Harpur Hill Quarry facts for kids

Quick facts for kids Harpur Hill Quarry Lagoon
The quarry's lagoon in May 2012
Harpur Hill Quarry Lagoon Location in Derbyshire
Location	Harpur Hill
Coordinates	53°14′01″N 1°54′15″W / 53.2336°N 1.9043°W / 53.2336; -1.9043
Lake type	artificial
Primary inflows	groundwater
Primary outflows	evaporation, seepage
Basin countries	England
First flooded	c. 2005
Max. length	308 ft (94 m)
Average depth	2 m (6 ft 7 in)
Max. depth	3 m (9.8 ft)
Settlements	King Sterndale, Buxton

Harpur Hill Quarry is an old limestone quarry in Harpur Hill, England. People dug out limestone here from 1835 to 1952. This limestone was used to make a material called quicklime in special ovens called lime kilns.

During the Second World War, the quarry became a huge storage place for chemical weapons for the Royal Air Force (RAF). It was the biggest such depot in the United Kingdom. After the war, some captured German chemical weapons were burned here to get rid of them. However, this didn't work very well. The RAF depot closed in 1960, and the site is now empty.

A small part of the old quarry has filled with water, forming a quarry lake. This water is very alkaline, meaning it has a high pH level. This is because of strong chemicals left over from making quicklime. The lake water is a bright blue colour. This blue colour comes from tiny bits of calcium carbonate floating in the water.

Even though there are signs warning people about health dangers, the lake became a popular place for tourists and swimmers. To stop people from swimming, the local High Peak Borough Council has dyed the water black several times.

History of the Quarry

The area near Harpur Hill, south of Buxton, has been a place where limestone was dug out for a long time. People started making quicklime here around the 1600s. They used lime kilns to heat limestone, which turns it into quicklime.

A larger quicklime factory was built next to the quarry around 1835. It operated until about 1952. Big companies like Brunner Mond and later ICI ran this factory. The large oven they used, called a Hoffmann kiln, was taken down in 1980. This made space for new buildings.

Making quicklime created a lot of waste. This waste was dumped nearby, forming big piles of dirt. These piles had quicklime and ash from the coal used in the process. When rain or groundwater goes through these waste piles, it picks up chemicals like calcium hydroxide. This makes the water very alkaline.

The Quarry as a Military Depot

In 1938, the Royal Air Force (RAF) took over the site. They wanted to use it to store chemical weapons. Building the depot took longer than planned because of bad weather. It finally started working in 1940.

During the Second World War, this depot was the largest place in the country for storing chemical weapons. It covered a very large area, about 500 acres.

After the war, an RAF team worked at the site. They were in charge of getting rid of unexploded bombs and captured German chemical weapons. This included warheads from V-rockets. The RAF tried to destroy chemical weapons like mustard gas and phosgene by burning them with bleach on the nearby hills.

However, this method didn't work well. It created a lot of smoke, and the weapons weren't fully destroyed. Some mustard gas escaped as a gas, which killed much of the plants nearby. The site also had an RAF Mountain Rescue team. They helped with plane crashes in the Derbyshire area. The RAF depot closed down in 1960.

The Blue Lagoon

A quarry lake at the site became a popular place to visit. It is officially called Hoffman Quarry, but many people know it as the Blue Lagoon. It attracts visitors from all over the country because of its bright turquoise-blue colour.

The blue colour comes from tiny particles of calcium carbonate that are forming in the water. The quicklime that dissolved in the water makes it very strong. The water has a pH level of 11.3, which is very alkaline. To compare, bleach has a pH of 12.3.

Safety Warnings and Council Actions

Signs at the quarry warn people about the dangers of the water. They say the water can cause "skin and eye irritations, stomach problems and fungal infections." The signs also mention that old cars, dead animals, and rubbish have been found in the quarry. The water is also extremely cold. Despite these warnings, many people continued to visit and swim in the lake.

About 750 local people were worried about the health risks. They signed a petition asking for the quarry to be drained and closed off. However, the water was too toxic to drain. Draining it would risk polluting local water supplies.

To stop people from swimming, the High Peak Borough Council decided to dye the water black in 2013. They did this because they couldn't get in touch with the quarry's owner. The black dye faded by 2015, and the water turned blue again.

The council dyed the lake again in 2016 with a stronger mixture. But by October 2019, it started to look blue once more. In March 2020, the lake was dyed black again. This happened after reports of people gathering there, even though the government had asked people to stay home because of the COVID-19 pandemic.

The council and Derbyshire Fire and Rescue dyed it again on May 29, 2020. This was after many people went to the site during a public holiday weekend. The police also blocked off parking spots in Harpur Hill. People still kept visiting the site. So, on June 19, 2020, local farmers tried to stop them. They spread pig and cow waste on the land around the quarry.