Top hotels and restaurants worldwide are adapting their water service practices.

At Singapore's three-Michelin-starred Restaurant Zen, you can request a bottle of Evian or San Pellegrino.

But you won't get one.

Executive Chef Martin Öfner stated that the restaurant, which has a nearly $500 per person dinner charge, exclusively uses water from Nordaq, a Swedish company.

The restaurant's dishes and drinks are made from water, including its stocks and non-alcoholic beverage pairings, he stated.

Nordaq water, which is purified and bottled on-site using local tap water, is served at more than 140 Michelin-starred restaurants and is also present in over 700 luxury hotels, casinos, and cruise ships, according to CEO Johanna Mattsson of the company.

The hospitality industry aims to reduce the use of single-use water bottles, including both the inexpensive plastic ones commonly found in hotels and the expensive glass-bottled European mineral water served in high-end restaurants. These bottles can travel thousands of miles from their source to their final destination.

"Mattsson stated that the transportation of water over water is illogical and should be eliminated."

She stated that Nordaq's bottles are free of plastic labels, allowing for easy washing and reuse, and they have wide mouths for cleaning in standard dishwashers.

Mattsson stated that bottles are securely capped and date-stamped after they are refilled.

Since 2023, Nordaq's water system has been available at Mandarin Oriental Singapore, with bottles provided in the hotel's rooms, restaurants, spa, and gym.

Cindy Kong, the Hotel Manager, allowed CNBC Travel to tour the bottling facility to observe the process of washing, inspecting, filling, and sealing the bottles. She stated that the facility has the capability to produce 500 bottles of purified water per hour.

She stated that they typically handle between 1,000 to 2,000 bottles daily.

While Nordaq is one of many companies in the premium sustainable water business, Castalie water is present in more than 700 hotels in France, and Purezza water is served in more than 5,000 venues across 13 countries.

In July, ITC Hotels' New Delhi branch, ITC Maurya, shared on Facebook that they created their own brand of "zero-mile" water called SunyaAqua to reduce single-use plastic bottles in their 140 hotels. Every guilt-free sip is bottled in-house, eliminating the need for transport.

Be WTR's core market is hospitality companies, with a facility set to open in Rosewood Abu Dhabi and centralized operations.

Mike Hecker, founder and CEO of Be WTR, stated that although ITC Hotel's "zero mile" water may travel slightly farther, the difference is not significant.

""Our carbon footprint is highly impacted by transport, which is why we prefer to be located at the point of consumption as much as possible," he said to CNBC."

The company's primary operations are in the United Arab Emirates, but its water is sold in 12 countries, including recent expansions into Canada and China. The company raised $44 million in Series C funding in October.

Accor has signed a global agreement with WTR to be a preferred partner for its luxury hotel brands.

"We are the first company to have a global water agreement targeting Accor's five-star brands, including the Raffles, Pullman, and Sofitel," he stated.

Less waste, higher profit

No- or low-transport filtered water suppliers in the tourism and food industries claim to save millions of plastic bottles annually, but they also offer a profitable opportunity for their clients.

WTR's Hecker stated that its first bottling plant at Westin Dubai Mina Seyahi reduced "over one million imported bottles a year." This accomplishment is significant in terms of both carbon footprint and generating positive profits for the client.

Hecker refused to reveal the price of a Be WTR bottle, but stated that it is competitively priced compared to European glass-bottled mineral water.

Nordaq's Mattsson reveals that each bottle of its water costs between 11 cents and 21 cents to produce. However, the water is sold for a much higher price. The Providore Singapore offers free-flow still and sparkling Nordaq water for $2 per person, while some luxury hotels charge four times that amount for a single bottle.

Purezza water costs around $5 per bottle to produce, which is one-fifth the price of regular bottled water, according to the company's sales brochure. Despite this, both types of water can be sold for the same price, with the brochure estimating that 1,000 bottles of Purezza water sold at $5 per bottle could generate $13,200 in annual profit for the seller.