Good morning, and thank you for joining the Tetra Tech Earnings Call. By now, you should have received a copy of the press release. If you have not, please contact the company's corporate office at 626-351-4664. As a reminder, Tetra Tech is also simulcasting this presentation with slides in the Investor section of its website at www.tetratech.com. This call is being recorded at the request of Tetra Tech, and this broadcast is the copyright property of Tetra Tech. Any rebroadcast of this information in whole or part without the prior written permission of Tetra Tech is prohibited. With us today from management are Dan Batrack, Chairman and Chief Executive Officer, and Steve Burdick, Chief Financial Officer. They will provide a brief overview of the results and will open up the call for questions.
I'd like to direct your attention to the safe harbor statement in today's presentation. Today's discussion contains forward-looking statements about future growth and financial expectations. Actual results may differ significantly from those projected in today's forward-looking statements due to various risks and uncertainties, including the risks described in Tetra Tech's periodic reports filed with the SEC. Except as required by law, Tetra Tech takes no obligation to update its forward-looking statements. In addition, since management will be presenting some non-GAAP financial measures as references, the appropriate GAAP financial reconciliations are posted in the Investor section of Tetra Tech's website. At this time, I'd like to inform you that all participants are in listen-only mode. At the request of the company, we will open up the conference for questions and answers after the presentation. With that, I would like to turn the call over to Dan Batrack. Please go ahead, Mr. Batrack.
Great. Thank you very much, Laura, and good morning. Welcome to our Fiscal Year 2022 First Quarter Earnings Conference Call. We had an excellent first quarter and an exceptionally strong start to our 2022 fiscal year. Our performance resulted in record first- quarter revenue, operating income, and earnings per share, and a 120 basis point expansion in our collective operating margin. This extraordinary performance is a direct result of our long-term strategy to grow our high-end services, which is defined by our Leading with Science approach applied to our water and environmental markets. Given the strength of our performance and our outlook, we're increasing our guidance for both net revenue and earnings per share for fiscal year 2022.
I will begin today with an overview of our performance and customers, followed by Steve Burdick, our Chief Financial Officer, who will provide a more detailed review of our financials and capital allocation. After Steve, I'll then address our customer outlook and our updated earnings guidance for fiscal year 2022. In the quarter, we hit all-time first- quarter highs for revenue, operating income, and earnings per share. Our revenue increased by 12% year-over-year from $605 million to a new all-time high for a first quarter of $679 million. Our operating income increased at more than double the rate of our revenue growth, and our operating income was up 25% from last year, reaching a record $83 million for the quarter.
Finally, we delivered $1.19 in adjusted earnings per share, the highest quarterly earnings per share of any quarter in the company's history, and up $0.14 from our previous high record earnings per share of any quarter. I will note that on a GAAP basis, our quarterly earnings per share was even higher, at $1.25 per share, up 30% year-over-year, which Steve Burdick, our CFO, will address later on this phone call. I'd now like to provide an overview of our performance by our end customer in the first quarter. We saw continued strength in our state and local revenues, which were up organically 29% from the first quarter of last year. Even excluding the contributions of our disaster response work, this is another quarter of double-digit growth rate for our state and local municipal water businesses.
Our second fastest growing client sector was international, where our net revenue was up 20% from last year. Our international revenues benefited from the addition of our new high- performance buildings group in the United Kingdom, Hoare Lea, who joined us in the fourth quarter and contributed about half of our international growth rate. The rest of our international work grew organically at a strong year-on-year pace with the expansion of broad-based sustainable infrastructure programs in Canada, Australia, and in the United Kingdom. Our U.S. commercial net revenue was 21% of our business, up 7% from last year. Our services and sustainability, including those for environmental permitting, high- performance building designs, and renewable energy services, all contributed to growth in this sector. Work for our U.S. federal clients was 28% of our net revenues in the quarter and was stable from the same quarter last year.
Although our civilian and our Department of Defense work increased during the quarter, this growth was offset by reductions that we saw with the U.S. Agency for International Development-related work associated with the rapid wind- down and exit of the project work that we had in Afghanistan. I'd now like to present our performance by segment. Both of our business segments grew their revenue while expanding their margins from last year. The Government Services Group, or our GSG segment, was up 7% year-on-year, and that was based on challenging comparisons while delivering a very strong 14.7% operating income margin, which was up 70 basis points from last year. Our GSG performance was driven by our high-end data analytics and digital consulting and engineering services for water and environmental programs.
The Commercial International Group, or CIG, grew by 17% year-over-year and increased margins by 100 basis points from last year. The CIG margin expansion was directly in line with our strategy to continue to expand our high-end commercial sustainability services while increasing margins in our international operations. Our backlog was up 8% year-on-year on strong, broad-based orders, resulting in $3.45 billion of contracted, funded, and authorized work here in the company. We did see the U.S. dollar strengthen during the quarter, so if evaluated on a constant currency basis, just from the beginning of the first quarter, our backlog would have been up, not only up year-over-year, but up sequentially also to an all-time high for the company.
In the first quarter, we won new programs and task orders across our global businesses that are a direct result of our strategic focus on our clients' most highest priority programs that they have. Building on our expanded presence in the U.K., we were awarded a large $2 billion public framework contract. Notably, Tetra Tech was the only firm that was awarded a position in all six scope areas. We were also awarded a $24 million contract for our U.S. international development work that advances carbon mitigation and biodiversity. For the U.S. Environmental Protection Agency, they've issued us new task orders for high-end water and environmental services through our watershed and science and technology contracts. Now I'd like to turn the presentation over to Steve Burdick to present the details of our financials for the quarter.
Hey, thank you, Dan. I'd like to now review the GAAP financial results for the first quarter of 2022. Overall, as Dan noted earlier, we had record Q1 results for revenue and earnings. We had very strong top- line growth with first- quarter revenue of $859 million. The net revenue amounted to $679 million, which was at the upper end of our guidance range of $630 million-$680 million. Our revenue and net revenue were both up 12% over last year, with strong growth from state and local, international, and commercial markets. Our operating and financial results are the highest of any first quarter. Our operating profit and earnings per share for the first quarter increased over last year, also.
GAAP EPS came in as $1.25 in the first quarter, which is an increase of 30% over last year. The higher EPS was due to the increase in reported operating income, which came in at $87 million this quarter, which is up 32% over last year. Our record operating income for the first quarter was largely driven by a 27% growth in CIG segment operating income and a 13% growth in GSG segment operating income. The resulting CIG margin of 12.5% is up by 100 basis points over last year, and the GSG margin of 14.7% is up 70 basis points over last year. We also had lower corporate costs, which contributed to the better margins.
All told, on a consolidated basis, this resulted in an EBITDA margin of 13.7%, which is 170 basis points over the first quarter of last year of 12%. Our GAAP EPS came in better than our adjusted earnings per share of $1.19 and better than the top end of our guidance range of $0.98-$1.03. The difference between our GAAP EPS of $1.25 and the adjusted EPS of $1.19 was due to the benefit from employee retention credits received in the quarter related to COVID-19 programs instituted back in fiscal 2020. As you can see, our record revenue and profits have further translated to a continued increase in our cash flow generation.
Cash flows generated from operations for the first quarter totaled $82 million, which is up 148%. Our focus on working capital and cash flows has resulted in our DSO decreasing to 61 days as of the first quarter. This is a further reduction of 6 days from last year at this time. For many of those who have been following us for a while, you may remember that our long-term goal was to generate a DSO of 70 days. I think, however, we now believe that we can do better and generate a sustainable DSO below 70 days. You know, also, I don't look at the DSO just as a financial KPI.
I also look at it as an indicator of our client satisfaction, resulting in timely payments for the work that we perform on so many projects throughout the year. Our net debt amounts to about $58 million. Our net debt to EBITDA was at a leverage of 0.2x this year versus 0.5x a year ago. This reduction in net debt by $81 million dollars compared to last year.
As we presented here today, these high-quality results, including an increase in EBITDA and higher margins, along with strong cash flows, lower working capital requirements, have all resulted in a return on invested capital of 20% over the last trailing twelve months. Now, our long-term capital allocation strategy calls for a balance of investing in the growth of our business, managing the balance sheet, and also providing returns for shareholders. For the trailing twelve months, cash from operations generated $354 million or about $6.50 per share. Sequentially from last quarter, this was an increase of 16% from our fiscal 2021 record year, where we generated $304 million in cash flow. During the first quarter, we continued to provide significant returns to our shareholders through both dividends and share buybacks.
Regarding our dividend program, during the past quarter, we paid out $10.8 million in dividends. I want to announce that our board of directors approved our 31st consecutive dividend, which will be paid in the month of February at a rate of $0.20 per share, which is an 18% increase over last year. Furthermore, we utilized $50 million in the first quarter on our stock buyback program. As of the end of the first quarter, we have a total of $498 million remaining in our approved stock buyback programs. All told, for Q1, we've returned more than $60 million to our shareholders through these dividend and share buyback programs.
Our strong cash flow has allowed us to successfully complete several strategic acquisitions and continue to return capital to our shareholders while de-leveraging to 0.2x from 0.5x a year ago. The slower leverage point also helps us to de-risk the impact of inflationary interest rates on the company. Our strong balance sheet and available liquidity of over $900 million positions us to continue investing in technical capabilities and strategic growth areas, as Dan will cover next. You know, I'm very pleased to share these financial results for the start of our fiscal year. I wanna thank you for your support, and I will now hand the call back over to Dan.
Thank you, Steve, and thanks for covering the details on our quarterly performance, not just on the work from our operations, but also where we sit on the balance sheet. You presented it quite clearly. We have here at Tetra Tech three key market drivers that continue to shape our clients' spending, long-term programs, and investments in the future. The first is the U.S. government has identified climate change, water, and environmental protection as critical priorities. First and foremost, these priority programs are implemented through the federal budget associated with spending by key agencies that we work for, such as the U.S. Army Corps of Engineers, the U.S. Environmental Protection Agency, and the U.S. Agency for International Development.
A second area that is a key driver for us is the U.S. government is now also working with state and local governments to implement the Infrastructure Investment and Jobs Act, or IIJA. This supplement, additional fundings to the government budgets, especially at the state and local levels, are creating long-term increases in spending for water, environment, and resilient infrastructure services that we provide and that we're market leaders in. The White House's guidebook to IIJA was just released Monday, three days ago, and outlined an estimated $80 billion that's been identified for distribution to states as just the first step in releasing the funding associated with IIJA. The third market driver is in our international markets.
Here we are seeing a new focus on climate change programs and an increase in associated budgets, including decarbonizing buildings, biodiversity and land management, and protecting the oceans. This focus is resulting in an increased demand for our high-end consulting and engineering, our high-end consulting engineering services in the United Kingdom and Australia and all throughout Canada. I'd now like to highlight how these same priorities are affecting our commercial clients. We've previously commented on sustainability drivers across our government clients, but more recently, we've also seen our global commercial clients significantly increase their commitments to sustainability. As part of corporate reporting, companies are focused on ESG or environment, social, and governance metrics, and in particular, the E or the environment aspect. This has resulted in very public commitments to science-based targets, schedules for reduction greenhouse gas emissions, and increased funding for sustainability initiatives.
Increasingly stringent government regulations are driving additional spending for our scientists and our engineers to investigate, assess, and evaluate innovative treatment technologies to address emerging contaminants such as PFOS. At the same time, the bar is being raised for the restoration of impacted lands. It's being increased from just basic cleanup to more sustainable solutions that now often include the creation and management of biodiverse ecosystems. I would now like to present our outlook for fiscal year 2022 across our four end client sectors. First, our U.S. state and local should continue to grow at a double-digit pace for us between 10% and 15%. We expect continued strong growth in this sector as additional projects are initiated by our clients. This growth rate excludes future revenues associated with any extraordinary or episodic disaster response activities that we may undertake.
International work is expected to be about a third of our business, evenly split between government and commercial work. Our international work is expected to grow at 10%-15% rate as we increase our support for sustainable infrastructure and climate change services in the United Kingdom, Australia, and Canada. U.S. commercial work is expected to be about 20% of our business and grow at a 5%-10% rate. This growth will be supported by our clients' programs associated with sustainability, including environmental restoration, high- performance buildings work such as net-zero building designs, and renewable energy programs. Our U.S. federal work should grow at a rate of 5%-10% as budgets for fiscal year 2022 finalized in alignment with Biden's administration priorities.
We assume, however, that increases associated with the new Infrastructure Act or the IIJA funding will not begin until the very end of fiscal year 2022 and most likely in early fiscal year 2023, creating an increased tailwind as we move into the next fiscal year. Therefore, we've not included any significant contributions in revenue to our FY 2022 outlook. I'd now like to present our guidance for the second quarter and for all of fiscal year 2022. Our guidance for the second quarter is as follows. For net revenue, our guidance range is from $620 million- $670 million, with an associated earnings per share of $0.86-$0.91. Now, as noted in my opening remarks, we are increasing our full- year guidance for both revenue and for earnings.
The excellent performance we had in the first quarter has been incorporated into the full- year guidance. For revenue first, we've increased the bottom end of our guidance by our net revenue beat in the first quarter, resulting in increased guidance for net revenue of a range of $2.65 billion-$2.8 billion. For earnings per share, in the first quarter, we beat our quarterly guidance by $0.21 above the lower end and $0.16 above the high end. Based on our profitability, we now have estimated that our tax rate for the remainder of the year will increase from our previously estimated 25% to now 26%. This tax increase represents about a $0.02 per quarter increase or an increase of $0.06 over the remainder of the fiscal year.
Our guidance incorporates both our first- quarter beat and the impact of the increased tax rate for the remainder of the year. As a result, we're increasing the bottom and top end of our earnings per share guidance for fiscal year 2022 to $4.15-$4.30. Now, this guidance does include the following assumptions. It does assume, and it's incorporated into our guidance for the year, of a $10 million charge or $0.14 per share associated with intangible amortization. It does, as I've just commented, assume a 26% tax rate for Q2, Q3, and Q4 for each of the remaining quarters this year.
It does assume that we have a 54.5 million average diluted shares outstanding, and it excludes any contributions from future acquisitions that may happen, subsequent, to this call, between now and the end of the fiscal year. In summary, we had an excellent first quarter and start to fiscal year 2022, setting new first quarter records for revenue and earnings per share performance. Our high-end water environment, sustainable infrastructure, and renewable energy services are directly aligned with our clients' priorities. Our strong backlog of funded and authorized work provides us with both excellent visibility and momentum as we move throughout this year and look to even increase as we move out into the coming years. At this point, Laura, I would actually like to open up the call to questions.
The question and answer session will begin now. Please be aware that there will be a 30-second pause in our webcast to allow for buffering. At this time, audio participants are invited to submit their questions. Please remember to mute the audio function on your computer before you speak. If you're using a speakerphone, please pick up the handset before pressing any numbers. If you would like to ask a question, please press star one on your touchtone phone. Our first question comes on the line of Noelle Dilts with Stifel. You may proceed with your question.
Hi, guys. Good morning, and thanks for taking my questions.
Absolutely.
Sure. First, I was hoping that you could expand a little bit more on what you're seeing and expecting as it relates to margins. Well, really, margins in both segments were strong in the quarter, GSG particularly strong. Could you speak to how you're thinking about, you know, the strength in the quarter, how much of that is sort of sustainable versus how much maybe benefited a bit from storm work? Then if you could speak to your expectations for margins for each segment for the year, if anything's changed relative to the last conference call and also longer term. Thanks.
Absolutely. Let me start with any extraordinary contributions during the first quarter from unusual events. We did have a contribution from disaster activities that did contribute to margin expansion in the first quarter, and we typically associate that with increase in utilization. The GSG margins, which were 14.7% during the quarter. A year ago, we were 14%. We were, if you take a direct year-on-year, up 0.7%. About half of the increase in the GSG margins we've associated with increase in utilization, such as being driven by the disaster work.
The other half is actually mix shift by adding more data analytics to high-end federal IT activities. If you take a look at just the GSG margins in the quarter, about half of the 70 basis points was associated with increased utilization, largely driven by the disasters. That would be about 35 basis points, since our government work as a GSG segment is about half. If you actually impute it to the entire company, it'd be about half of 35 basis points, so about 17 basis points if you wanna be precise. It did contribute, but it's roughly on that order. I would call it contributed, but it wasn't the driver.
With respect to our CIG margins, they were just an increase in performance based on the mix shift that we've been employing as we've continued to emphasize higher end consulting and front-end engineering work, which actually does carry margins, higher margins. I'd say it's more structurally representative of where we're going. With respect to what are the annual or annualized margin rates for the two groups, I would say that we've increased this year for CIG on an annual basis, a range of 11.5%-12.5%. We moved both the bottom and top end up another 50 basis points from what we were estimating and achieved last year. On the government services side, we've increased it to 13%-14% on an annualized basis.
I will make one observation. We do have a bit of a seasonal effect with our business in the second quarter, and this most notably the weather and the downtime impacts our Commercial and International Group, and it's mostly on the I part international, primarily in Canada with the colder weather. Although I think the folks on the East Coast would say it's extended well down, I guess earlier in the week, all the way down to Florida. Of course, it's impacting much of the central U.S. We do see less activity during the winter months of January, February and March, which are our Q2. We will see margins a bit lower in Q2. That is not unusual. You've seen it every year from us.
I would expect margins to be muted in Q2 and of course, much higher in the emerging Q3 and then Q4. On an annualized basis, GSG at 13%-14% and CIG at 11.5%-12.5%. Again, I've just spoken a bit to what took place in Q1 that was a bit extraordinary. I hope that covered some of those comments.
Great Questions, Noelle.
That did. Thank you. Very helpful. Secondly, you've definitely stepped up the share repurchase in the quarter. You know, shares have been under pressure in the early part of the year. Can you kind of speak to how you're thinking about priorities for capital allocation and the relative attractiveness of repurchase versus acquisitions at this point? Thanks.
Well, that's a good question. I think Steve covered it. I'll basically just do a quick recap on the priority. Number one is, of course, we want to fund internal organic growth. That's embedded in our operations already with respect to CapEx, which is quite modest. We're down to about half of 1%, so we're incredibly asset- light. The organic growth that we are realizing the company is only requiring a very, very small amount of our cash generated from operations. Second, we're committed to the dividends. We've now in every year that we've had the dividend, as Steve had indicated, we're at 31 consecutive quarters. If you do that math, it's about 8 years.
Every one of those years, we've increased the dividend double digits, and we're committed to that and to continuing that process. That's the next priority for, besides internal growth, that's the next priority for our use of capital. The next is actually used for acquisitions and making Tetra Tech more competitive and furthering our strategic plan into the marketplace and to differentiating ourselves in the water environment, sustainable infrastructure, renewable energy markets. We are very focused on bringing the best and brightest firms to come join and be our partners here at Tetra Tech, and that's through acquisitions. Now, acquisitions can be less consistent with respect to the timing and the size, and therefore we've employed a buyback.
In fact, this was the second greatest quarter we've had and the amount of buyback we've had, and it was not triggered, even though there's been some dislocation in multiples and pricing. That wasn't unique to Tetra Tech. Of course, there was a pullback across, you know, entire market sectors. We put in essentially an even purchase throughout the quarter. Some weeks it's higher, some weeks it's lower. We also are supportive of our company at an underlying bid in the event that we would become more constructive even than what you've seen here. What we see is that the cash generated from our operations, if you take a look at this last quarter at $61 million between dividends and buybacks, we can sustain that through cash from operations.
It's not our goal to just pile up cash and leave it unreturned to our shareholders. Through dividends and buybacks, we will return the cash to our shareholders, and then we'll use our credit facilities to remain active on the M&A front. We're not borrowing cash in order to create a dividend and buyback. We're actually using the cash generated from operations. In fact, we have surplus cash to actually fund a portion of our acquisitions. If we need to go with more acquisitions or larger, as Steve said, we have access essentially to a billion-dollar credit facility to put no limit on the ability to have great companies come join us at any time. That's sort of the hierarchy in how we think about the use of our capital we're generating.
Thank you. Very helpful.
Our next question comes from the line of Sean Eastman with KeyBanc Capital Markets. You may proceed with your question.
Hi, Dan and team. I'd love to dig a little deeper into the growth optionality in commercial. I think the high- performance building side is pretty well defined, but if you could round out what other opportunities are firming in commercial and maybe tie that in with this nice margin accretive mix shift we're already seeing in the commercial book of business, that would be super helpful.
Yeah, it's a really good question. It's one we've really not spent a lot of time talking about in our investor calls quarterly here for some time. I know over the past few quarters, and certainly through the early part of the pandemic, we saw commercial impacted negatively. We've actually indicated that we thought that the first quarter of this year would be the second step in inflection to go from being flat or even down to actually growing. We actually seeing that continue. What we find to be quite encouraging is not only do we see the commercial, and that's not just in the United States, it's really for our very large multinational global clients, including heavily on the industrial side.
There's more dollars and more commitments in funding and contracts being committed by these clients that we both have here at Tetra Tech now, which is many of the Fortune 100. We're also looking to bring other firms onto Tetra Tech. If you ask what's one of our priority areas, you certainly heard me in the past, our U.S. federal data analytics, IT, differentiation with respect to using advanced data analytics to solve some of our clients' problems, water firms both in the U.K. and Australia. We are now going to add here tactically looking for firms to join us that have leadership positions with global commercial clients. These are solving their problems regarding sustainability. A big issue has been water.
We've always talked about this, both for water, for supply, for their operations, for their containment and treatment before any type of discharge, and of course, their long-term sustainability and resiliency programs. What we do like, and I have said this on every call, I'm sure, for the past many years, that the CIG or Commercial/International Group has the ability to have margins much higher than our Government Services Group. That's going to be driven by work that we do at the C-suite for our large global commercial clients, where we're bringing exceptional value. While it does carry higher margins for us, it actually carries enormous savings for our clients by selecting the right alternatives, the right compliance activities, and the right decisions to be made in their future for anticipating new regulations and compliance requirements on the environmental and water side.
We think not only carries better margins for us, which will help accelerate CIG's closing, and in fact, I would expect beating of GSG's margins. I'll tell you, the value we're bringing to our clients through these services are really extraordinary. I believe not only best in class, in many instances, really not offered by anyone else.
Interesting stuff. To the extent, if hypothetically, you know, the business cycle rolls over, I mean, how much sensitivity is there in this you know, sort of growth prospect pipeline for the commercial business?
Well, that's a real good question. I know that we've had in the past, if we went back 10 years ago, where we were actually doing much more of the detailed design and even construction management. We saw the volatility or the cyclicality of commodities drive that business up and down for us. By having moved way to the front end and actually working on the front-end planning, the strategies and the upfront prioritization of programs, we find ourselves much, much less exposed to the cyclicality that you see with commodities, that is inherent in a lot of these large multinational programs, and especially when you're talking about fossil energy companies, which are really oil and gas or mining. We're moving away from that.
In case of energy, it's not just oil and gas, but it's transformation to add other energy sources, such as renewable energy or even decarbonizing some of the standard oil and gas or fossil fuel production that exists today. We would find the work that we do to be much more consistent. I will say we're prioritizing quality over quantity. By not doing the implementation, the projects are smaller, they're less volatile, and they're higher margin, and they're highly differentiated. Because when you become the long-term consultant and partner with the strategy and implementation of where the companies are going, we see that to be much less fluctuation through these business cycles than would have been seen if you're actually implementing these solutions.
Okay. Interesting. One last quick one for me. Dan, how would you characterize the timing risk around the IIJA tailwind for Tetra Tech? I mean, are you increasingly convicted that we're gonna see, you know, you know, meaningful momentum there starting in fiscal 2023? How would you characterize that?
You know, I would say I wouldn't say that we're increasingly focused. We're very methodic about this. We're very analytic about this. I think my comments regarding the first $80 billion, which is just the first installment that's been earmarked for the programs, and in fact, the guidebook that's come out. So that's further. I would say, does that make us more encouraged? No. It's just additional support to what we've seen. I do think it's important to note, as in my comments, that we've not included any material contribution from IIJA into our fiscal 2022. We think it'll come out in the fall. We're already seeing contract vehicles be put in place. We think the first beneficiaries of the funding are going to come out to current contract holders.
Here at Tetra Tech, with over $20 billion in existing contract capacity that we have, I think we're there. I've heard, anecdotally, you know, impact to contracting officers, you know, being impacted and not being able to come to work because of the Omicron or something else. We don't need new contracts. We have contract vehicles. Actually, the technical staff and the people at the front line can provide funding through the vehicles we have now. I would say we continue to be optimistic regarding the timing of IIJA. To reiterate, just to take your question actually one step farther, some have asked, "Well, what about the Build Back Better?
Has there been some disappointment or discouragement that it hasn't passed? In fact, here at Tetra Tech, we think that a very methodical careful furthering of that on a timely basis, and in fact, as components, there's been some discussion of breaking it up into pieces, actually may be better for us. It will create the governments to have the systems to actually put the new funding through to get to the contractors and in fact, allow the best contractors to perform this work. Not everything at once, but to actually do it in a thoughtful, meaningful way that will get the best value for the government. To IIJA, we continue to be optimistic, and I wouldn't say we're more optimistic. We continue to track it, and it's coming in just as we expect at this point.
Excellent. Thanks so much for the insights.
Our next question comes from the line of Tate Sullivan with Maxim Group. You may proceed with your question.
Hi, thank you. Just to start off, can you just give more background on moving the high-performance building from GSG to CIG? I mean, what does it show in terms of the evolution of that business? I would imagine it could be in both based on the end customer, but yeah.
Yes. If you went back 3 years, 2 years, even a little more than a year ago, the largest revenues were being generated here in the United States, and a lot of it was government work. If you went back pre-5 years ago, it was 100% U.S. It was mostly East Coast, and it was about 50/50 government and commercial. It made sense to go to government. When we added a West Coast operation about 4 years ago, it was still all United States, and that was also about 50/50 government and commercial. I'd say in the U.S. there could have been a decision, but we were looking to grow government more, so that's why we put it in GSG.
About 3.5 years ago, we actually acquired our first international buildings practice, high- performance buildings practice in Australia, headquartered out of Melbourne with 1,000 engineers. Now that all of that work was being done and contracted for outside the U.S. Very quickly, the work that we had within the buildings had moved to be international, and U.S. was about half commercial. Of course, with the most recent acquisition back in August or in our fourth quarter of Hoare Lea, which is all international in the United Kingdom, the overwhelming majority of the revenue became either international, which was in the U.K., is all international. Australia is all international, and the U.S. is probably close to half commercial.
That when you're sitting at 70%-80% of the collective buildings group, residing either in commercial or international, it made sense to house it there. Now, we didn't really wanna break it up, because we're sharing clients, we're sharing projects. I assure you, one of the big growth areas that we see in our high- performance buildings area is actually with the U.S. federal government. Now we're growing work right now with the Australian government through their Department of Defense, through MoD, Ministry of Defence in the U.K. We do have government work, and we have had that overseas, but we're looking to grow that even more here in the U.S.
The reason we moved it was to keep it consolidated so the group could work cohesively, seamlessly and bring all of the best that we have in Tetra Tech to the clients and not have to go inter-segment. That's the reason we moved it fully. Now, just as a point, we didn't move the entire high- performance buildings from government services to international because half of it or more than half of it was already in the international group for the work that we had in Australia and of course, in the fourth quarter in the U.K. That was the rationale for consolidating it into the CIG segment.
Thank you for that context, Dan. You mentioned emerging contaminants in your pre-prepared remarks and in the annual report. You showed that you mentioned $50 million in new programs to investigate and treat emerging contaminants. Was that up from a base of zero the prior year? You also mentioned the new ion treatment plant. I mean, is this an ion exchange plant? Is this an opportunity right now in just a couple states? Has it already grown to multiple states? Can you go into a little more background on that opportunity, please?
Sure. We're up to $50 million in. We have $50 million worth of orders to investigate emerging contaminants. To be specific, that's primarily PFAS. Now it's not up from zero. It was up from what I would say coming into 2021. To look back a year, that number was probably around $20 million. It's up by about 150%. It's growing. Now with respect to ion exchange, there are a number of different methodologies treating PFOS. I guess the conventional best demonstrated available technology has been carbon or granular activated carbon and also ion exchange. Tetra Tech did the design here in California for the largest PFOS municipal treatment facility in the United States. We happened to have used ion exchange.
There are other methods that we are working with on innovative technologies that are looking to be to disrupt these technologies of either ion exchange or granular activated carbon. We did call it out because it's first of its kind in scale for a municipality. We do think it's going to grow. There are several things that are driving it. One are the responsible parties who've discharged PFOS, which is really an additive to firefighting foam, largely used by the military, but other firefighting institutions also. Ultimately, this is on track to be regulated as a drinking water contaminant that will have a maximum level that will be half that will be treated at every single municipality in the United States.
Similarly, they're developing drinking water standards in Australia and the United Kingdom, where they're well down the road, similar to the U.S., sort of moving in parallel to developing these. What is the market opportunity? Adding a treatment technologies to treat PFOS at every single water supply utility in the U.S. That's ultimately our eye on the prize. Ultimately, the demonstration of putting full-scale treatment in place, we're among the first to do it, and certainly the entity to do it at the largest scale in the U.S. now. That's what we're focused on. It isn't going up to 50 from zero, but it hasn't hit that steep part of the curve in funding, which will be driven by regulatory requirements. That should take it and have it grow by really orders of magnitude.
Thank you, Dan.
Thanks, Tate.
Our next question comes from the line of Marc Riddick with Sidoti. You may proceed with your question.
Good morning.
Morning, Marc.
A lot's been covered in the Q&A, which is great. I did wanna sort of just circle back on a more high- level, just you as to maybe what you're seeing out there within the acquisition pipeline today, maybe versus a year ago. I guess last calendar year, going by calendar year, you guys ended up doing five acquisitions. I wanted to sort of get your thoughts on maybe if you compared what the pipeline looks like now versus a year ago, as well as maybe the attractiveness of international versus domestic. Thank you.
Thanks for that question, Marc. I think our acquisition pipeline actually looks very consistent to what we saw a year ago. We're looking at it on fiscal years in our calendar, but we did 4 acquisitions in fiscal year 2021. We did 1 in our first quarter, so we've got 1 down. It looks relatively similar. We're relatively agnostic whether or not it's international or U.S., because some of our priorities with respect to international, particularly in Australia and the United Kingdom, with adding water consultancies is a priority. We wouldn't put that priority over adding additional federal IT companies here in the U.S. or advanced data analytic companies, primarily here in the U.S., or digital water companies here in the U.S.
Really a tactic that I think will contribute to the company very high-end commercial environmental companies here in the U.S. If you'd asked if a water company came up in the U.K. or Australia versus a data analytics company or a commercial high-end environmental company here in the U.S., will we go international or will we go U.S.? Will we go U.S. environmental over IT? My response is we'll do all four. We'll do one water in U.K., Australia, and we'll do an environmental in the U.S., and we'll do an IT company here in the U.S. I think with the balance sheet we have, that Steve covered, it's not an either/or. For us, it's just one criteria.
Will it increase Tetra Tech's competitive position, bring new clients, and differentiate us in the marketplace? Will it make us better than we are today? If the answer is yes, we don't have a governor or a threshold by which we have to make a selection of one over another. With respect to what the pipeline looks like, it looks very similar to what we saw last year.
Okay. I guess I would be remiss if I didn't ask a question which a lot of folks are concerned about across the board, and that's just overall labor availability, spending, recruiting, and the like. I was wondering if you could give us a quick update on sort of what you're seeing and what your expectations are, and maybe also tying that into, you know, given the backlog and the opportunity, growth opportunities that you see going forward. Thank you.
Yeah, it's a good question. It's probably the most common question I receive, and not just myself, but really our entire team, is, are we seeing labor shortages? We have not seen labor shortages. We've not had a shortfall of labor to perform any of the work we have here. We've had. We have had, there's been a lot of consolidation in the environmental water fields. Some of them have been consolidators that have caused disruption in those that have actually gone through this consolidation. We've actually been a big benefactor of what I would call very high-end, internally, we call them strategic hires, but I would call them thought leaders or technical leaders in the marketplace. Interestingly enough, that's actually gone quite well for us.
We do track very, very closely our turnover rate, and our voluntary turnover rate is actually down slightly once the pandemic has started from pre-pandemic levels. Now, I think some of it's kind of in the noise. We're down a few tenths of a percent on turnover. We're just sub 10%. Before we were, like, 9.8%, and we're down to 9.5%, so those types of numbers. I consider it de minimis, but we've not seen turnover in the company be a particular issue. We are cognizant of increases, salary pressures and inflation and the rest of it. We do pay at market.
I will say that most of our contracts, or I guess the great majority are either time and materials where we have annual escalation rates that take it into account or cost plus where it's passed through. We don't really see that. I will say one item that we're very focused on here in the company. We believe the productivity of the company can go up dramatically by the use of advanced data analytics and other technology that will allow each of our associates to be more productive than they are today. It doesn't mean I want you to work more hours. We want to actually have better output with the same amount of labor input.
We are working hard at trying to decouple that old adage in a professional consulting firm, where to do 10% more work, you need 10% more staff. That's not the case. We think we can actually produce much more output, much more value for our clients, do it faster, have even better outcomes from a technical standpoint with the same or even less labor. It doesn't mean we're gonna have less people because we're growing, we're still going to have more people. It's just gonna create new use of technologies and career opportunities that were never seen before. The best and brightest, if they come to Tetra Tech, they're going to be able to do more things on more projects in more geographies, solving more problems, using more technology than they ever could have even imagined.
That's how we're keeping up with these challenges in the workforce.
Much appreciated. Thank you very much.
Great. Thanks a lot, Marc.
Our next question comes from the line of Michael Dudas with Vertical Research. You may proceed with your question.
Good morning again, Steve.
Great, Michael.
Given you've reached, you know, another record backlog on a constant currency basis, how has the order flow been, maybe especially from either federal side? Do you anticipate that during 2022 you can maintain growth in the backlog, positive book-to-bills? Any issues given maybe some of the funding or some, you know, discussions out of Washington, especially with what's going on in defense and some of the focus has maybe turned elsewhere on how to change some of those awards to you guys?
Well, I actually was very encouraged with our first quarter book of business or new task orders being awarded to us. It was, you know, honestly, it exceeded our expectations a little bit with having one of the biggest revenue, well, having the biggest first quarter revenue that we've ever had. That normally puts pressure on the backlog in the first quarter, and normally it's a little bit lighter activity for new awards because you've got Thanksgiving and Christmas and New Year's, and it's just generally slowed down. We saw a really good flow of new orders. With respect to the first quarter, it was very good. Now, with respect to what we see in the outcome or in the outlook, it is interesting.
I do expect defense not to be a priority. We have three even buckets or even components of our federal work. Civilian agencies, things like the FAA, Federal Aviation Administration, U.S. EPA, NASA, NOAA, National Science Foundation, these folks, we see most of their budgets up. It is in alignment with the priorities of the administration. I think that the book of business and the outlook there looks very good. It's increased in priority. You can see, and I don't want to point to Ukraine as a work opportunity for us, but I do want to point out the administration's priority is diplomacy and development. Diplomacy and development are the priorities, not defense.
More dollars will go into diplomacy followed by development, which we wanna give, as the U.S., a hand up to those less fortunate, and that is actually good for all of us. As one of the largest U.S. aid contractors, we think that we'll benefit from that as the year goes on. I feel very good on that front. Now, defense. We feel that even with defense being, let's call it flat or not, the ultimate priority of where additional funding will go, we think we're going to be a benefactor of this.
How we think that's the case is we think dollars will move from weapons platforms or other areas that are considered offensive or areas that are very large portions of the budget, and it's gonna move toward quality of life, sustainability, cleaning up the environment from legacy operations of defense, creating new buildings that actually reduce the carbon footprint, high-performance buildings, many of the things that we do. We think the defense budget in and of itself may not be increased or be, quote, "flush with additional funds," but we think that the reprioritization of funding within the Department of Defense for activities that we perform should actually be pretty strong as we continue to move through this administration and into the future.
That's encouraging, Dan. My follow-up is maybe just to go back to the capital allocation and the M&A pipeline. Is there a target level of capacity, balancing capacity, that you would like which is optimal for you? Given what you've discussed, it sounds like cases will be more niche, smaller acquisitions, maybe several of them, as opposed to one or two ones that even though they might be out there for the current, are probably less likely. Is that how we should think about that relative to how the capital gets allocated this year and beyond?
Well, I would like to. I'll start with to a very, you know, high- level, 100,000-foot overview on our capital allocation and target levels. We really would like to get to a range of 1x-2x . I probably, if it went over two, but it was for the right action for the company, I wouldn't feel uncomfortable at all if it was the right strategy and the right move. Now, you would be right to point out, you've said this for I don't know how many years, Dan, one to two, and you haven't yet been able to get there. I don't think it's the worst fumble that we've had if we've been able to grow the company at double-digit. We've been able to acquire great companies.
We've been able to return cash to the shareholders. We've been able to increase our dividends, and we de-lever because of the strong cash flow. That's not what we're targeting, but it's not a bad place to be. I do think in the short term, at least if you looked at the horizon, and I commented earlier on the questions here, that I see the pipeline similar to what we saw last year and the year before, which does lend itself to several, if you wanna call it niche firms. I think every firm that's joined us, whether or not it's had 20 people or it's had 1,000 people, are not niche.
Now, maybe from a financial standpoint, as a percentage of the company's revenue, it can be characterized, but we think that they're incredibly accretive to the company's intellectual status in the marketplace, whether it's a smaller firm like EA or The Integration Group of Americas. I'll tell you, they are unbelievably valuable in the company. Whether it's a small Canadian company like Coanda, which is a very high-end research and development firm with an expert on fluid mechanics and other calculations, moved us to another level. Or if it's bigger, like Hoare Lea, a thousand people, added both geography and some of the best buildings. For us, every one of those has made us better, as some have made our revenues, you know, has moved the needle a little bit more than others.
If we find a larger firm that fits with Tetra Tech, and I think there are a few out there, that they would benefit every bit as much as us because what's important is it's not a one-way street. It's not to benefit Tetra Tech. We think that every associate that comes to us with the acquisition will have a better, brighter future than they now have on their own, and frankly, that Tetra Tech staff have on their own. Do I like to go bigger? Yes. It needs to be for the reason that we're going to be better. If that gets us to a leverage of two, I'll be even happier. We wanna be, at the risk of being redundant, we really wanna move to be better, not just bigger.
Sounds like the corporate development department's gonna continue to be quite busy. Thank you, Dan.
Okay. Great. Thank you very much, Michael.
This will conclude the Q&A session. I will now turn the conference back over to Dan Batrack to conclude.
Well, thank you very much, Laura, and I wanna thank every one of you for attending the call. I know you all have busy schedules, so take the time out to participate and ask these questions and to follow Tetra Tech. It's really very much appreciated. I feel really good, and our entire company feels very good about the start to the year with a good first quarter. Of course, we do know what we did in the first quarter is what we did before, and we're focused on doing as well or better as we move into the future.
I really look forward to giving you an update here on our next quarterly call on how our second quarter has performed and providing you more updates on both our outlook for the rest of the year and how things like the IIJA and other programs are progressing and as we see them moving forward into the rest of 2022 and beyond. With that, I hope you have a great rest of the week, and stay safe. Thank you.
Ladies and gentlemen, this concludes our conference for today. Thank you all for your participation. Have a great rest of your day. All parties may now disconnect.