As a regional operations company in the Pacific Northwest, Water & Wastewater Services supports dozens of MBR plants. We know what works and what doesn’t from headworks through disinfection. We also know that in order to be efficient, you need to be proactive and you need to know what to look for at an MBR plant. In this presentation we’ll tips on these two topics.
Hello, my name is Brian Walker. I work for a company called Water & Wastewater Services up there in the Pacific Northwest. We are based out of Mount Vernon, Washington, but our operations range across the entire state, as well as into Idaho and occasionally Oregon. What we are primarily is an operations service. We provide daily operations, service, and maintenance to a wide variety of water and wastewater utilities around the region, and as a company we have been doing this for 35 years. We are basically a cooperative of operators and other service personnel providing the staffing for a large number of systems. We operate over 100 water systems, and about 30 permitted wastewater systems. Our wastewater systems range from very small package plants and LOSS systems to conventional wastewater plants up to ½ MGD.
In former life, I used to be a river guide. Now that was a pretty sweet gig, but the siren call of raw sewage could not be ignored. And actually, spending all my free time literally immersing myself in all the waters of our region, I guess I had a greater interest in what was coming out of all those pipes draining into our rivers. So I’ve now been working in wastewater treatment for 21 years now (I’m almost ashamed to admit), and the last 16 of those have been with Water & Wastewater Services.
It was about 11 years ago that my boss told me to drop what I was doing one day and go sit in an a planning meeting. One of our customers was planning on abandoning their crummy old system, and building a new facility with a wastewater system called an MBR. “Great” I was thinking “SBR, RBC, FBR, FSW… Just what I need, another acronym “ (I was cynical even back then). I didn’t have any idea what to expect. But what I did not expect was a game changer. That little MBR was one of the first in our region, and it was the leading edge of a wave of technology which has since redirected the entire industry.
We operate many different types of wastewater facilities – oxidation ditches, RBCs, SBRs, Lagoons, FSWs, tertiary filtration facilities, as well as MBRs. About half of our wastewater facilities are membrane plants. We have a few Zenon units, and a PALL as well, but this list here is a list of the Ovivo MBRs for which we currently do direct service operations. One of the reasons we are able to operate so many plants is the very nature of MBRs and the ability to operate them remotely and reduce the necessary man-hours on site. I still manage to put hundreds of thousands of miles on my truck, wandering the state like some sort of sleepless wastewater hobo, but most of the facilities on this list only require us to be on site 1-3 times per week. In addition to routine staffing, we also provide startup and service calls for quite a few other Ovivo MBRs throughout the region, which has given us the tremendous opportunity to see firsthand the operation of a large number of these types of systems
And it is primarily because of this list that I am here today. As a regional service provider for dozens of MBR plants, Mark Parli asked if I could share just a few highlights and observations from our last decade of experiences and what we see as trends in the industry.
Well, one of the first and easiest observations I can make is that of the growth of the MBR market. Our friend Simon Judd, in his second edition MBR Book, estimates the annual growth of the global MBR market at 11.5-12.7%. This graph, produced by Fredrick Royan of the Global Water Market Research Team, takes it even one step further, indicating MBR market value currently growing at a blistering 22.4% compound annual growth rate. Anecdotally, this has been our personal experience in the Pacific Northwest as well. The significant majority of wastewater treatment projects we currently see in process are membrane related. 10 years ago we had one MBR customer, and no one else really knew what they were. Today, half of our wastewater customers are membrane facilities.
And the big question I get asked regarding this trend is WHY? Why this huge technological shift in an industry that has been bubbling air into sewage for the past 150 years? Well, there’s a lot of reasons. You could write a book on it. And people have. But I’ll give you my short answer. Two words: WATER QUALITY.
(here’s where I have to be careful to not jump on an environmental soapbox)
There’s about 7 billion of us and growing. And for better or for worse, we’re not stopping any time soon. Other than air, Clean water is the single most immediately important resource we have to protect. The world’s most productive aquifers are being sucked dry. Our fish runs and marine resources are imperiled. And clean, drinkable water is getting harder and harder to provide. None of this is any longer news to anyone.
In short, the water that we are treating, you and I, is shifting from being a waste product to being a resource. Whether it is being reused directly for washing or irrigation, indirectly for groundwater or instream augmentation, or simply being discharged to the bay, the water that we send TO the environment needs to be as clean as the water we remove FROM the environment. Much of this industry’s growth can be attributed to the ever-growing, in-your-face realization that we have to do better, that we can do better, and that we will do better. When William Shatner threatens to build a pipeline to steal water from the Pacific Northwest, that’s a sure sign that we need to do better
In Washinton State, the Department of Ecology continues to issue discharge permits for WWTPs based on what was achievable by older technologies. BOD and TSS limits are typically 30 and 45 mg/L. Fecal Coliform limits range from 25 to 400 CFU. We operate several older activated sludge facilities that struggle much of the year to meet these types of limits. Meanwhile, the MBRs that we operate turn in their monthly DMRs with row after row after row of ND, ND, ND. That’s very satisfying.
We operate one Ovivo facility in Northern Skagit County, The Bow Hill WRF, which discharges through a pair of permit-by-rule Class V injection wells. Direct groundwater recharge. We test for routine wastewater parameters every week, just like any other plant. But twice annually we test our effluent for the entire range of EPA primary drinking water standards (that’s about $5500 for a single round of samples). That plant was not necessarily designed to produce drinking water, but guess what? According to those test results, it does.
We operate one particular Ovivo facility in Northern Skagit County, The Bow Hill WRF, which discharges through a pair of permit-by-rule Class V injection wells. Direct groundwater recharge.
We test for routine wastewater parameters every week, (BOD, TSS, pH, coliforms, ammonia, and nitrate) just like any other plant. But twice annually we test our effluent for the entire range of EPA primary drinking water standards . That’s about $5500 for a single sampling event. TSelenium
Simazine
Styrene
Tetrachloroethylene
Thallium
Toluene
Total Coliforms
Total Trihalomethanes
Toxaphene
2,4,5-TP (Silvex)
1,2,4-Trichlorobenzene
1,1,1-Trichloroethane
1,1,2-Trichloroethane
Trichloroethylene
Turbidity
Uranium
Vinyl chloride
Viruses (enteric)
Xylenes (total)
hat plant was not necessarily designed to produce drinking water, but guess what? At least according to those test results, it does. (ND, ND, ND…)
So, onto Ovivo MBRs specifically:
Mark asked me to discuss what are 3 changes and 3 improvements that we have seen in these MBRs over the years. I can do a lot better than just 3 things, but I’ll try to keep it relatively short, and to illustrate let’s take a look at a small facility up in Snohomish County. These pictures of a somewhat dismal and neglected looking little plant are from the original Angel of the Winds facility – a small Kubota plant built to service a small casino and treat 25,000 GPD. It was unique in two respects: It was one of the first MBRs in the Pacific Northwest, and it was slammed into service on the almost unbelievable timeline of just 3 months. From contract signing to plant commissioning – 90 days.
The “Lab” in this plant consists of a handful of instruments and glassware perched on a piece of plywood set atop the transformer in the electrical room.
There is a very basic 2mm screening setup (this is actually the 3rd iteration of the original setup)
This is the first-generation interface. (notice the name in the upper right corner). Only the most basic metrics and controls are included on this HMI. And there’ only a couple other screens that really don’t show much additional.
Despite what would now be considered utter simplicity, for the first couple years of it’s life this plant was quite something to show off. And it was designed to be expandable, but it rather quickly fell victim to the overwhelming success of the facility at large.
In the face of the ever-growing casino/hotel/entertainment complex, it soon became obvious that the original MBR was just too small. 5 years into it’s life, that MBR was faced with a defacto stop-loss maintenance program whereby the owner did not want to upgrade equipment, support maintenance efforts, or even pay for repairs or parts. Luckily we had a very conscientious and resourceful operator running this plant, and for the past 5 or 6 years, despite purposeful neglect, that operator was able to keep the plant chugging along, producing high quality water (ND, ND, ND), even with the plant loaded beyond its capacity.
Meanwhile, plans were being laid…
… And this is a picture of a very happy Erik Thornburgh standing in front of his new Ovivo plant, designed by Ovivo and RH2 Engineering, sized for 74,000 GPD, featuring lots of new equipment including the new OV400 membrane modules.
There is the much improved Envirocare duplex screening system. 2mm perforated with barscreen backup.
There’s the much more refined HMI that we’ve all come to expect
With all the information we need, and more
There’s a bank of our favorite blowers
The new tank layout: Pre anoxic w/ equalization, followed by two trains of aeration basins, anoxic tanks, and Microdyne membranes.
And the view from the back porch.
Notice that there are covers on the MBR tanks but not on the others. The MBR chambers are really the only ones where it is important to keep leaves, branches and other large debris out. The plan is to place screening at the weir gates in between the post-anoxic and MBR tanks.
So to get back to the question at hand, 3 changes and 3 improvements we’ve seen over the years : (I should point out that these lists are the same. After all it wouldn’t be good to make changes that were not improvements..)
In the interest of an open and honest discussion, I was also asked to address the top 5 problems we have seen in plants:
notably absent from this list is membrane failures. It’s interesting to note that the absolute heart of these MBR systems – the membranes themselves – are not usually a source of failure. There are certainly plenty of stories of membrane failures out there, but they are usually a casualty of some other failure within the system. It is not unreasonable as an operational goal of the future , especially with the new generation of membranes, to make those membranes last the life of the system (20+ years).
Here’s a visual of a developing ragging issue. If an initial inspection shows this up top…
Having been through startup and operations of both Kubota and OV membranes, Mark also asked for a comparison between the Kubota generation of plants and the new OV membrane plants. Here’s a short list.
OV membranes are almost impervious to punctures like this. Here’s some examples of the type of damage we’ve seen with Kubota membranes. If you get things like this…
Then you get these. Bacterial escapement. 100% intact membranes (either kubota or OV) will have nearly complete bacterial retention. Often times small leaks show up in the form of coliform counts before they show up as significant turbidity.
This list is a leftover from a previous presentation in which I was asked to come up with a comprehensive list of all of the components (material, operational, and situational) that are elements of a successful MBR project. Well, the list was long, and I’m not going to go over it here today, but what I realized as I went down the list, was that almost all of these components were incorporated in one particular plant.
A few parting shots of one of the newest plants out there. In a previous presentation, I was asked to come up with a comprehensive list of all of the components (material, operational, and situational) that are elements of a successful MBR project. Well, the list was long, and I don’t have time to go over it here, but what I realized as I went down the list, was that this particular plant represented almost my entire list. This is my dream plant. This project was designed for the Nisqually Tribe by Parametrix engineering. It is still currently in the startup and commissioning process, but it promises to be one of the really good ones