History. The other point that I'll draw attention to on this slide, other than the fact that I believe we're undervalued, it's a very small number of outstanding shares, right? In 2021, Doug and I were able to buy back a 60% block that was owned by a Chinese state-owned investor and retired those shares from $38 million down to $16 million. It just gives us a nice structure for the future, right? All right, what do we do? We talked about air emissions abatement. BioRem is short for bioremediation. In layman's terms, we harness the power of Mother Nature, right? We grow bacteria and fungus that actually eat air pollution as their food source. That's really the core of our business. However, not every application can be dealt with using biological solutions.
Over the last several years, which kind of coincides with our trajectory financially, it has been bringing in a full suite of technologies and services. We're kind of a one-stop shop these days, right? Full engineering from the front end all the way to the back end with performance verification. We provide capital equipment, so whether it's a physical, chemical, or biological solution, providing a reactor to deal with those air emissions. We're technology agnostic now, focusing on a wide range so that we're matching the right technology for the customer's needs. Where can this technology be used? Across a wide range of industries. What sets BioRem somewhat apart from a lot of other clean tech companies is our exposure to critical infrastructure.
If you look at the first two buckets here and arguably the fourth bucket, whether it's municipal wastewater, water treatment, or solid waste treatment, these are projects that are funded by the government, tend to have a lot of visibility, and tend to be recession-proof. Approximately, depending on the year, call it up to 75% of our business could be in the infrastructure space. It kind of gives us a little bit of a unique play on the clean tech side since the macroeconomic factors can have an outsized impact on a clean tech company, right? You can imagine in a period of economic downturn, a company will not invest typically into an environmental project. When you're dealing with infrastructure, people still need to put their recycling out on the curb. People still need to flush their toilets regardless of the macroeconomic conditions. It's a unique play with BioRem.
Our technology, however, can be applied across a wide range of other applications, whether it be pet food, chemical production. We've gotten into food and beverage, agriculture, semiconductor, and even surface coating. Anything that's biodegradable, essentially we can design a reactor to deal with those emissions. There we go. All right, what's our value proposition when it comes to our clients? We like to deal with very complex projects. Ontario has one of the strictest quality of life regulations on the planet. When we're talking about in Ontario, everyone has the right to be able to drive to school, to work, to be able to barbecue in their backyard without being exposed to noise or offensive odors. The regulations we've set in this province are extremely difficult. One odor unit is the target.
Now, to put that into context, if I exposed you all to a sample of air that had an odor intensity of one, half of you in the room would not smell anything. The other half would say, "Hey, I think I smell something," but you wouldn't be able to characterize that odor. Just giving you an idea of how stringent this is, right? When you fry bacon in your kitchen, that's probably 500, 600 odor units right there. Just trying to put this in the context for you. This is kind of where we grew up, I'd say, in parentheses here, as a company dealing with these very challenging technical issues. There are very few companies that excel and can back up their claims with actual data. We also love complex air emissions. You can imagine that certain processes emit a wide range of compounds, maybe 100, 200 compounds.
Some may cause cancer, others just smell. Essentially, dealing with a wide range of varied chemistry requires you having knowledge of that chemistry and what technologies can be used for each component of that mixture. That's another area where I think we really excel. Being able to back this up with a guarantee is also very important. We love the challenging projects. Those tend, coincidentally, to be the most profitable projects for BioRem. That was a quick little recap of who we are and what we do. The next little segment just talks a bit about, hey, how are we doing financially this year? How does that look? For those of you who are familiar with the BioRem story, our growth strategy was both organic and inorganic. Organic growth has been looking very good. We're on track for yet another year of continuous growth.
As usual, this is back half loaded, right? You can imagine on January 1, everyone jumps out of bed. Everyone in the project is trying to get the project completed as quickly as they can. That's all the stakeholders, whether it's the client, the consultants, the regulators. Everyone wants to get this project done. It just takes time to realize. As we look at our numbers historically, it's always back half loaded. This year is not going to be any different from the previous 10 years. Expect to see Q3 and Q4 look better than the first half of the year. Definitely, it's the new products and services that are driving the growth. I'll give you some stats on that shortly. How are we looking at it from a sales perspective? Sales drives revenue, which drives profits.
Bookings year to date, and these are just estimates right now, but over $40 million trending in the right direction. Our backlog breaking yet another historic record at over $70 million in hand. As a refresher, backlog is orders in hand. We have a 99.999% retention rate. It's not a matter of whether we're going to deliver the $70 million. It's when. Very good numbers, very pleased with that. The bulk of this is through repeat customers across the world, including the U.S.A., but some bright spots happening in the Middle East, as well as in Southeast Asia. That's been kind of driving those bookings. Over the last five plus years, the team has been delivering. You can see that reflected in our EBITDA growth, as well as obviously the EPS growth.
I like the shape of the curve, and we seem to be on that trajectory to continue that trend for the foreseeable future. What does that translate in terms of, you know, I talked about what was driving the growth. A couple of years ago, we introduced a full suite of physical solutions. Rather than bugs eating the air pollution, think of them as sponges, right? Big sponges soak up all that air pollution. Once the sponge is full, dispose of it. That was the first new product line we brought in. Chemical scrubbers just started last year, and noise abatement or sound attenuation also late last year. You can just see that by focusing on those dry scrubbers, focusing on these new products, these are significant numbers. Part of the business, we're capital equipment, very lumpy, right? Quarter to quarter, it's always outside of our control.
If the facility hasn't been constructed yet, they're not ready for our equipment. One of the things management's been working on is how can we diversify the revenue streams to get a nice foundation of recurring revenue? What better foundation but using your existing customers? Over 2,500 installations globally, that's a great pool to go after. In the last 18 months or so, I've been really focusing on trying to build out our service group, focus on this business to kind of smooth out the peaks and valleys from quarter to quarter. You can see with phenomenal success this year in the service side. What does this mean in terms of the product mix? We're doing roughly a third of our business of all new bids is coming from this bucket of new products and services. Very pleased with the progress on the organic growth.
That's all in the background, right? That's behind us. What are we doing to go forward? What does the market look like for BioRem Inc.? Why do I think BioRem Inc.'s well poised to take advantage of that? We still have a large number of very positive market drivers, right? Immigration gets a bad rap these days. If south of the border, you know, the border might actually be closed, but you're still having a lot of internal migration. Canada still has still very high immigration from external sources. We're still experiencing a lot of migration. In the U.S., for instance, you've got large numbers leaving California, going to Texas. In Canada, you're still seeing a lot of stuff move west from the east as well. Every time you've got people moving and you've got housing shortages, you need new units to be built.
That means new toilets, new garbage routes, new recycling routes. Certainly, this internal, external migration, as well as the housing issues, still creating a market driver moving forward. Looking at infrastructure, a lot of demand on infrastructure. To deal with the capacity of new people moving into new areas, you need to expand those facilities. Certainly in Canada, we have a lot of installations that are quite old. In other jurisdictions, certain jurisdictions in the Middle East, a lot of the communities each have their own small wastewater treatment facility where there's a movement for scale of size and cost reduction to actually aggregate these smaller municipalities into massive, larger regional plans. Anytime you've got an upgrade occurring to an infrastructure, that creates a demand for air emissions abatement as well. Furthermore, on that side is the regulations. While air tends to be not as regulated, right?
If it's odorless, it doesn't have any color, no one sees it, it takes years before those problems become apparent and get addressed. When you're dealing with water, people notice right away if the creek is blue or green, right? Discharge limits continually get more strict, and it's something that communities can witness right away. As we see these discharge limits going down and these regs focusing on new components, you're seeing an investment in infrastructure to deal with that. Once again, that creates demand for our equipment. Finally, the last bucket of the drivers on the community side, right? You've got dense urban communities that are only getting more and more vertical, more and more people. You've got infrastructure industry and residential areas all coexisting. That creates a demand for quality of life, right? Noise, odor, and emissions. You're also having a higher public awareness.
Awareness of the rights of the regulations and awareness in a lot of communities also just taking a more holistic view and looking at lower carbon footprint solutions, where harnessing bacteria to do the work for us kind of fits all of those categories. From a macroeconomic standpoint, we still see the same drivers and we don't see any abatement at this current time for any of those drivers. In terms of overall markets, air pollution control or odor control, the numbers are still staying fairly consistent year over year as we look at various publications. I throw these numbers out very cautiously, not for you to focus on the actual large annual expenditure, but really about the potential for growth. The addressable market in the U.S. annually right now is roughly $1.1 billion. That's across every industry, right?
About a third of that will be just on combustion sources from power plants, power generation. You can kind of factor that down. BioRem Inc. currently operates in a segment of that $1.1 billion that's probably between $200 million and $300 million, just to kind of put it in place. What's also important to look at on these numbers is really at that growth rate. If you look at North America, across all segments, you're looking at roughly a 6% growth rate. The municipal, the infrastructure segment's growing at a much faster rate because of all those macroeconomic factors. That greater rate is probably getting close to the 10% annual growth rate, which lo and behold kind of coincides where BioRem's growth rate currently is with the full range of products.
I focus more on the future potential in terms of the addressable market with what we have now and how that's just growing on its own. I also look at the other parts of this pie as BioRem grows and expands into other segments of what may be possible in the long term. Right now, we're focused on that small piece of the pie as it's the lowest hanging fruit. What are we going to do to achieve or to maximize these macroeconomic factors and this opportunity? We're staying with the same strategy we've employed for the last several years. It's kind of in two parts: organic, continue with the new product introductions. We've got a lot of ground still to cover with the noise abatement, with the chemical scrubbers, even with the dry scrubbers, still a lot of room to grow there.
The service group expansion, like I said, we didn't have a fully dedicated structure within the organization to address that opportunity. This year, we've taken one of our Senior Project Managers. He's transitioning to be the head of this new business unit, the service group. We've hired coordinators. We've hired field service people. We hope that the investment in people and the strategy we're looking to execute in the service group will pay off in the coming periods. It already has with almost $10 million in sales this year, which is a significant chunk of our sales. We're also continuing on the organic side. We're investing in our sales, the next generation of Sales Managers. We've brought two of our Senior Applications Engineers that are quite personable, that we believe is the right way to go in terms of building out a technical sales team.
That almost doubles the size of the sales team. That'll pay off in the coming years. Finally, the inorganic strategy, right? Doug and I are not here for financial engineering. You've heard me say this time and time again. Any transaction we do is going to be creative and it's going to add value to the organization, right? We're not here about just bolting together some pieces that don't necessarily go together. We're disciplined. We're taking an approach to make sure that we get the right transaction completed and create that value. It's all across the board, whether it's technology, whether it's rolling up the competition, whether it's buying customers in new markets. I think on that slide, I will wrap up a few minutes early because we already have early takers for the questions.
OK, Doug, you addressed at the beginning of the conversation that you had bought back 60% of the shares, all right? I would like to know what price did you pay?
We paid, I think it was just roughly $0.51 at the time.
Oh, my.
Plus or minus $0.005. It's right in that area. This was a block. When the company went public in 2005, a clean tech fund out of New York through expansion capital had a 60% block. Twelve years later, they wanted out. They wanted to close this fund, wanted out. At the time, management was looking at a lot of different options that we didn't believe in. We thought the company would do better. We found a Chinese. I was in China at the time setting up companies. We found a Chinese state-owned investor. It was supposed to be a strategic investment by them. They had hundreds of facilities that they were going to use our systems on. We ended up doing three. They never paid for it. It was a nightmare dealing with this for four or five years.
We were able to figure out a way to repurchase that 60% block. Since that time, we've been able to focus on what we do best. That's kind of the trajectory of how that happened. We were trading at roughly $0.10, $0.15 at the time. When I structured the deal with the Chinese, we did it at $0.345. When we bought them back, it was roughly $0.51. I think overall it was a good deal for expansion. They got the best deal they could have gotten at the time. I think the Chinese state-owned investor made some money off it. I think it was fair value for BioRem Inc. because certainly the share value has increased steadily since then.
Thank you.
Any other questions? Yes, sir.
The market potential over $1 billion, right? Why not your high sample?
Why not make it bigger?
Yeah.
I think.
Looking for business?
Yeah, that's a good question. I think, you know, sales in our industry take anywhere from one to 10 years, right? It's a very long sales cycle. You can imagine if you're building a billion-dollar plant upgrade, it's going to take time for that cycle to happen. It's a massive investment into a sales force until you see the results of that. It's a fine balance of trying to do more with what we have and building out the team without negatively impacting the financial statements. Remember, got to be a little cautious with that billion because I'm only working and we're really operating in a $200 to $300 million. I do want a bigger share of even that part of the pie.
Yeah, you mentioned the stringent regulations in Ontario, but there's often a gap between regulation and enforcement.
Enforcement, yes.
Can you tell us who is ready to pay to clean up Sarnia?
That I can't answer. Very good observation on regulations and enforcement. That's one of the reasons why working in the U.S. and Canada is a good thing. The enforcement is usually quite high. In many applications, when it comes to infrastructure, even if there is no federal, state, or provincial regulations, the municipality will go above and beyond because they're the ones that have to deal with those issues. From a North American perspective on the infrastructure side, we're seeing that demand go regardless of the regulations and the enforcement. In terms of Sarnia, I can't answer that part of the question. We're working on it, one job at a time.
Sure. Thanks. Just a quick question on your M&A strategy. You talked about doing accretive transactions. You put up different TAMs there. Where are you focused right now and what kind of opportunities are you looking at? Are they in similar markets or adjacencies?
Both, all of the above. We operate in a bit of a niche market, right? Once again, I prefaced that part of the discussion by saying we don't want to do a deal for a deal's sake. Certainly something in the industry, adjacent to the industry. We're looking for it to be accretive ideally. Also looking to have a good team, right? In this day and age, finding good people and skill sets is a challenge. Certainly looking for a company that has a lot of these elements. Doug and I have not been shy about looking at any good deal that's out there. We really do want to be able to add value, share the culture with the management teams, and to be able to grow something from there.
One of the fairly large swath of segment that we're looking at that makes a lot of strategic sense for BioRem Inc. is anything being sold on these infrastructure projects, right? Whether I'm selling a biological system, whether I'm selling a chemical system, or I'm selling the noise abatement that could go with it or another part of the plant, the whole ecosystem is the same. From regulators to the consultants, to the end users, to the contractors, to the supply chains, this becomes anything within that vast realm becomes very cost-effective for us to integrate and to gain market share. That would be an ideal focus. After several years, Doug and I have looked at over 200 companies. We've made it to due diligence on a dozen. There's not that many companies out there to look at, especially ones that are profitable.
OK, thank you.
Any other questions? No, that's good. One more. You can try one.
In old times, some river, like Detroit River, between Rings and Detroit, before no fish, now they have fish, right? It's getting cleaner. This summer I went to London for the UK. That river is so dirty, no fish. Can you do something for them, get some business?
Not at this point. We're focused on gaseous phase rather than liquid phase, but maybe someday in the future.
Last one. What percentage of your revenue now is aftermarket? What's reasonable that you could grow that to based on this type of business?
Excellent questions. The $9.9 million that I mentioned for this year is a bit of a peak, right? Right now, between a 12-month period from today to 12 months from now, it could be as much as a quarter to a third of our revenue. I think if I take the noise out of this, right now we're probably sitting more around the 5% to 10% of our revenue is service. I'll give you an idea of one segment alone. We talked about these sponges, right? The physical systems. It's estimated in the U.S. there's over $200 million annually of replacing that material. Can we get access to all of that? Probably no. There are some bigger companies that can get access to it. If you get into the way these municipalities do it, they may have 10 sites. At these 10 sites, they may have 20 of these sponges.
They don't just go out for each one individually. They put out multi-year contracts. These contracts, Minneapolis, we just bid one, was $3 million U.S. a year. It was a five-year contract. We won one. Our first one that we won was for Victoria, BC. It's $600,000 a year for four years, renewable after four years. If every municipality has these, that segment of the service business alone is fairly substantial and certainly one of the areas we're trying to focus on. Wrapping it up. All right. Thanks for everyone's attention.