What is a pollution containment valve? (Transcription)
Hello, my name’s David Cole and I’m Technical Director at Sandfield Penstock Solutions. Today I’m going to talk to you about pollution containment valves.
What is a pollution containment valve?
What we’re talking about today is a pollution containment valve, a valve specifically designed to stop the flow, the drain’s pathway flow, so that it doesn’t carry out into the receptor, the environment.
Why would you implement a pollution containment valve?
So, if you’re looking at pollution containment valves, you probably have a firewater or a pollution risk that could leave your site and cause a pollution event. So, that’s where a pollution containment valve comes in. A pollution containment valve, it does exactly what it says: it stops the flow dead and allows the contaminated materials to build up behind the valve.
What is the difference between penstock valves and a pollution containment valve?
So, what I find is, is that often engineers specify the dreaded phrase, Penstock Valve. This is a very generic term and probably ten years ago was used a lot in guidance notes, you could see it everywhere – if you read the latest guidance, CIRIA 736 now, it doesn’t mention the words Penstock Valve. It now refers to a pollution containment valve or pollution containment devices. Therefore, what you’re looking for now is a valve that actually seals. The danger is when you take the term Penstock, you’re actually looking at, as the English dictionary says, a flow control device. They are different. You’ve got a valve that’s quite slow that was designed to stay in place for many many years but to slow and control the flow, not necessarily isolate that flow.
What does a pollution containment valve do?
So, when you look at a pollution containment valve, which is ToggleBlok or a device that’s similar to that is, it’s there to immediately, or as fast as possible, stop a flow dead so it can not carry on down the pipework.
How do you trigger a pollution containment valve?
So when we look at our connected valves and ToggleBlok in particular, we’ve got it connected. It can be connected to a simple smartphone device, it can be connected to a button that somebody just presses, a remote button. It can be connected to your fire alarms. In fact, it’s actually endless. Anything that creates an alarm input can be used to operate a valve.
How much does a pollution containment valve cost?
So, what you’ve got is there’s a benefit by having an automated valve. It means it takes the human element out. So, if you’ve got a valve and you have a pollution incident you’re relying on a human being and something like a Penstock Valve or a simple manual containment device, somebody has to go and operate it. That means that the person needs to understand what they’re doing. If we then look at automated pollution containment devices, these devices are connected up to intelligent pieces of equipment. So, if an alarm automatically goes off, it shuts a valve. It closes a valve. It tells you that it’s closed the valve. It documents the time, the date when that valve was activated. So, you’ve got a chain to actually look at. So, if you did have a pollution release because something had happened you would be able to evidence to the regulator that the system you had in place was operational.
How do you decide where to place a containment valve?
So, the cost of pollution containment valves or systems can vary. It’s quite an open-ended thing, we are probably looking at a starting figure of about six thousand pounds that carries on upwards depending on how many pollution containment valves you need, how big they are, how complex the system is that you want to run them off. But this is nothing compared with looking at the cost and of automating and instaling a sizable automated Penstock System where you’ve got to get mains power and other sevices to it. These are quite an affordable piece of equipment but you must remember they are designed to isolate that drainage flow completely. They’re not really designed for controlling a flow, they’re there to stop a flow an the event of an incident, a pollution event, to make sure it doesn’t happen.
How are pollution containment valves powered, controlled and maintained?
So, installing pollution containment valves isn’t as simple as most companies think it is. What you need to understand is if you stop a flow, for instance, in a drain, where does it lift? Because it’s not necessarily you fit a valve at the end of a line and it will fill up and pop out at the other end of the line. Sites aren’t flat. Sites are different. So, if you put a valve in the wrong place what you could end up with is that a valve could hold no more than probably ten, twenty thousand litres of liquid which isn’t much if it’s raining at the same time as that pollution event. And it could pop out and find a pathway off the site through the natural roadway. So, what you have to do is understand the risk model of what the site looks like? What is the drainage underground network like? And then what is the above ground topography of the site? So you understand exactly where to put that valve. It’s really critical to know where to put a valve because it can make a real difference, as we have found at some sited where they have four drainage outlets, so they think they need four valves. When actually when you understand the model and the risk you find out they only actually need two. That can happen if you haven’t really looked at how the drains work on your site.
How easy is it to instal a pollution containment valve?
So, pollution containment devices, in my opinion, shouldn’t be connected into your mains supply and shouldn’t be reliant on some sort of back-up generator that’s got to kick in. You need systems like this to be totally independent. They’ve got to be standalone. So, we tend to use is battery power, we use solar energy, we use wind energy, whatever it is but we will not connect them into the mains. What we’re looking at here is a system that’s standalone because normally the valve needs to be placed in a location that you probably haven’t got services to in the first place. You need to keep it relatively simple because the majority of your cost of an automated Penstock Valve with a three-phase motor on it is actually getting the services to operate that valve. Critical to that though, in the event of a fire or a power failure is the valves that you need to operate when you have a pollution incident actually don’t have any power and that is totally the wrong way to go about it. Any pollution containment device needs to work without power. It needs to be able to operate off its own internal power source. When we make the valves now, ours actually tell you if there is a problem. So, if you have got a battery drained or you’ve got a battery that’s going into failure it will send you a message to say this system is going offline there’s going to be a problem if you don’t look at it in the next month you won’t have a system that’s operational. So, there’s all sort of controls put in place but you must always, with containment systems, they should be offline. They should be standalone.
So, as I’ve just said it’s the installation when you put in one of the ToggleBlok systems in, really what you’ve got is you’ve got three airlines. These three airlines are used to open and close the valve and then you’ve got another one which is how we know when the valve is in an open or a closed position which is important because if you’ve operated a valve you need to know whether it did close, or did it open after you’ve had an incident. If you start to look at that type of device you’ve got to get a duct. But a relatively small duct, it’s an unpowered airline so there’s only ever air on that system when it’s operational. The whole system is twelve volts, it’s relatively there for safety, you’re not going to get electrocuted. Whereas if you start to look at a control system, you’ve got to get mains power to it and normally that means you’re either going to get main’s power to an actuator below the ground which now you’re putting it into a chamber which could have gases in it at which point you probably need to look at Atex. So, you’ve got a much more expensive unit and you’ve got an explosion risk, a health and safety risk. So, all you’re doing here is looking to close a valve. So, make it simple. Make it so that all you’ve got is one function. Keep it simple by using a system that’s totally self-powered. Nice and simple. Small little three hundred square boxes that sit with a 10 Watt solar panel on it, fine. You can make power if you want, but we would always advise you not to.
So, a major benefit with fitting a standalone valve is, you’re not putting services to it. You don’t need to build a massive deep trench that carries these powered cable conduits. It’s nice and simple and because the valves we make are what we call modular, so they are very lightweight. If you take for instance a six hundred mill valve of a ToggleBlok side it’s something in its modular form that a person can pick up and lift. If you take that as a Penstock Valve you’d need a crane. So, the device you’ve got, once it’s in the ground it can actually come out again. It can be retrofitted to the existing infrastructure without it any real major design changes to the drain.
What is your recommendation for anyone looking to address their water pollution prevention issues?
I recommend that you follow our six-point process which is: understanding the regulations, understand the regulations that affect your business and how they’re going to affect your business, carry out a risk assessment fully assess\ what you actually need to do, and what are you trying to achieve: then, you need to make a design, create a design so you understand what that design is going to be, then build and install the design, put it in place, get it working. Finally, maintain, monitor and document the system that you’ve installed. Make sure you keep it up to date and well maintained. Don’t forget that as guidance changes, as products and new technology comes through you need to on top of it. You don’t need to just sit with the equipment you put in years ago. You need to keep up to date. So, if you need to know anymore, why don’t you contact us at www.penstocksolutions.co.uk.
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David Cole MSEE
Technical Director
David is a pioneer of the spill containment and water pollution prevention industry with 30 years experience. He was instrumental in the development of CIRIA736 with The Environment Agency and is passionate about preventing water pollution.