Blue tap water at two schools has been found to contain three times the legal level of copper.
Pupils and teachers at Buchanan High and St Ambrose High in Coatbridge, North Lanarkshire, were told not to drink tap water in December, three years after the first warnings that it was running blue.
Now the results of tests show the amount of copper in the water was more than three times the permitted levels in the home economics room and nearly double in the school kitchen.
The tests also revealed water in the staff room and the school kitchen failed to meet regulated standards because of the presence of coliforms – bacteria which indicate faecal contamination.
The schools share a campus, which was built on a former landfill site for industrial waste.
However, the contamination may come from the copper pipework, which is being replaced with plastic.
Teachers have raised concerns over the blue water issue affecting their health, with figures showing Buchanan High has the highest rate for teacher sickness absence in North Lanarkshire.
But legitimate questions do remain over what is causing this in the first place.
Microbiologist Professor Hugh Pennington said: “There shouldn’t be any coliforms in drinking water, there should be zero, so there is something wrong somewhere.
“Coliforms themselves are a harmless bug, but they indicate faecal contamination.”

E. coli has been detected in the water supply to one Wairarapa town.
Photo: RNZ / Karoline Tuckey The South Wairarapa District Council said a boil water notice has been issued for anyone connected to Martinborough’s water supply.
The notice was issued after low levels of the bacteria were found in the town’s drinking water on Friday.
Water is being trucked in for people to drink at today’s Martinborough Fair, as the water supply is contaminated.
200 litre tanks of fresh drinking water will be stationed around the town square but organisers also recommend people bring their own water if possible.
South Wairarapa District Council assets and operations manager Lawrence Stephenson said testing was underway to trace the contamination.
"All our testing of the actual water going into the network has come out clear and the treatment plant itself has been operating well.
We’re trying to identify the source in the actual network."
Mr Stephenson said water in Martinborough was not chlorinated, as the chlorine reacted to manganese in the water, turning it brown.
Copyright © 2019, Radio New Zealand

Coimbatore: Over 60 families residing in and around Karuparayan Kovil Street extension at Puliyakulam have been struggling after the city corporation stopped supplying drinking water to the area one-and-a-half months ago.
“Most of us used to collect water from the tap whenever it was supplied, that is, once in eight days.
We filed a complaint to the city corporation officials after receiving water contaminated with sewage in December.
It was the last time we received drinking water,” she told TOI.
R Sivagamani, another resident, said the corporation’s water tanker supplied drinking water only three times.
Some people managed to get a few buckets of drinking water from our neighbourhood areas.
But as it is supplied only for a couple of hours, there is a huge rush to collect it.” A corporation official in charge of providing water to the locality said that works are progressing to stop pipeline leak and check sewage contamination.
“We had to dig up at eight places to find the leaking pipe.
It has been fixed.
Most likely, the residents will receive non-contaminated water from Monday,” he told TOI.

Many, if not most, of the 62 First Nations reserves in this country that lack a safe water supply are found in isolated areas, far from where most Canadians live.
Not only do they deserve access to drinking water that is not contaminated, that won’t give them a rash, make them sick or, in extreme cases, kill them; they have a right to it.
It is a fact of life in far too many Indigenous communities that their tap water is unfit for consumption without first being boiled.
When Justin Trudeau became prime minister in late 2015, there were no fewer than 105 long-term boil water advisories on First Nations reserves.
At that time, Trudeau’s promise to make these long-term drinking water advisories a thing of the past in every First Nations community by 2021 was greeted with disbelief.
Since November 2015, 78 long-term drinking water advisories have been lifted.
Life is better in those communities, even if they still face challenges unimaginable to most Canadians.
Moreover, the integrity of First Nations water systems can’t be judged solely by the number of water boil advisories.
Other federal government data suggest the improvements to those water systems aren’t as significant or permanent as the end of all those drinking water advisories might lead us to conclude.
Even so, the government has a long way to go.

KARACHI – Sindh Minister for Health Dr Azra Fazal Pechuho has said that typhoid has consistently been spreading in the province owing to contaminated water, fearing that the situation could become worst if not controlled.
Replying queries during question hour in Sindh Assembly, Dr Azra said that water distribution system was very old and not up to the mark as sewerage water gets mixed with drinking water due to which typhoid and other diseases were spreading.
The provincial government is taking several measures for provision of clean water to the people but there is need to a lot more” .When asked about the measures being taken by the department to fight against Typhoid, Dr Azra informed that ‘Polysaccharide’ vaccination was done through child survival program to the eligible children as well as conjugate Typhoid vaccine campaign was being carried out in affected areas of district Hyderabad through collaboration with Aga Khan University Hospital.
Training plan for the mass vaccination has been completed for Karachi, while it is in process in other parts of the Province,” she added.
“We don’t want to create panic until obtain required number of dosage.
‘Seven died of Naegleria’ The Health Minister informed that seven people died of Naegleria Fowleri Infection (NFI) across the province.
“Naegleria can only be prevented through chlorination of water and other measures for leak proof supply of water,” said Azra.
The minister was of the view that the role of health department was very limited as it could only impart health education, conduct public awareness sessions through print and electronic media for maintaining hygiene and to share the chlorination of water status with KW&SB for taking pre-emptive measures so as to avoid deaths due to NFI.
However, she added that they constituted a focal group to formulate strategy for control of NFI for water sampling and testing from pumping stations, reservoirs of KW&SB, monitoring of swimming pools of hotels, farm houses and recreational water parks for assessing chlorination status and its functional system.
“24000 chlorine tablets were distributed among the affected community to prevent water borne diseases,” she added.

ST. PAUL — The Coalition of Greater Minnesota Cities is supporting bills in the 2019 legislative session to provide $128 million for clean water infrastructure projects, officials said this week.
According to a press release, the bipartisan bill the coalition is supporting would help cities offset the growing demand for projects to upgrade and rebuild water treatment plants and other infrastructure.
The legislation, authored by Sen. Gary Dahms, R-Redwood Falls, and Rep. Jeanne Poppe, DFL-Austin, provides $128 million to general appropriation bonds.
“Cities are the front line of protecting our lakes and rivers from pollution, and making sure residents have clean water,” said Ron Johnson, Coalition of Greater Minnesota Cities president.
“We are proud to play a role preserving Minnesota’s clean water legacy, but simply don’t have the resources to make the necessary improvements to their water facilities without assistance from the state.
The funding is especially critical this year, the release states, as several cities have been forced to put important projects on hold after funding in the 2018 session was delayed because of a lawsuit challenging the funding mechanism.

BENNINGTON, Vt. — The state of Vermont reached a tentative agreement with a plastics company to address chemical contamination in more than 150 private wells on the east side of Bennington, the state announced Tuesday.
The Agency of Natural Resources said an agreement in principal with Saint-Gobain Performance Plastics will expand municipal water service to most of the affected homes there.
The Bennington Banner reported that if the deal is finalized, Saint-Gobain would provide roughly $26 million for water line extensions and for new wells, or long-term filtering for wells where water lines aren’t feasible.
The tentative plan includes up to $4.7 million in state funding from a revolving loan fund.
"This is a good day for Vermont and part of our larger effort to ensure safe drinking water for all Vermonters," Vermont Gov.
Phil Scott said in a Tuesday statement.
Saint-Gobain is considered by the state to be responsible for widespread water contamination with the chemical known as PFOA, a suspected carcinogen, around two former ChemFab Corp. factories in Bennington.
The company previously agreed to provide $20 million for water line work for about 200 properties on the west side of Bennington.
That work began in the fall of 2017 and is essentially complete.
The engineering and design for the new project is expected to be finalized next month.

The state of Vermont reached a tentative agreement with a plastics company to address chemical contamination in more than 150 private wells on the east side of Bennington, the state announced Tuesday.
The Agency of Natural Resources said an agreement in principal with Saint-Gobain Performance Plastics will expand municipal water service to most of the affected homes there.
The Bennington Banner reported that if the deal is finalized, Saint-Gobain would provide roughly $26 million for water line extensions and for new wells, or long-term filtering for wells where water lines aren’t feasible.
The tentative plan includes up to $4.7 million in state funding from a revolving loan fund.
A final settlement is dependent on ongoing engineering design work.
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Phil Scott said in a Tuesday statement.
The company previously agreed to provide $20 million for water line work for about 200 properties on the west side of Bennington.
That work began in the fall of 2017 and is essentially complete.
The engineering and design for the new project is expected to be finalized next month.

Workers from the Palm Beach County Parks and Recreation Department pick up dead fish from the Ocean Inlet Park in Ocean Ridge, Florida in October 2018.
Some beaches north of Miami were closed at the time because of a rare red tide outbreak along Florida’s Atlantic coast.
[Joe Cavaretta/South Florida Sun-Sentinel via AP] DeSantis is asking the Legislature to spend $625 million this year on water projects, the first step toward a roughly $2.5 billion, four-year investment in tackling problems plaguing Lake Okeechobee, nearby rivers and estuaries, freshwater springs and the Everglades.
Ron DeSantis on Tuesday began attempting to put dollars behind that pledge.
DeSantis is asking the Legislature to spend $625 million this year on water projects, the first step toward a roughly $2.5 billion, four-year investment in tackling problems plaguing Lake Okeechobee, nearby rivers and estuaries, freshwater springs and the Everglades.
DeSantis also began reshaping the South Florida Water Management District, whose nine-member board he wants overhauled, having demanded the resignations of current members.
In his budget proposal to the Republican-controlled Legislature, DeSantis is calling for increases in many areas of state environmental spending.
The governor also said the Department of Environmental Protection is seeking applicants for a nine-member, blue-green algae task force, proposed in his executive order.
DeSantis on Tuesday also said that DEP is looking for a chief science officer, another element of his executive order.
Getting the water right protects our future.” Lisa Rinaman, with St. Johns Riverkeeper, said she welcomed the new administration’s attention to sea level concerns.

Napier City Council spending almost $4000 per month dealing with brown water complaints Napier City Council is spending almost $4000 per month, on average, flushing out water pipes due to complaints about discoloured water.
Figures obtained under the Official Information Act show the average cost per month of flushing out water pipes has been $3875 in the 19 months between May of 2017 and November last year.
The highest number of complaints received in a month was 185, in December of 2017, while the lowest number was 16, received in March last year.
NCC says the discolouration is the result of "harmless biofilm" being washed out of the pipes during routine maintenance.
Christchurch City Council, which in March chlorinated its water supply for similar reasons to Napier, says on its website that "chlorine is a powerful oxidising agent".
"It might also react with iron in the old cast iron mains and it will react with any other organic material it comes across."
NCC maintained the discoloured water was purely an aesthetic issue and never expressly warned residents not to drink it.
Source: 1 NEWS After 1 NEWS ran a story about the results, the council continued to maintain it was safe to drink the water, but also updated their website, saying that "to have any health effects from drinking this water, you would need to ingest it frequently over a long period of time".
They also included advice from Dr Belinda Cridge, Programme Director of University of Otago’s Pharmacology and Toxicology Department, who recommended a precautionary approach for vulnerable groups who may drink the water.
The groups include infants, pregnant women and the elderly.