The growing popularity of DIY, encouraged by an "explosion" in daytime TV programmes on property, is leading to raw sewage being increasingly pumped into Britain's rivers, killing wildlife.

Botched plumbing jobs mean that foul water that should be piped into the sewage system is being fed into ground and coastal waters. According to the Marine Conservation Society, the growing problem is causing the degradation of the country's smaller rivers and threatening invertebrate ecosystems and depleting fish stocks, including salmon, trout, perch and pike.

Thames Water alone believes that in its region – serving 14 million customers in London and the Thames Valley – one in every 10 homes now have misconnected drains.

The government's refusal to set a 2030 target on decarbonising power generation and the "political vilification" of renewable power is deterring investment in the UK's energy infrastructure, the chief executive of the world's biggest wind power company has said.

Ditlev Engel, chief executive of Vestas, wrote in a comment for the Guardian on Thursday: "The failure to establish a firm 2030 power sector carbon cap prolongs uncertainty for the supply chain where investment time horizons extend well beyond 2020. This is a significant missed opportunity. Over the last year the onshore wind sector has been politically vilified. Such attacks add to the political risk attributed to the entire UK wind industry."

Organisers of BIG Green Week, the UK’s international festival of environmental ideas, art and culture, have confirmed that the nine day festival will be back in Bristol from 15th to 23rd June 2013.

Visitors can expect some heavyweight environmental talks, discussions and workshops as Jonathon Porritt, one of the UK’s leading environmentalists, curates his second year as Festival Chair. With the likes of Kevin McCloud, Vivienne Westwood, Bill McKibben, Caroline Lucas, Rob Hopkins, Tony Juniper, Prue Leith, Tim Smit, and Polly Higgins as guests in 2012, tickets are sure to sell fast again when they go on sale in the New Year.

The Lake District national park has added its huge clout to growing concern that nuclear waste burial in Cumbria is a dangerous and economically damaging non-starter.

The park's governing authority has written to the Department of Energy and Climate Change (Decc) minister responsible for nuclear waste, warning for the first time that fears about losing nuclear industry jobs in the region need to be balanced by potentially disastrous effects on tourism.

The move follows two public meetings in west Cumbria last week which heard from geological experts that a "cracked and leaky dish" was the best that the area's complex rock strata could provide to store material with a radioactive life of hundreds of thousands of year.