Palestinian farmland around the West Bank town of Qalqilya is being poisoned by industrial sewage pumped from nearby Jewish settlements, according to a recent report by Israeli newspaper Haaretz.
Many settlements lack adequate waste disposal facilities
About 200 olive trees have already died from the contamination.
Qalqilya's problems highlight the fears of both Palestinian and Israeli environmentalists that Jewish settlers are regularly polluting the land, air and water of the occupied territories.
In the West Bank village of Beit Duqqu, residents complain that neighbouring Jewish settlements have been polluting their farmland for around 15 years.
And a kilometre outside the village stands a huge pile of their own rubbish lies smouldering half-burnt.
The refuse is dumped and burnt there - next to ancient Roman ruins - because Jewish settlers in nearby Hadasha settlement demanded that Palestinians stop using a more suitable site which necessitated them passing close by the settlement, Beit Duqqu residents say.
Villagers also say children have fallen ill after swimming in a local stream polluted by untreated sewage pumped from another settlement high on a nearby hilltop - Givat Zeev.
Farmers complain that the sewage washes through the area when it rains, attracting insects that eat their crops and making animals sick.
"It's had a big impact on my livelihood," said local farmer Farouk, "I've had to use lots of my savings to buy insecticide and each year the problem is getting worse"
The villagers say they have tried to meet the settlers to resolve the problem.
"We tried to make three or four meetings with the leader of the settlement but he refused to talk about it and said 'we don't care'," says Beit Duqqu community leader Akrima Ray.
Environmentalists maintain that the Israeli authorities are not doing enough to prevent pollution in the West Bank.
In April, Israel gave the go-ahead to settlers to convert a former Palestinian quarry into a dump for industrial waste from Israel and Jewish settlements in the West Bank.
Around 10,000 metric tons of waste are set to be dumped at the site each month.
Settlement sewage often flows untreated onto Palestinian farmland
A 2004 report by Friends of the Earth Middle East found that only 6% of Israeli settlements adequately treated their sewage.
The settlers account for only 10% of the population of the West Bank, yet produce 25% of sewage pollution, the study found.
The group also found that sewage from settlements was polluting the underground water aquifer that serves both Israel and the West Bank.
The Israeli Ministry of the Environment which is responsible for enforcing environmental standards in Israeli settlements only took steps against 14 of more than 60 colonies illegally discharging sewage, the FOEME report says.
This is partly due to the difficulties of enforcement in areas under Israeli military control.
Yet some measures have been taken against the West Bank's largest settlement, Ariel.
According to environmentalists, criminal proceedings were launched against Mayor Ron Nachman over the lack of sewage treatment facilities serving the town.
He faces a large fine or personal imprisonment and there are now well advanced plans for a sewage treatment plant in Ariel.
Palestinians are also responsible for a share of the pollution
Despite this, the mayor recently criticised Palestinians on their own environmental record.
In a letter to Israeli Prime Minister Ariel Sharon and Friends of the Earth he cited possible Palestinian pollution of Gaza as a reason for the government to abandon its controversial plan to disengage from the area.
The settlers themselves say they have taken their own measures to protect the environment.
The Municipal Environmental Associations of Judea and Samaria was set up by settler councils to promote environmental awareness in the West Bank.
Their stated goals include a commitment to find solutions to sewage treatment problems and to work with the Palestinian Authority on environmental issues.
They also require environmental impact surveys be carried out on new building by settlers in the West Bank.
The Palestinian Authority itself has also been targeted by environmentalists for not doing more to prevent water pollution, despite the difficulties posed by the security situation.
Campaigners are calling for the PA to raise awareness of environmental issues as many Palestinians dispose of their sewage in cesspits that leak into the water table.
It is not just the settlers homes that are a source of pollution in the West Bank.
The industrial and manufacturing businesses that they operate are also a source of pollution, Palestinian environmentalists say, as many do not conform to Israeli standards.
According to environmentalists Barkan industrial zone, close to Ariel settlement, is responsible for producing untreated sewage and solid waste that is then buried on Palestinian agricultural land.
"We have no problem working with people living in Israel but the settlers have a different mentality," says Dr Nadil Khateeb of the Water & Environmental Development Organisation in Bethlehem.
He fears that the settlement industries could cause serious health problems among Palestinians in the future.
"Industrial waste can contain heavy metals, you only need a small amount to pollute a water supply and that could cause cancers."
"The problem is definitely getting worse because nothing on the ground has changed."