and saw fishing permits for the River Dodder on sale. It is not a huge river but hugely popular for fishing which is controlled by the Dodder Anglers Club and also of course the riparian owners. The Club supplements the natural fish stocks annually by restocking with brown trout ranging from 4 -16 ounces with sea trout occurring at Ballsbridge. At €10 for adults and €5 for juniors it  really is a remarkably cheap permit, especially as the river flows through Greater and Central Dublin and this is where the best fishing is to be found. A useful introduction to the Dodder is the recent catchment flood report commissioned by Dublin City Council. Link

Wednesday, March 16, 2011

Fumes from stored sewage claims life

The sad new that one man has died and a second has been taken to hospital when they were overcome by fumes while emptying a commercial septic tank in East Cork has reminded us all of the dangers of working with stored sewage.  Always be aware of the danger of fumes when working alongside or inside tanks and chambers, over open manholes and in all enclosed spaces where sewage, sludge or slurry is present. Please remember always to be vigilant and carry a gas detector unit with you. Hydrogen sulphide can render you unconscious in seconds and is undetectable at lethal concentrations.

Grand Canal: The heart of Dublin City

For those of you who don't know about the Grand Canal and how much a part of Dublin it is, here are two great videos showing just how much a part of the City it is.

Tuesday, March 15, 2011

Japanese Earthquake and Tsunami

I don’t need to say anything about this appalling tragedy except that clean water and sanitation provision are vital after such emergencies and the shear scale of this disaster is putting even the resources of a wealthy country like Japan under pressure. The Japanese Red Cross is playing a vital role in co-ordinating the international relief effort. If you would like to make a donation to help Japan at this difficult time then Google have set up a simple donation system. Link

Monday, March 14, 2011

Swan mortalities on the Grand Canal

Seventeen dead swans were recovered from the Grand Canal in Dublin  between the 9th and 10th of March and a further ten seriously ill swans removed from between Portobello Harbour and the Suir Road Bridge. Initially it was thought this was due to Avian flu but this has subsequently been ruled out with experts now believing the cause to be a bacterial disease, most likely botulism. However, what is of concern is that this is close to the area currently being dredged and that dead fish have also been reported. The dead animals are undergoing tests at the State Laboratory although confirmation of the cause of death is not expected until the end of the month. Swans are particularly vulnerable to sudden changes in water quality and contaminated food resources, especially in urban locations on canals where they do not find it easy to move from one enclosed stretch to another. In my opinion a possible link to the dredging activity does need to be positively ruled out so that this important maintenance work can continue in future years with any necessary safeguards in place.

Sunday, March 13, 2011

Word Water Day 22nd March 2011

The theme of this year’s World Water Day is ‘Water for cities: responding to the urban challenge’. The aim is to focus attention of all stakeholders to the challenge of urban water management to deal with the impact of rapid urban population growth, industrialization and uncertainties caused by climate change, conflicts and natural disasters on urban water systems. Link

Saturday, March 12, 2011

Dredging continues along the Grand Canal in Dublin

Grand Canal
Waterways Ireland is continuing to dredge sections of the Grand Canal in the City Centre to keep it navigable for large boats. For those of you who travel on the Luas you will notice that sections are currently devoid of water as sediment and rubbish are cleared. This means the section between Lock C4 (Baggot Street) and Lock 1 (Suir Road) will not be navigatable. This work will be completed by April. Although the National Parks and Wildlife Service are advising the company on how to minimize damage to the wildlife of the canal, much of the freshwater flora and fauna will simply be removed or destroyed by the work. The Canal is a unique reservoir for Irish freshwater biodiversity but the periodic dredging work is unavoidable to prevent the canal from completely silting up. Further details.

Thursday, March 10, 2011

Massive investment for flood protection in England

The Department for Environment Food and Rural Affairs (defra) announced 39 new flood and coastal defence projects throughout England last month, 21 one of these are to reduce to risk of flooding protecting over 13,000 households. This is part of an enormous programme involving nearly 300 projects which are managing the risk of flooding costing £521 million in the coming year. Full datails of the projects can be accessed here.

Saturday, March 5, 2011

Wednesday, March 2, 2011

Water Quality in Ireland 2007-2009

The season for National reports continues with the latest  report on the surveillance programme of Irish water quality dealing with rivers, lakes, estuaries and groundwaters has been published by the Environmental Protection Agency. The report Water Quality in Ireland 2007-2009 can be downloaded from the EPA website.

The programme monitors some 13,118 km of river channel comprising 1,700 rivers, as well as 222 lakes, 89 estuarine and coastal sites and 211 groundwater monitoring stations. The problem with all such surveillance programmes is that not all water bodies can be included so there are many gaps in what is being monitored. However, having said that, the overall conclusion is that water quality in Ireland is being maintained but according to the EPA themselves the quality of Irish water quality remains only just above the European average which is disappointing. The reports shows that 70% of river channel is of good quality status in accordance with the Water Framework Directive although the remainder are polluted to varying degrees. Overall, 85% of groundwaters were also of good status and 90% of lake area is in a satisfactory condition. The EPA remain committed to improving water quality in Ireland.