It is a pleasure to be presenting here and talking about the Astral Resources story to predominantly an Australian audience. To think I actually put all of this into US dollars just for this presentation. So we are a gold-focused exploration and development company. We are headquartered in Perth, Western Australia, and we are listed on the ASX with the ticker AAR. I only want to focus on four key things outside of the obvious corporate slide. So number one, we have grown to 1.8 million ounces in resources. We have three emerging hubs. We are drilling today. We plan to keep on drilling, and we plan to keep on growing. Number two, when we do drill, we add new ounces to our resource table pretty cheaply.
So our new ounces that we have added over the period so far are averaging less than $13 per ounce in discovery cost. Three, in June, we released the pre-feasibility study. In US dollar terms, it demonstrated a $900 million NPV at an 8% discount rate using a $2,750 gold price. It's got a one-year payback, 100% internal rate of return, and there's 1.1 million ounces of reserve as part of this pre-feas. And finally, number four, we are now focused on delivering the definitive feasibility study. That will be June of next year, and we want to commence construction in the September quarter of next year, which is only 12 months from where we stand today. Corporately, this is a well-funded business, $12 million at the end of the quarter.
We've also got the opportunity to bring in an additional $ 4 million from $ 0.14 OPIs that are currently in the money, and they expire in the last week of October. Last year, we were trading around $ 0.075. We're well over double that today. Again, last year, our institutional ownership was probably sitting at 8%. It's probably approaching 27% today. So at a corporate level, the right things are happening. The macro environment for gold is providing a very strong tailwind, and we are laying the foundations to build a very successful multi-decade gold business. So again, for those in the audience who do not understand the land package, this map will help orientate everybody. 44 mi south of Kalgoorlie, notice how I've made these changes, is our flagship Mandilla project and then the adjacent Spargoville tenure right alongside. We acquired that earlier this year.
Our third project, Feysville, is only nine miles south of Kalgoorlie. This is the heart of the Kalgoorlie Goldfields. The pre-feasibility demonstrated a multi-decade mine development, 95,000 ounces per annum for the first 12 years, and it certainly had a very strong set of financials. I've always been a firm believer in the concept that location matters. If you're buying real estate, location obviously matters, and quite frankly, it matters when you're trying to develop or operate a gold mine. Mandilla is located on reclaimed pastoral land that is now vested with the Crown, so with the State Government of Western Australia. The water table here is seven times saltier than seawater, and we do not have any competing beneficial land use. It is located in a well-regulated, low sovereign risk jurisdiction. While that doesn't remove the permitting risk, it certainly goes a long way towards mitigating it.
Our process plant, mine offices, workshop, heavy vehicle garage bay are all located less than 500 meters off the Coolgardie-Esperance Highway. That's a freight corridor. It connects Western Australia to the eastern states of Australia. And again, within that highway corridor, you've got piped potable water and you've got piped natural gas. Also, we're located 25 kilometers from the regional town of Kambalda. Fantastic facilities, a 320-person accommodation village sitting there just waiting for us and its own all-weather airstrip. And bear in mind, we're one hour's drive from Kalgoorlie, and every significant mining and maintenance contractor that you would want to work with has quarters in the city of Kalgoorlie-Boulder. So location does matter, and our location will lower our risk, and we are well positioned from an infrastructure perspective, which will help lower the cost from a construction and operating viewpoint.
Here's the high-level summary of the pre-feasibility. As I said, 95,000 ounces per annum over 12 years, 1.1 grams per tonne. Then we mine low-grade stockpiles for a further six and a half years, producing about 40,000 ounces per annum. The mine life is 13.2 years. The life of mine for processing is 18- and- a- half. Again, we're looking to build a multi-decade gold business. All-in sustaining costs $1,350 an ounce. The peak negative cash flow is $150 million, $120 million for the process plant, non-process infrastructure, tailings dam and contingency, and then another $30 million for pre-production mining. It's a simple, large-scale open pit, five and a half to one strip ratio with incredibly strong financials. At a $2,750 gold price, $900 million in net present value, $1.8 billion in free cash flow, one-year payback, 100% internal rate of return.
Look, our primary focus now is to successfully develop this project. From our perspective, it means you have to de-risk it. If you see a problem, you cut a plan to fix it. If you see a risk, you put in place actions to mitigate. So one of our risks was we did have a lack of available tenure to build Mandilla in what is a cost-effective way to make it also cheap to run. So early this year, we completed an off-market takeover for Maximus Resources. That has addressed that risk. The way I look at it, open pit mining is about moving the least amount of waste you can, and when you are moving that waste, you want to haul it the shortest distance possible. That image on the right is what's going to go into our Works Approval document.
You can see we've now wrapped our waste dump nicely around the Theia open pit. Prior to the Maximus transaction, it was a very long, skinny waste dump, which is awfully expensive to build. As a bonus, after this transaction, we got 139,000 ounces of pit-constrained resources and 144 sq km of tenure to explore on. We've just recently completed our first program. It's about 11,700 meters. We still have assays pending for 53 holes of this program, but the early results have indicated that there's certainly some fresh rock gold opportunities for us to pursue, so 8,500 north, which is the one that's on this section here, 11 meters at 1.2, 26 meters at 2 from the same hole. That's the one that's on that section. Further along the section, 20 meters at 1.4, another 13 meters at 1.2, and then two holes at 10 meters at 1.4 each.
So that is a fresh rock opportunity that sits beneath an existing paleochannel resource. This next slide is about resource growth. In April this year, we updated our mineral resource estimate for Mandilla, and then by early May, we'd completed the Maximus transaction. So we restated our group mineral resources to 1.8 million ounces. Again, organic growth, $13 per ounce is what it's been costing us. With the release of the pre-feasibility, we've demonstrated that 95% of our resources at Mandilla and 86% of our resources at Feysville actually converted into our production target. So the conversion rate from resource into a production target and again into reserve is incredibly high here.
So the takeaway that I want you to take from this slide is that as we deliver assay results, not unlike what we've just shown on the 8,500 north, and then as we turn those results into resources, as a potential investor, you should be confident that if it stacks up as an Astral Resources ounce, it almost certainly will turn into a profitable ounce that we will plan on mining. Now, I'll just focus on Mandilla for a couple of slides. Mandilla is hosted within a large granite intrusion located near a regional shear called the Karramindie. There's four deposits: Theia, Hestia, Eos, and Iris. Wattle Dam is basically two kilometers to the west on that Spargoville tenure that we've just acquired. Wattle Dam was the highest-grade gold mine in Australia for three years from 2010 to 2013.
Then 22 kilometers to our east, you have the 20-million-ounce St Ives Gold Camp. The point I want to make here, this region is prolific for gold. In our mind, it's inconceivable to think that these tenements won't continue to deliver more ounces over time. Here's a longitudinal projection for Mandilla. We put this out with the mineral resource estimate in April of this year. There's four. We drilled four diamond holes. The program hit some very high-grade zones potentially associated with these shears, which we believe have introduced the mineralization into the granite. 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're currently drilling a 10,000-meter infill program to a 12 by 12 density just to confirm the mineral resource estimate as we move towards mining. That program is 25% complete.
We also have 3,000 meters of diamond planned to test some of these high-grade structures within and extensional to Theia, and we plan to commence that in October. So with that 10,000-meter program that's underway, we got assay results for the first 17 holes. Interestingly, at the moment, turnaround time is about seven days in Kalgoorlie for Photon, so we're getting our assay results pretty quickly. This is early stage, but to date, the results are certainly supporting our interpretations for the resource model. And if anything, potentially there's a little bit of a bias to the upside. 32 meters at 11, two meters at 96, 34 meters at 1.6. Earlier in that hole was a meter at 20, nine meters at 5.1, 40 meters at 1.1, 17 at 2.2, and 16 meters at 2.3.
Now, with Theia, it's also important to remember that this remains the only plus one million ounce deposit within 100 km of us that still belongs to a junior, and it is the third largest deposit in our region behind the Super Pit and also the Red Hill deposit, both of which are Northern Star projects. So just a quick slide on Feysville. Feysville, just like Spargoville, for us is about finding high-grade gold that we can then use to display some of the lower-grade feed from Mandilla in the early part of the project life because that will continue to drive the net present value of the project. For Feysville, we were keen on demonstrating that we could contribute 100,000 ounces from that Feysville tenure package into the pre-feasibility. It actually contributed 132,000 ounces at 1.1.
This produces meaningful cash flow, and it certainly highlights the value of these satellite projects feeding into a large central process plant at Mandilla. When that 10,000-meter program at Mandilla finishes, that RC rig will mobilise to Feysville. We'll continue to drill Kamperman, and we've got some regional targets, so a 7,000-meter program there. So just in terms of the forward work plan, we've done 20,000 meters of RC across regional Feysville, Iris, Hestia, and Spargoville. That 10,000-meter program is underway at Theia, the 3,000 meters of diamond, and then that further 7,000 meters of RC for Feysville. So our commitment to growth is plain to see when you just look at the meters we're putting into the ground. As we move into the project development, the appointment of the DFS engineering partner is on track for later this month, so we've notified our preferred.
We're now actually just working on a contract for execution. First submissions for our permitting are planned later in this December quarter, post-completion of the final round of spring surveys on the new tenure we just acquired at Spargoville. Native Title agreement with the Marlinyu Ghoorlie at Feysville we expect to execute later this month, which will allow those mining tenements to go to grant. And this schedule from a DFS through to gold production, it is aggressive. It has us completing the DFS in the June quarter, breaking ground in the September quarter, and pouring gold by the December quarter of 2027, so 18 months after that. So to finish off, reasonably well funded. The pre-feas was 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, and we will continue to grow. Derisking the mine development, the reality is it's actually pretty boring work, but it's essential, and it's something that we are focused on at the moment. Our projects are in the Kalgoorlie goldfields region of WA. It's infrastructure-rich, strong community, and local government support. It's a regulatory framework that we are comfortable to work within. This is conventional mining, conventional processing. It is very, very simple. Nothing difficult about it. The pre-feas shows that Mandilla prints a lot of cash, $ 1.8 billion at a $2,750 US gold price, $ 2.5 billion at $3,250. Obviously, the gold price is $3,600 today. As I said just previously, the development timetable is very aggressive, and it sees us in first gold in the December quarter of 2027. Thank you.
Okay, we have a couple of minutes for questions. Just wait for the mic if you have one.
Surely. Dorothy Dixer for this massive room.
What's sort of cost to your budget for drilling all in?
Look, to be honest, I don't like setting expenditure budgets. So the intention is my team put forward compelling drill proposals, and my job is to make sure there's enough money to fund it. So that's the way I'll answer that question. Our intention is to always be drilling, though. So we'll always have an RC rig going. And as we require, then we'll bring the diamond in as well.
I'll ask one. Do you want to expand on maybe the team you've put together in terms of building out the project and development?
Look, we're certainly going to put out an update probably during October. That'll be post us appointing the DFS engineering partner, the debt advisor, and then also COO/project director and a general manager. So those roles are in, and we'll sort of announce them to the market in early October. Brilliant. Thank you. Thanks very much. Thanks Emma.