Every year people die by electrocution, and some of these incidents are associated with pools. In fact, In September 2016, a young girl working as a lifeguard at a swimming pool in North Carolina lost her life when she was electrocuted as she entered the water. So let’s talk a little bit about this, and how we might reduce the risk of electrical injury associated with pools.
Electrical energy acts a lot like other sources of energy in that it moves (flows) from one area to another when there is a “potential difference” in the voltage of those areas. Like a waterfall plummeting from a high point to a low point, so does electricity from a higher voltage (a live wire or battery terminal for example) to a lower voltage (ground).
Electricity generally speaking, needs a “conductor” to move or "flow" through. This flow of electricity is expressed in terms of Amperes or Amps. Some things are better conductors than others. Copper, aluminum and gold are excellent conductors and pass electricity, while things like the human body are less apt as conductors, but can certainly still pass electricity. Other substances like some (but not all) polymers and glass are insulators. Still others are classified as semiconductors (like doped / contaminated silicon). Uncontaminated water is actually an insulator when pure (distilled), but becomes sort of a semiconductor most of the time. In pools, it is usually a pretty fair conductor having been “contaminated” with minerals, chlorine and sometimes salt. The human body is a mediocre conductor, but also a poor insulator. Being that we are largely made up of contaminated water, electricity from a source will pass through our bodies on the way to ground…the lower voltage. On the way through it can interfere with nerve impulses including those activating the heart, and cause damage, seizure or in the worst case death by cardiac arrest.
So how can we make the seemingly unsuitable bed partners of pools and electricity less…shocking?
BONDING AND GROUNDING
Bonding refers to bringing all of the conductors around the pool (the reinforcing steel, handrails, light fixtures, pump cases etc.) to the same electrical potential by connecting them all together with a conductor (a ground wire). This eliminates the possibility of any potential difference between these various items; whatever voltage one item is at, the same voltage will be seen at all of the other items. But bonding alone does not render the items safe. You can’t get a shock between one item and another, but what if a stray voltage is energizing the bonding wire to some higher voltage? Then any of the items could give you a shock if your body is grounded (for example, being barefoot on the deck). To ensure the items are a zero volts, the bonded items have to be grounded. This simply involves running a wire from the bonded loop to the ground lug in the distribution panel.
KEEP ELECTRICAL ITEMS AWAY FROM THE POOL
It is never a good idea to have an electrically powered item near a swimming pool. Things like radios, blenders (for those summer margaritas) if dropped into the pool, can electrically charge the water and potentially shock bathers. Even if the device is away from the pool on the deck somewhere, someone who has recently been in the pool could drip water into the device and create a conductive path with the water from the device, through them to ground…not fun!
USE GFCI DEVICES AND BREAKERS
Ground Fault Circuit Interrupting (GFCI) devices work by comparing the current flow in the hot (supply) wire to the current flow in the neutral (return to ground) wire. In any circuit, the current flow should be the same in both ‘legs’. If it isn’t, it means the current is going somewhere else - like through you! The GFCI device will trip to disconnect the power supply if there is a difference of 6mA (that’s 6/1000 Amps), and does so in a fraction of a second to protect us from being shocked. GFCI devices are a great way to protect people from any electrical device, but are particularly appropriate for things like underwater pool lights where electricity is so close to the water.
PERFORM REGULAR ELECTRICAL REVIEWS
It’s a fact of life on this planet of ours that things change, materials degrade, corrode, erode, oxidize and just plain wear out. Your electrical system is no exception. Electrical distribution boxes and the breakers within become corroded and fail. Plastic wire insulation dries out and cracks, ground points become corroded. Corrosion is exacerbated by exposure to salt water because of its electrolytic properties. Having a reputable electrical contractor visit the site periodically may flag some of these issues before they become a health and safety concern. In addition to a visual inspection, they can perform tests (like high voltage meggering) to assess the condition of various electrical insulators in the system.
Salt Water Chlorination: Is it the Right Option for your Facility?
Wednesday, March 14, 2018
Salt or no salt? That is the question! Or at least one of the most common questions being asked by pool owners and operators these days. Every pool owner has their own set of reasons for wanting salt or not wanting salt. There are many questions regarding the mechanical equipment at the facility, finishes of the pool, uses of the pool, local bylaws, (just to name a few) that must be answered before jumping to any decisions. Additionally, the owner must be aware of the many myths regarding salt water systems and chlorine systems alike before making any decisions. They must also understand that a salt water pool doesn’t mean you will be swimming in ocean water! Windows to the Universe team states that salt water pools typically have 3,000 to 6,000 ppm, while the ocean is about 35,000 ppm.
When changing a liquid chlorine sanitized pool over to a salt water system, or when building a pool destined to be salt water, the mechanical systems must be selected properly. Everything from the pumps, filters and heaters must be designed and approved for use in a salt water pool. If this is not done, manufacturers will not honour warranties, and there will be damaged equipment much prior to their normal lifetime.
The finishes of the pool need to be considered when contemplating a salt water pool as certain finishes do not last as long under salt water conditions. Liners, tile and plaster finishes all have their own issues when it comes to salt, so owners must investigate each option thoroughly and ensure whichever option is chosen is installed properly. As with any sanitation system, monitoring and proper balancing is also very crucial in the lifetime of the finishes.
Fixtures such as hand rails, underwater lighting fixtures, and rope anchors need to be properly chosen when going with a salt water pool as they will corrode faster without being constructed of proper materials and properly maintained. The image above shows a hand rail in a salt water pool that is rusting due to the salt. Think of what salt use on our roads does to our vehicles and infrastructure during the winter months. The same type of damage will happen to a pool that doesn’t have all of its components designed for salt water use.
Primary uses of the pool under consideration for salt water should also be considered. A pool that is primarily for lap and competition swimming where there is high swimmer volume and high exertion may want to shy away from a salt system, as it will require much more monitoring of the chlorine levels to ensure they are in accepted ranges. Yes I said chlorine. Salt water pools still have chlorine in them. They use a chlorine generator system involving a process called electrolysis to produce its own chlorine, rather than adding liquid chlorine directly to the water. A therapy pool with low patron turnover may be a better candidate for salt water, as it will be easier to keep the pool balanced and may increase user comfort.
Local bylaws are another very important item to look into when considering salt water in your pool. Especially for commercial pools, salt is typically not permitted to be the primary source of sanitation. Most municipalities still require salt water pools to have a secondary sanitation system installed, typically liquid or tablet chlorination. Furthermore, when draining the pool, salt (and chlorine) levels usually must be brought down to low levels in order to legally be dumped into the municipal sewage treatment system. Always check local bylaws for your stipulations prior to draining your pool.
Pool owners need to ensure that they do as much homework on salt water chlorination as necessary to ensure that they have made an informed decision. There are too many cases of owners not taking all of the necessary steps required to properly operate a salt water pool, and have a seemingly endless repair bill. As with any large expenditure, always ensure you are working with qualified pool designers and builders when constructing a new pool or doing a renovation, no matter what sanitation system you are going with.
When planning the construction or renovation of your pool, whether commercial or residential, one of the many decisions you will need to make is the pool finish. There are several options available to both commercial and residential pools, there are also many factors to consider when choosing a finish. Cost is usually the first thing on everyone’s mind, when making any purchase. However, there are many other considerations that will often times outweigh the initial cost. The intended use of the pool is an important factor to consider when determining the finish of a pool. Residential pools, which have a lower use, can get away with one of the more budget-friendly options, as there is less wear and tear. A low-cost finish will save some money upfront however, repairs and refinishing will be required much sooner than some of the longer lasting, high-end finishes.
Tile has been used as a pool finish for years and is known to be the most durable finish. When applied correctly, a tiled finish can last for decades before requiring any replacement. Tile offers the pool owner a wide variety of colour options and design possibilities. Due to the preparation and labour required for installation, this high quality finish option comes at a higher initial cost. However, over time it will pay for itself, through the savings on repairs and replacements.
Durability & Longevity: A tiled finish will last decades if applied correctly, and compensate for the higher upfront costs.
Easy to Repair: If there is an issue with isolated delamination of tile, it is very easy to replace small areas of tile and match to the existing, without having to re-finish the entire pool.
High Upfront Cost: Correctly installing tile, comes with heavy labour including; the preparation of the subsurface, laying the tile and grouting the tile.
Deterioration of Grout: Though tile has a very long life span, the grout will deteriorate much quicker. Over time grout will begin to wear out of the joints and discolour. Normally, grout will be required to be replaced much sooner than the tile.
Plaster is one of the most prominent pool finishes around, and has been used for several years; a quicker install than products like tile is the main reason for its popularity. Plaster is shot onto the pool walls, similar to gunite, and then toweled to give it a smooth consistent finish. A plaster finish does require some sort of tile border at the waterline as the waves against the plaster will cause it to deteriorate quickly.
Cost & Durability: Even with the high level of durability a plaster finish offers, the cost is relatively low.
Aesthetically Pleasing: Plaster provides a very nice finish which is smooth and able to form to any shape or design.
Pool chemistry can very quickly deteriorate a plaster finish if not properly maintained; low pH in the water is a big concern and requires experienced supervision.
With age, pool plaster will start to delaminate and cause sections of the plaster to pop off, having to re-plaster a pool is very costly.
Painting a pool is a very inexpensive method of finishing any pool, and is typically used in a commercial application for community or public pools. Though painting a pool is an economical and quick finish option, over several years the paint will chip and need to be repainted. A parge coat is required before painting to ensure all honeycombing of the concrete is filled, leaving the floor and walls smooth.
Low Cost & Project Schedule: The cost of the material and labour required to complete the work is extremely low and can be completed quickly.
Low Risk of Damage: Since paint is applied to a cementations backing, there are no concerns about damaging or puncturing the finish from items in the pool.
Frequency of Repairs: A paint finish will need to be refinished every 3 to 5 years, requiring the existing paint to be blasted off before repainting.
Imprefections: If the subsurface of the pool is not done perfectly any imperfections such as honeycombing or rough parging will show through and can cause injuries to swimmers.
VINYL LINER FINISH
Traditionally Vinyl liners have been a typical residential pool finish, due to the relatively low cost and quick installation. Liners can and have been used for commercial applications however, due to the low durability of a liner it is not very common. Vinyl liners can be used in both stainless steel and concrete pools.
Low Cost: In comparison to other finishes, liners can be an economical alternative. The liner itself is relatively inexpensive, in comparison, and installation labour is a significantly lower cost.
Creates a Water Tight Tank: This benefit can be an efficient solution, saving time and money, to a deteriorating concrete pool, which has started to leak.
Deterioration: Vinyl liners are more susceptible to deterioration caused by harmful UV light and poor water chemistry, resulting in the liner needing to be replaced sooner.
Easy to Damage: Vinyl liners can very easily be damaged from foreign objects, such as tree branches or toys falling into the pool. Punctures in the liner will result in water getting behind the liner, causing the pool to leak and the liner to bubble out.