The breweries and pubs group committed to zero waste to landfill by 2020 and starting from around 70 per cent has already achieved 99.5 per cent.
Group energy manager Chris White said the 0.5 per cent was a negligible amount and represented material that could not be disposed of by other means, such as asbestos.
"Achieving more than 99 per cent is classifield as 'zero waste'," he explained.
A series of environmental initiatives have also been implemented across the business's six breweries and more than 1,500 pubs and restaurants across the UK.
Minimising waste and recycling are at the heart of the Marston's policy.
"Our goal is to become the most environmentally efficient large hospitality company that is out there. We are well on the way to that.
"We have changed the wider model of how we look at waste services. It has allowed us to be more flexible in controlling where waste goes," said Andy Kershaw, head of group facilities,
"We are working with suppliers to avoid putting waste to landfill sites. Recycling is the best option or going to energy recovery through anaerobic digestion plants."
The greening of Marston's has seen sites where it previously had six to eight general waste bins down to just one.
Under the guidance of the three-strong energy team of Mr Kershaw, Mr White and Jon Davies, waste and recycling co-ordinator, the business recognised an industry need for more sustainable solutions as a major pub company in the hospitality sector; an industry that creates over 60,000 tonnes of waste a year.
Since 2016, the team, on behalf of Marston’s, have been working in partnership with UK Waste Solutions to help implement innovative sustainability solutions that have both long term environmental and financial benefits to operations.
The initiative is already delivering significant savings – into the millions – for the business including reducing landfill tax and commercial waste collection bills.
Mr Kershaw said that Marston's had gone from a recycling rate of 60 per cent 18 months ago to 77 per cent and the target was to improve that to more than 90 per cent as part of the 2020 Challenge.
The Victorian Park Brewery in Wolverhampton, home of Banks's, is achieving 100 per cent.
Among the measures in place are sending cooking oil for refining to produce biodiesel.
A new step has been investing in cardboard bailers to compact things like packaging ready to send off for recycling.
Marston's is also engaging with suppliers to reduce the amount of packaging coming to its sites and making sure what comes in is suitable for recycling.
Mr Kershaw said the group was now working on how to reduce plastic including replacing plastic rings on six packs of beer cans with cardboard.
The Sun, a traditional pub at Romsley, near Halesowen, was the first where Marston's has used plastecowood, a material made from plastic waste.
Plastic from the site has been utilised to make garden furniture and decking for the large garden area at the popular pub near the Clent Hills. The work was done in July.
"We have already taken action on plastic straws, moving to supplying them only on request since January.
"There has been a reduction of 81 per cent since then," said Mr Kershaw.
Mr White said it was also looking at an environmentally-friendly solution to replace them completely.
Mr Kershaw said that Marston's had achieved results more quickly than other companies.
"One benefit was that people have become so used to recycling at home that they could relate to it easily within the business. The changing processes and procedures were what they were doing automatically at home."
"The impact of the Blue Planet also meant people picked up on the need to reduce plastic and increase recycling," said Mr White.
Mr Kershaw said the initiative had been backed across the group all the way up to board level and chief executive Ralph Findlay who had been delighted with the success.
Alongside waste reduction there has been an emphasis on energy efficiency and carbon reduction.
Every new building over the last five years, including the new Marston's House headquarters in Wolverhampton, which opened in March 2016, and its latest pub/restaurants and lodges has had the latest energy efficient technology incorporated including LED lighting
"We are pretty much industry leading in terms of energy efficiency and are constantly reviewing the model to look at ways to make our operation more efficient.
"We have the most efficient new build estate in the industry," said Mr Kershaw.
Marston's has also been improving energy efficiency across its older estate with LED lighting now in all internal areas.
Steps have also been taken to cut bills on water.
Last year the group became one of the first in the industry to go down the self supply route to become a water supplier.
It now supplies water to all its pubs and the measure has enabled it to drive efficiency in water usage across its estate.
"It has achieved savings and meant we get significantly more accurate bills. "
It was only the third UK company to secure a licence to supply its own water and wastewater services from water watchdog Ofwat
The use of energy throughout the business has been re-evaluated over the past few years triggered by increases in energy costs, regulation and a new awareness of opportunities for improving energy efficiency.
UKWSL’s managing director Max Kanda said: “Marston’s vision and commitment to developing a more sustainable business model has helped position them at the forefront of the hospitality sector. We look forward to continuing to work in partnership with their team in order to change attitudes from waste to resources and develop increasingly circular solutions for these materials, which optimise both their commercial and environmental value.”
The partnership between Marston’s and UKWSL is part of a wider drive for sustainability solutions across the business.
On top of the success of Marston’s operating at zero waste to landfill, Mr White has been named in the exclusive EDIE’s Top 100 Energy Leaders, a group that celebrates the best in-house energy managers, the collaborative group host conferences, talks and share insights and developments to set standards for energy efficiency across UK businesses.
Mr White said: “To be named as one of the Top 100 Energy leaders not only in the hospitality sector but across all industries is amazing. The team and I have made some big changes for Marston’s that have demonstrated innovation and business leadership for our industry, so I am really proud that the work has been recognised by key figures and EDIE.”
Using the team’s knowledge and best practices in energy and sustainability for Marston’s, Mr White and the team are due to take part in the Carbon Reduction Forum, hosted by the Carbon Statement followed by the inaugural industry briefing for the Top 100 Energy Leaders on September 13.
Marston’s has an estate of 1,568 pubs across the mainland UK comprising of managed, franchised and leased pubs. It operates 400 destination pub restaurants and employs around 14,500 people
It is the UK’s leading brewer of premium cask and packaged beers including Hobgoblin, Pedigree, Wainwright and Bombardier along with many regional favourites and a range of licensed brands including Youngs, Founders and Estrella Damm.