Pretty buoyant at the moment. So, other than the obligatory corporate slide, I want to keep this presentation focused on just four key things. Number one, we have grown to 1.8 million ounces in resources over three emerging hubs, and that is in the heart of the WA Goldfields. We are drilling today. We do plan to continue drilling, and we plan on continuing to grow. Number two, when we do drill, we add ounces to our resource table pretty cheaply. So, the new ounces that we've added have come in at a cost of $19 per ounce in exploration costs. Three, in June, we did release the pre-feasibility study. At a $5,500 gold price, which is about where it is today, it's demonstrating a $2.3 billion net present value at an 8% discount rate. It's got an eight-month payback, and it's got an internal rate of return of 160%.
We also produced a 1.1 million ounce reserve as part of that PFS. And finally, number four, we are obviously working on the DFS. It's due in the June quarter of next year, and we want to move straight into construction and start pouring gold by December 2027. So, corporately, as a reminder, corporately, we are in a pretty strong position. We've got AUD 90 million cash as of the end of the June quarter. We've also got some options expiring end of October, and that's got the opportunity to bring in AUD 6 million. So, they're 14 cent oppies. If any of you guys own them, better start getting in the paperwork. Last year at this conference, we were trading at about 10 cents. We're close to double that today. Again, last year in this conference, we had 8% institutional ownership. We're up over 26% institutional today.
Another important point is the last 7% growth in institutional ownership, that's actually happened on market. Even the instos aren't waiting for a capital raise to get on board. Corporately, strong position. The macro environment for gold is giving us some amazing tailwinds, and we are laying some really solid foundations to build what will be a multi-decade gold business. Just from a geography perspective, Mandila and Spargoville, 70 km south of Kalgoorlie, our third project, Feysville, is only 14 kilometers south of Kal. It is the heart of the WA Goldfields. The PFS, again, demonstrated this potential multi-decade mine, 95,000 ounces per annum for the first 12 years. The financials were strong at a $42.50 Aussie gold price. They are absolutely flying where we stand today with spot pricing. Last year, I would have spoken to you about the importance of location.
With what is happening around the globe, you want to understand the jurisdiction that you're investing in, and certainly Western Australia is a pretty safe bet. Mandila, we are located on reclaimed pastoral land that now vests in the Crown. We can't water any sheep or cattle with that water, nor can we irrigate crops, and we are not competing with anyone else from a land use perspective. The area is well regulated, and it's low sovereign jurisdictional risk. So, while it doesn't eliminate permitting risk, I can certainly say with 100% belief that our risks are minimal compared to our peers. Process plant, mine offices, workshops, heavy vehicle go bay. It's all located 500 meters off that Coolgardie-Esperance Highway. That is the freight corridor between the Eastern States of Australia and Perth. Within that corridor, we've got potable water, we've got piped gas.
We're located 25 km from Kambalda, which has got fantastic facilities, a +300-man accommodation village, and an all-weather airstrip. And also importantly, every mining and maintenance contractor that you might want to use are located in Kalgoorlie, which is only an hour's drive from site. So, location does matter, and our risk profile as a result of that location is lower, which will help from a construction perspective and from an operating cost perspective. So, here's the PFS that we published in June of this year: 95,000 ounces per annum, 12 years, 1.1 grams per tonne. And then for the next six and a half years, we're actually treating low-grade stockpiles that we've built over that period, and that's producing 42,000 ounces per annum. So, a 13.2-year mine life, and then we're processing for 18 and a half years. So, this is building towards a multi-decade operation.
All-in sustaining costs, AUD 2,100, so lots of headroom there. Peak negative cash flow, AUD 230 million, AUD 180 million for the process plant, which includes obviously the plant, non-process infrastructure, tailings storage facility, and contingency. So, that's 180, and then another AUD 47 million in pre-production mining to get that all ready in front of the process plant. Simple, large-scale open pit, five and a half to one strip ratio. Financials, incredibly robust at a AUD 42.50 gold price, AUD 1.4 billion net present value, again using an 8% discount rate, AUD 2.8 billion in free cash flow, one-year payback, 100% internal rate of return. As I said before, if you're using the spot price today, that NPV jumps by AUD 1 billion to AUD 2.3 billion, and the free cash flow jumps to AUD 4.2 billion.
So, when you're pitching these sorts of stories as an MD, you're always told to avoid talking about any of the negatives. Don't touch on the risks. But the reality is project development is risky, and you shouldn't discount that risk, because once you turn on those expenditure taps, if you don't actually get your revenue on time, nor get it to the quantum you're expecting, then you can be in a world of hurt. Failure isn't going to be an option for us at Astral. So, if we see a problem, we will cut a plan to fix it. If we see a risk, we will put in place actions to mitigate. And one of our risks early on was we did have a lack of tenure to develop Mandila in the optimal way.
So, earlier this year, we completed an off-market takeover for Maximus Resources, and that has addressed that risk for us. The transaction has allowed us to ensure we minimize the distance that we haul our waste. So, that will reduce our operating costs. You can see that design on the right of screen, that all of our waste dump is neatly wrapped around the open pit. It makes for a much lower-cost operation. As part of that transaction, we've got 139,000 ounces of pit-constrained resource and 144 sq km of tenure, which we are just recently finished drilling on. So, this slide here just shows some of the recent results that we had. So, we drilled 8,500 North. We drilled a number of other targets. It was a 12,000-Meter program.
I've only put out results on the first 30% of that program, but 11 meters at 1.2, another 26 meters at 2, that's all in the one hole, 20 meters at 1.4, another 30 meters, 13 meters at 1.2, and then two holes at 1.4 grams per tonne. The thing about that, there was a paleochannel deposit near surface, and now we're already pointing to a fresh rock resource. It's early in our exploration effort, but we are confident of our ability to build a fresh rock mineral resource at 8,500 North. As I said, I've still got another 8,000 meters of results to pull out of that program. This next slide is about resource growth. In April, we updated the Mandila Mineral Resource Assessment. Then in May, when we completed the transaction for Maximus, we restated our group resources, and it grew to 1.8 million ounces.
Again, that organic growth, $19 per ounce. Importantly, when we released the Pre-feasibility, we demonstrated that we were able to convert 95% of the Mandila resources and 86% of the Feysville resources into our production target. So, that conversion rate from resource to production target, Quasi-reserve, is incredibly high. So, what I want you to take away from this slide is when we put out results like the slide I just put up, you need to have faith that as we convert that into an Astral resource, that Astral resource will convert into a very profitable mining ounce that we can truck into our Mandila process plant. So, I'll just touch on Mandila, which is the flagship deposit, for a couple of slides. Big deposit hosted within a granite intrusion, regional structure the Karramindie Shear. Where you get a deflection in that Shear is where the resources have lobbed.
Thea, Hestia, Eos, and Iris, four deposits there. With the recent transaction, we've got the Wattle Dam Gold Mine immediately to our east. That was the highest-grade gold mine in Australia from 2010 to 2013. And then 22 kilometers, sorry, that's immediately to our west, 22 kilometers to the east, you've got the St Ives Gold Camp, which is 22 million ounces now. So, this region is prolific for gold, and in our mind, it's actually inconceivable that we are not going to continue to find ounces over time on this tenure. Here is Thea in long section. We updated those resources, as I said, in May of this year, but prior to that, we drilled four diamond holes. We hit these very high-grade structures within Thea. Those high-grade structures are probably likely that they introduced the mineralization into the granite intrusion.
Two and a half meters at 170 grams per tonne, 10 meters at 28 grams per tonne, 25 meters at 4 grams per tonne. We are currently doing a 10,000-meter program of infill at Thea, and then once that's complete, we've got a 3,000-meter diamond program where we're going to test those high-grade structures, both internal within the existing Thea deposit and also extensionally. With this 99-hole infill program, we put out the first results, so the first 17 holes on Wednesday of last week. So, this program is only just beginning. We are drilling this on a 12 by 12-meter panel now to build confidence as we move towards production. And these early results are certainly indicating that the resource is living up to the model interpretations, and if anything, we've potentially got a little bit of upside to this resource.
Of those first 17 holes, 32 meters at 11 grams per tonne, 2 meters at 96 grams per tonne, one meter at 20, another 34 meters at 1.6, 9 meters at 5.1, 17 meters at 2.2, another 16 meters at 2.3. Some very solid results within this infill program. Now, finally on Thea, and I've said this countless times before, this is a 1.2-million-ounce single open pit development in a region where finding these plus-1-million-ounce is becoming exceedingly difficult to do. There is no single asset developer in our region that has the scale of opportunity that we have in front of us. Also, this deposit is the third largest in the region behind the Super Pit of Northern Star and their Red Hill deposit. This is a very rare beast. I'll just touch on exploration at Feysville for one slide.
Feysville and Spargoville, these two deposits are all about us finding high-grade gold that we can displace some of the lower-grade feed from Mandila early in the mine life to help drive the net present value, just really increase the value of this project. So, this Feysville tenement package, 200,000 ounces at 1.2 grams per tonne. Last year in this room, I said we wanted to demonstrate that we could produce 100,000 ounces of gold from this tenement package in the pre-feas. We actually ended up demonstrating 132,000 ounces of gold. The cash flow that this thing generates is very, very meaningful, and it certainly demonstrates the value you get from generating these satellite deposits and feeding them into a large-scale Mandila process plant.
With the RC drilling we are currently doing at Mandila, when that finishes, we've got a 7,000-meter program here at Feysville where we're going to target Kamperman and some of the regional projects. So, looking ahead, we've just finished 20,000 meters of drilling across Feysville, Iris, Hestia, and Spargoville, 10,000-meter program happening at Thea, another 3,000 meters at diamond to commence in October, and then a 7,000-meter program at Feysville. So, our commitment to growth, you can see that commitment demonstrated just by the amount of meters that we're putting into the ground. We've appointed the DFS engineer. We'll be announcing that shortly. We're just finalizing the actual contractual documentation with them. We're on track to announce a debt advisor. We've got some senior appointments that we're about to make, and all of this is working towards completing this DFS and moving into a final investment decision.
Environmental submissions, we expect to put in the Works Approval in the December quarter, and we need to do one more spring survey, which is about to start now for the Spargoville tenure. Native Title Agreement for Feysville, we expect to get signatures on that in the coming quarter. And this and our schedule here in terms of completing the DFS, June quarter, and then gold production 18 months after that, this is an aggressive schedule. Now, to finish off, I'll just reiterate, we are well funded. The PFS, we delivered on time and within guidance. We will deliver the DFS by the June quarter of 2026, and we are funded to achieve that outcome. We will continue to drill. We will continue to grow. As a team, we actually know what we need to do to progress this towards being fully permitted and fully funded.
We've successfully achieved that outcome before. Our projects, they're in the Kalgoorlie Goldfields. This is an infrastructure-rich region. It's got strong community and local government support. It's got a regulatory framework that we understand and we are comfortable trying to navigate. The project has conventional mining and very conventional processing. The PFS demonstrated that it produced AUD 2.8 billion in free cash out of AUD 42.50 Aussie gold price, and that jumps to AUD 4.2 billion at today's price. So, the PFS are certainly worth moving through into production. And this development timetable that we have, while it's aggressive, it's achievable, and it sees us at first gold in the December quarter of 2027. Thank you.