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VOS6-7 Full Episode – Water Reuse

VOS6-7 Full Episode – Water Reuse


[music]>>Kanesa Seraphin: In this episode of “Voice of the Sea,” we’re learning about the newest strategies for recycling waste water. We’ll check our farms that use recycled water and tour a new University of Hawaii building that captures and treats wastewater and rainwater. But first, we start off at Manele Bay Wastewater Treatment Facility on Lana’i.>>Joy Gannon: Lana’i has the capability of recycling 100% of its wastewater on-island. We’re the only major Hawaiian island that has that capability. This plant takes all the wastewater from Manele, so all the residents, all the small boat harbor, the hotel, the golf course, et cetera. We are producing the highest quality of effluent at this treatment plant, it’s called R1, or recycled water 1, so we’re meeting the highest standard set by the Department of Health in Hawaii. We are processing about 60,000 gallons of influent every day. We’re recycling that water into what’s irrigating the golf course right now. We’re really essentially farming bacteria. Certain bacteria like aerobic processes or want to have oxygen, and certain bacteria like anaerobic processes, so they don’t want to have oxygen. There’s seven different processes that are happening through these different tanks. Sometimes we’re adding air, sometimes we’re settling, sometimes we’re decanting and moving material. But in essence, we’re making the bacteria as happy as we can make them so that that bacteria are eating away and happy. Right now you can’t smell anything. I mean, it smells almost like a rich soil. We take samples every single day, and then we also take samples every week. What’s coming into the plant, what’s leaving the plant. Behind me, the head works has essentially two different functions. So, it is removing any kind of stringy material that could possibly interfere with our pumps. And it’s also removing kind of the grits, the sand and the other things that could possibly clog up our treatment plant. From where we just were at with the sequencing batch reactors, the wastewater comes through those filters over there. They’re about eight feet wide if I remember right. And the wastewater is filtered through all that sand. That’s actually kind of a special sand, a silica sand. And by the time it’s reached that filter, it comes into this tank here. And this tank is what we call R2 water. From the R2, it is chlorinated. Once the water is chlorinated, it comes into this basin here. And this basin when you’re looking at it, it almost looks like swimming pool water. And you can almost smell almost a little bit of a chlorine smell to it. This is our testing laboratory. We also additionally send out tests to a third party lab as basically a quality control check. These samples were taken this morning up at the head works. This is the influent that’s coming in. The second sample bottle, this is taken from the sequencing batch reactor. And you kind of look at this and say, “Oh, this water is cleaner.” But this is full of our little happy bugs that are actually doing all the work for us and are eating away at the material that’s in the sample. This sample is at the end of the sequencing batch reactor process. And the final sample is after it has gone through the filters and been chlorinated. And this is a drinking water sample, so you can kind of see the clarity of an R1 water sample and then a drinking water sample.>>Kanesa: So, we’re sort of standing here at the end of the process.>>Joy: We are. This is our 3 million gallons reservoir of R1.>>Kanesa: Okay, Joy, tell me a little bit about where we are now.>>Joy: So, we’re up in Lana’i City itself. We were down in Manele, and we came up the mountain about eight miles and quite a bit in elevation. So, we are at right next to the Maui Wastewater Treatment Facility, so that is a Maui County wastewater treatment plant. And then we accept the effluent from Maui wastewater treatment plant, and then we polish it here at our facilities to R1 standards. So, down below, when we were looking at all our happy bugs and our bugs doing all the work for us, here we’re letting the plants do the work for us. We accept the wastewater from the county, and it slowly filters through all these hyacinth plants. And so, the hyacinth plants are using the nutrients in that water and growing. You can still see they look like pretty happy plants.>>Kanesa: And how is that water used in town?>>Joy: That’s used for irrigation like it was used for irrigation down below. In Manele we’re using about 50,000 gallons a day roughly. Here we’re able to produce about 350,000 gallons a day. Because of that, this treatment plant and the Manele treatment plant, between the two we have the capability of recycling 100% of the wastewater on the island.>>Kanesa: And how long has this part of the operation been going?>>Joy: Since the 1990s, so quite a while. If you think back on it, humans have been using plants to recycle for, you know, generations upon generations. So, after it’s gone through the hyacinth and made its all the way down through both hyacinth ponds, it’s pumped back into our filters, where we have sand just like what we saw down at Manele. The water filters through the sand filters, and then you can see the piping that goes through these boxes. And those are our UV disinfection boxes. And that finalizes our treatment process. And from there, we store it until it’s ready for– needed for use.>>Kanesa: And where does it get stored?>>Joy: It’s up at the reservoir, and we’re going to go there now.>>Joy: This is our 10 million gallon R1 reservoir that is used to irrigate portions of the city. This is a natural resource, 350,000 gallons of water a day is being recycled. That means 350,000 gallons a day that we don’t have to pump out of the ground, that can stay in the aquifer, that can stay in the Lana’i hale. We don’t have to do the pumping costs. We don’t have to do the chemical costs and all that that involves. So this, it’s an untapped resource. [music]>>male announcer:The University of HawaiiSea Grant College Program,focused on Hawaii’s coastsand its communitiesthrough sustainable development,safe seafood supply,sustainable coastal tourism,hazard resilience,and healthy coastal ecosystems.Hawai’i Sea Grant.>>Kanesa: Welcome back. We’re at Kunia Farms on Oahu, checking out local produce being grown with recycled water.>>Elson Gushiken: In Hawaii, it’s tough doing business, being a businessman. It’s tougher being a farmer. You know, a large farm here in Hawaii is 50 acres. I mean, a large farm on the mainland is thousands of acres. So, land is expensive, water is expensive, energy is expensive, so it’s really difficult to be– to farm economically. Here at this Kunia farming community, we were already moving towards looking at obtaining recycled water from the Schofield wastewater treatment plant. The tipping point came in 2016, when the wells here at Kunia failed, our sole source for the water for Kunia Village’s drinking water treatment plant. They are also the only source for irrigating over 2,800 acres of Kunia Water Association’s agricultural farming community. So, when those wells unexpectedly went down in 2016, it became a water crisis, an immediate water crisis.>>Kanesa: I understand the farmers had already planted their seeds.>>Elson: It was critical because we’re talking hundreds of thousands of dollars worth of valuable crop, revenue for farmers. You know, money for them to sustain their lifestyle.>>Kanesa: And food for people to eat.>>Elson: And food for people to eat, yeah. It was a great success story. So, today we have over 5,000 acres here in Kunia growing produce and food that is shared with the Hawaiian community using all recycled water.>>Kanesa: These kalo field that we’re looking at here, this is all watered, irrigated with recycled water?>>Elson: Yes, and the nice thing is that they’re using recycled water to irrigate the kalo and a variety of other crops, and they’re using it with good irrigation technology, drip irrigation. Our soils have salts in it, so you can see the white on the side. So, the dripping the water helps move the salts out away from the plant. Traditional water, if you use like sprinklers, you hope that the water will percolate and carry the salts down into the soil. This way, there’s an advantage that if you move the salts out to the inner rows, it also helps to kill the weeds. They’ve actually incorporated the drip irrigation concepts that the sugar industry and pineapple industry developed 40, 50 years ago. And that technology transfer has moved over into diversified ag.>>Kanesa: And what other types of crops are now being tested with this recycled water?>>Elson: All your leafy vegetables, your Chinese cabbage, your purple cabbage, your tomatoes, bell peppers, sweet corn, potatoes, onions, bananas, avocados. I mean, pretty much everything you can think of.>>Kanesa: Is there any crop that wouldn’t take to this recycled water? Is there any reason you couldn’t use it?>>Elson: No. The Department of Health allows what we call R1 water, which is the best treated and recycled water, to be used for all forms of irrigation. In agriculture, it can be used for any root crops, whether it’s the daikon or the carrots or potatoes, as well as your leafy crops, like I said, like your lettuces and cabbages and things of that nature, and as well as the orchard crops. There are no restrictions.>>Kanesa: Our default mode has been to kind of take our wastewater and treat it and then discard it into the ocean.>>Elson: Yes, it’s a very wasteful process. We spend all this money on wastewater treatment plants, and especially in Hawaii, it goes into an ocean outflow. We’ve been forced to take an alternative approach to this. The city and county of Honolulu by consent decree with the EPA has been mandated to make improvements to the Honolulu wastewater treatment plant so that we can release less of a poor quality water into the ocean, and also look at using more of that water for beneficial reuse.>>Kanesa: And so, what are the benefits of that, of reusing our water?>>Elson: One of the challenges we have with a growing population and as we continue to pave over our lands, there’s less land that’s exposed to take in the rainfall and recharge our aquifers. We see much more runoff into the oceans. There is a certain sustainable yield. So, with drinking water, if you exceed what can be restored and replenished into aquifers, the aquifer shrinks, and you actually have seawater intrusion, and introduces salt into our drinking water resources. If we don’t address some of these issues now, we’re going to be in a lot of hurt by the time we really need it. I don’t believe that we’re going to be allowed to discharge into the ocean forever. That’s a wasted resource, and there are so many opportunities even here on Oahu to use non-potable water for irrigation. There are the agricultural communities in Waimanalo, in Waianae, on the north shore. There are golf courses that today still use potable water for irrigation like the Ala Wai golf course, the Hawaii Kai golf course, and several others. And there’s our city parks. There’s like the Central Oahu District Park up here. There’s the Kapiolani Park. There’s Aliomanu Beach Park. There’s Kakaako Waterfront Park. We have the technologies to actually scalp wastewater from the sewer line and treat it in a small satellite treatment station for beneficial reuse close by. You don’t make money on being a purveyor of recycled water. It is being a good steward and taking care of your land and water issues. The challenge here in Hawaii is that most of our wastewater treatment plants are located along the seashore. Very few are located in the center, except like the Wahiawa wastewater treatment plant or Schofield. The transmission costs to send recycled water to an end user can be really expensive. When people are looking for a dollar return on investment for water reuse, you’re not going to find it. But if you’re looking at a return on investment because of the social issues, then yes, then we have an obligation to do that. [music]>>announcer: We’re lookingfor a few heroes, mentors,trailblazers, innovators.A passion to change lives,spark curiosity, open hearts,and awaken minds.Help students answerthe question: Who am I?This could be your calling,but this is no job,it’s the journey of a lifetime.Be a hero, be a teacher.>>Kanesa: Welcome back. We’re at the new UH West Oahu admin and allied health building, checking out the design and technology that allows the recycling of water used inside the building, as well as the capture of rainwater from outside.>>Lauren Roth Venu: So, this is the new administration allied health building that was just recently constructed and finished just a couple months ago. Roth Ecological was the prime designer on all the water systems for the project. We did what we call strategic water planning, and what that really means is looking at for opportunities where they could capture, store, filter, and reuse their own water on-site, so then they don’t have to use as much of the Board of Water supplies, but it also really means that they’re mitigating pollution from not leaving their site. So, instead of just sending it down the storm drain or into the wastewater pipes, we’re actually managing it here on-site. Water reuse is basically you’re capturing where you already have used water. So, these could be things like condensate from the air conditioning, for example, here in this building. It’s very clean water to be reused, so it doesn’t require actually that much filtration. Another example is the greywater that’s from the bathroom area, so that would include like bathroom sinks, if this facility had showers, that kind of a thing. And then that water does require some filtering before it gets reused. And the last kind is blackwater, and that’s the stuff that comes out of your toilets and all that stuff, but that can actually be filtered on-site as well and turned into recycled water and be a great resource for both irrigation, and hopefully soon we can begin to use these water resources back inside for things like flushing toilets and things like that.>>Kanesa: How novel is the technology that’s being used in this building?>>Lauren: This is probably one of the first buildings to demonstrate kind of all three of these principles in one setting. Rain catchment is not necessarily a novel technology, we see that in many of the rural areas across the islands. The greywater system is pretty new for Hawaii but has been applied to multiple areas across the United States and beyond. And condensate recovery is one of those up and coming because it’s really a very clean water resource that doesn’t require that much filtration and then that much cost to actually capture and then put back into the landscape. All right, well, we’re in the mechanical room, where some of the magic happens. Over here is it’s an air conditioning system. The pipes and the system sweats. That becomes condensate. Condensate here is then collected, and that goes directly into the storage tank.>>Kanesa: So, this system, it reuses water, but it uses more electricity.>>Lauren: The pumps are not on continuously. There’s timers for when the landscape requires irrigation. And then at that point, the pump will kick on. It’s really a low energy system because we’re not talking about big pumps here. You know, I believe it’s a half horsepower pump that turns on every once in a while. You’ll see a similar configuration back here. This one is for the greywater system, so that includes the bathroom sinks and the condensate. So, here we are on the backside of the building. So, this is where a lot of the storage tanks are located. And this is the greywater treatment system that is filtering the greywater from the bathroom sinks. As you can see, it’s a little bit more mechanically complicated than what would normally just be a classic filter. And it’s designed like this so we can really make sure that we have safe water going out to our irrigation field. Essentially, the water’s going to be coming in here and then going through these fabric filters. There’s going to be a little bit of aeration that kicks in as well. That water will then go back inside the building, the mechanical room we were just in, and go through that pressurized system. And then there’s one more filter that protects the irrigation supply. Rainwater, though, is a little bit different. So, rainwater hasn’t been used yet, right? So, we’re capturing that from the roof of this building, for example, or running off the parking lot. And we’re filtering it through some of these landscapes that are actually green infrastructure called bioretention. And so, some of that stormwater will actually be filtered and put back into the ground. That meets the recharge component of the freshwater initiative. And then we have a 2,000 gallon rainwater harvesting tank that’s able to capture that water and re– well, not necessarily re-, but use that water for irrigation as well. This part of the island gets about 23 inches of rain annually. It’s probably about moderate, that’s about what downtown Honolulu gets as well. But if you look at the size of this roof, this roof is over 18,000 square feet, so it doesn’t take that much rain to actually capture a lot of water. So, what we’re looking at here is a 2,000 gallon cistern that’s buried in the ground. We expect from the amount of rain that we get here in west Oahu that this system will be able to capture about 30,000 gallons of rainwater annually, and we’ll be able to reuse that and offset that from our potable supply. There’s two strategies with rainwater. One is to have the cistern to be able to reuse that water. The other real primary strategy is to make sure you capture that stormwater as close to where it’s being generated, and get it into an engineered landscape such as the bioretention, so it’s actually a flood mitigation strategy as well as a pollution mitigation strategy. Future master planned communities really need to be thinking about these types of strategies, because we’re going to potentially have dwindling supplies of our potable water, but we’ll have all this other abundance of water around us if we just get efficient and smart about its management. We all are part of the solution, and if we want to stop having issues with flooding, with you know, our beaches without having all of the pollution that doesn’t allow us to enjoy them to go swim and surf or whatever we like to do down there, if we can all kind of do our own little bit by capturing it on-site through, you know, there’s multiple strategies to do that, then we can start making a better place for all of us.>>Kanesa: Next, we’re at the Pacific Water Conference, where we catch up with water reuse expert Dr. Bahman Sheikh.>>Bahman Sheikh: I think the biggest opportunity right now is in agriculture. There’s a tremendous amount of land that’s left fallow after sugarcane and pineapple growing left the island. And that land can be put into production of various fruits and vegetables that are needed that are now imported. And that requires water. So, what better water to use than recycled water for that purpose? Another very good potential is to treat the water to a higher level and then inject it into the groundwater reservoirs. Groundwater reservoirs are our biggest water supply source. In Oahu, it’s 90% of our water comes from groundwater, from wells. Statewide, 60%, so it’s the majority. And it’s a good thing to replenish, because if we don’t replenish it, we overdraft the groundwater. And then seawater comes in and really ruins the quality of the water.>>Kanesa: Right, which will happen more and more as we face rising sea levels.>>Bahman: Exactly. Rising sea levels, climate change are going to work against us. We’ve already seen some of this take place since the 1980s. The amount of rainfall has declined, and it’s going to get worse in the future. Right now water is priced so cheaply that it’s viewed as valueless. Whereas water is life. I mean, its value is infinite. Without water, we would be nothing, we would perish. We have so much of it and so plentiful, every time we open the tap it’s there, that we take it for granted. Over the next 15, 20, 30 years, we’re going to have a deficit. The state as a whole is going to experience a deficit of the order of magnitude about 100 million gallons per day. It’s about 10%, 12% of the overall water supply that we have. This deficit is mostly because of population increase and its demand, but the other part of it has to do with uncertainties caused by climate change and droughts and natural events that could happen. So, you add these together, these uncertainties and population growth, and they have come up with this number, 100 million gallons per day.>>Kanesa: I was looking at some of your work, and I noticed that you’d written about the ick factor, or people’s hesitancy to utilize reused water.>>Bahman: We are disgusted with our own waste. And knowing that recycled water, reused water as you called it, comes from that source, that’s the raw material for it turns some people off, especially if they’re not used to the idea, especially if they don’t know the treatment that goes into changing that wastewater into usable water. Nature does it for us all the time. There’s no new water. All water gets recycled by nature anyway. So, what we do in water recycling plants is emulate nature’s processes of sedimentation, biological treatment, filtration, and then we add oxidation with chlorine or ozone to disinfect, get rid of microbial contaminants. And if you want to go even further, you can throw reverse osmosis at it and take all the salts out even. So, we got technology, we got technology to produce any level of water quality that we need for any purpose. But unfortunately, this psychological barrier is there for people who are not familiar with the concept. But after they become familiar with it, almost 100% of people get rid of the ick factor and become advocates.>>Kanesa: Recycling and reusing fresh water will not only help protect our water supply for future generations, but also help to protect the environment by keeping fresh water in local streams and underground aquifers, and preventing excess nutrients and pollutants from going into the ocean and onto our reefs. Mahalo for watching “Voice of the Sea.”

2 comments on “VOS6-7 Full Episode – Water Reuse

  1. Water hyacinth grows at an insane rate when well fertilized so the question I have is: What do they do with the excess biomass generated by the plants?

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