A Taste of What's Inside
Imagine you’re in the middle of a crisis, relying on your stored water for drinking, cooking, and cleaning. But when you turn on the tap, the water is murky, filled with floating debris, and has an off-putting smell. Not exactly the lifeline you were hoping for, right?
While we’ve already tackled invisible threats like bacteria and chemicals, this chapter looks at physical contaminants – those you can see and that can make your water unappealing and unsafe. We’ll explore how to identify these contaminants and discuss practical solutions to keep your water crystal clear, no matter the situation.
Sediment: The Gritty Truth
Sediment is a common physical contaminant in stored water that, while not always a direct health risk, can affect its quality and enjoyment. Sediment consists of tiny particles—soil, sand, silt, clay, and even decaying organic matter—that find their way into your water storage. These particles often originate in your untreated water source. Think about how rainwater runoff carries soil and debris from the surrounding land or how wind deposits dust and pollen onto the water’s surface. Even leaves and twigs that fall into your water source break down over time, contributing to sediment buildup.
If your storage tank or pipes are made of metal, rust and corrosion can also flake off and add to the problem. Human activities like nearby construction and landscaping or animal activity can also stir up sediment and introduce it into your water supply.
Why Sediment Matters
Even tiny amounts of sediment can significantly impact the safety and appeal of your stored water. First and foremost, it affects the aesthetics of your water. No one wants to drink cloudy or gritty water, and the earthy or musty taste it imparts can be quite off-putting. These issues can be especially problematic in emergencies where your stored water might be your only option for drinking and cooking.
Aside from unappealing taste or odor, sediment can also wreak havoc on your water storage and disinfection systems. It can quickly clog filters and reduce their efficiency. Needing to repeatedly clean or replace expensive filters during an emergency is an extra burden no one wants.
Even more concerning is that sediment can interfere with disinfection efforts. The suspended particles physically shield microorganisms from disinfectants, increasing the likelihood of live bacteria remaining in your drinking water.
Furthermore, sediment particles often carry other harmful contaminants, such as heavy metals and pesticides. By hitching a ride on the sediment, they can be transported throughout your water storage system and end up in that refreshing glass of water you’re trying to enjoy.
Practical Solutions for Keeping Your Water Clean
We’ve agreed that sediment isn’t welcome in our stored water, right? Now, let’s roll up our sleeves and look at some practical solutions to tackle everything from minor sedimentation to significant contaminant loads.
Mechanical Filtration
Pre-filtration
Pre-filters are the first step in removing larger debris from your water. They’re often made of simple mesh or screen filters and should be installed at your water’s source, whether it’s diverted from a river or collected using a rainwater harvesting system. Pre-filters capture leaves, twigs, insects, and other large particles before they can clog or damage more sensitive equipment downstream.
Settlement Tanks
Heavy sediment must be removed before it reaches your main storage tank to avoid damaging your pumps and other equipment. A simple settling tank installed before your primary storage allows you to do just that. Heavy particles sink to the bottom as water slowly flows through the settling tank, leaving minimal sediment to continue to the next stage.
Flocculation
Some particles are so fine that they refuse to settle on their own. Flocculation is an effective technique in these cases when used alongside other filtration or settling methods. Chemical flocculants cause fine suspended particles to clump together into larger, heavier particles that readily sink in the settling tank or can be filtered out in the next stage. Avoid using flocculants directly in your primary drinking water storage tank.
Sediment Filters
Sediment filters are usually the best option for removing any remaining fine sediment. They use fine mesh or pleated cartridges to trap tiny particles like silt and rust. They’re usually placed immediately before the intake to your storage tank.
Other Filtration Methods
While pre-filters and sediment filters effectively address physical contaminants, other specialized filters (always placed after sediment filters) can target more specific impurities. For example, activated carbon filters improve taste and odor by removing chlorine and pesticides. Ceramic filters, on the other hand, are most effective at eliminating bacteria and other microorganisms. (For a more detailed discussion of these filtration methods, check out Chapter 6.)
Integrated Water Quality Management
Maintaining water quality requires a coordinated approach that combines physical and biological treatment methods. Since physical filtration alone won’t eliminate all biological contaminants, a disinfection protocol is critical for drinking water. However, physical pollutants must be removed before disinfecting, as they can shield microorganisms from the disinfecting chemicals. We’ve taken a detailed look at treatment protocols for biological and chemical contaminants in Chapter 6.
Putting a Lid on It
Now that we’ve explored impurities like sediment and physical contaminants, you understand the problems they bring and are familiar with the most effective techniques for managing them. Now, let’s move on to the next chapter, where we’ll introduce liners, what they do, and why they’re essential for any water storage system.
