Ageing Infrastructure

What do you think is the most likely reason for a water grid shutdown?  It isn’t terrorism and it isn’t pollution. The answer is, the age of the infrastructure used to deliver the water or collect the sewage. Think about the city you live in. Chances are it has existed for hundreds of years, if not longer. Most cities water systems grow in phases. They keep adding to the network every year as the population grows. The end result is most cities have infrastructure that range from less than a year to hundreds of years and with many different materials. I have seen water mains made of wood in service as late as 2011. Like any piece of equipment it all has a useful lifespan, beyond that lifespan failures become increasingly more likely to be catastrophic. The result is a large volume and dollar amount of material and equipment that needs repairs or to be replaced.

Wooden Water Main circa 1909 source www.nytimes.com

Wooden Water Main circa 1909 source http://www.nytimes.com

Normally the stress on water systems comes from population growth.  A water main that was ok in the 1980’s may not be large enough for today’s population.  As cities infill and build higher density buildings they frequently overburden the water systems.  Either causing contamination or total failure of the system.

Older equipment is also more susceptible to natural disasters, terrorism and human accidents. These three things can break a new system too, however they don`t have to try as hard with the older systems.

Climate change is having an affect too.  As severe weather events are on the rise, storm sewers might be found lacking, as was the case in Calgary, Alberta and Toronto, Ontario recently.  The system was grossly undersized for the amount of rain that fell.  They said things like “it was a month’s worth of rain in one day” on the news.  When the fact is, it once was a months worth of rain, and is now something more frequent, lets say a weeks worth of rain.    I’m not suggesting we build our systems to meet a 1000 year storm, but I am suggesting that our current idea of a 100 year storm may be an underestimation and that the error is getting worse.  To bring it back to infrastructure, if we are built to the current 100 year storm levels, what happens if the 100 year storms are getting worse?  We will find out in the not too distant future.

Calgary, Flood, Floods, Water

Flooding In Calgary AB 2013 source: http://www.newinfills.ca

What are the options for people to take? The first and most important thing to do is to plan ahead and replace older parts of the system before they fail.  A $50,000 job to replace an old section of pipe at a time you choose is a lot cheaper than waiting for it to fail at the time you are least prepared.  If you are connected to a public utility, ask them about their equipment replacement plan.  If they are not looking 25 years into the future or longer then ask them why not? If you have private systems, you need to ask the same questions.  Can you afford to replace the septic system when it fails? Or can you afford to dig/drill a new well when the casing cracks?

As you can probably surmise the addition of more people + more rain + more water and more sewage means system failures will become more frequent and probably for longer periods of time.  What does this mean to the average person?  Plan for system failure.  Have a backup system ready to go when it does.  Know the age of your equipment and it`s expected lifetime. That way you wont be caught off guard.

Septic Tank Problems

Septic systems range from the very simple to the extremely complex. Even on the simplest septic systems there are still many things that can go wrong. If you believe that septic systems are something you bury and forget about, then I guarantee that you will come across many of these problems. There are simple things anyone can do to keep their septic system running properly for decades.

First a general description of a septic system. The system starts where the common drain leaves the house. This drain can go to a municipal sewer or to an individual septic system. The water flows by gravity into the septic system. The inlet to the septic tank is protected by a T shaped baffle. It is open on the top and bottom. It is designed to contain floating debris in a small area and to direct solids to settle down towards the bottom. The water is contained here where solids settle out to form a sludge layer and floating objects form a scum layer. In between there is a clear zone where the water has very few solids. The water in the tank is treated by anaerobic bacteria. The bacteria break down organic compounds in the water until there is almost nothing left.
The water leaves the tank through another T shaped baffle on the other side of the tank. This one goes down to the clear zone and allows clear zone water to exit the tank without coming into contact with the scum layer. Some tanks have a septic pump, the pump is installed on the opposite side of the inlet and at the expected height of the clear zone. Larger tanks might have a dividing wall to keep sludge and scum on one side and clear water on the other side.

Septic Tank, Septage, scum, sludge, clear, zone

Basic Septic Tank Design (source: biozoneseptoc.com)

The sludge layer if not removed every three to five years can cause a major failure of the entire system. Not everything can be broken down completely.  There are always things that either never breakdown or breakdown too slowly and they accumulate.  The sludge layer will eventually reduce the capacity of the tank and the solids will block the inlet or the outlet of the tank.  The sludge layer will be a rapid problem if the people using the system treat the toilet as a garbage can.

The scum layer is all the floating solids the get flushed into the system. Grease and oils cause a large part of the scum problem. But they are far from the only culprits. Cooking oils and grease coat the walls of the pipes and tanks and slowly reduce the size of the of the inlet and outlet eventually blocking them, and you can see how that is a problem.

The drain field is where the treated effluent gets released back to the environment. It may be called something else like a tile bed or weeping tile. They are usually subterranean but can sometimes be on the surface. Regardless there are still buried pipes and they are easy to collapse if you drive a vehicle over them. Lawn tractors are OK but even compact cars are too heavy for the shallow plastic piping. If the piping becomes cracked or even a section collapses then pipe will become blocked with dirt and your waste water will have nowhere to go except back into the house.

Hydraulic overloading is the technical name for putting too much sewage into your septic tank.  This can happen if you have a party and there are more people using the system or if the sludge layer reduces the capacity of the tank.  The end result of overloading is that poorly or untreated sewage leaves the system negatively impacting the surrounding area.

Leaks are bound to occur with age.  You can also create leaks by driving over the tank and excavating too close to the tank.  Leaks are a huge problem once they occur.  The groundwater and soil contamination is extremely expensive to clean up.  You may also be liable for damage to the neighbor’s water supply depending on the riparian laws where you live.  A leaking tank needs to be replaced immediately.

Proper maintenance will prevent most problems.  The worst thing anyone can do is to bury the septic system and forget about it.

Can I use a storm-water pond as a back-up source of water?

Storm-water ponds are the closest alternative source of water for many people living in urban areas. In an emergency this source of water may be all that is available to you.  Eventually any water you have stored will be consumed and the water in a storm-water pond may be the difference between life and death.  With the proper treatment your local storm-water pond can be a great backup source of drinking water.

Industrial storm-water pond (source: info.evergreen.ca)

Storm-water presents a unique set of challenges during treatment. Because storm-water ponds collect surface water, the water is exposed to all the contaminants on the ground in the catchment area. This includes but is not limited to pesticides and fertilizers applied to lawns, motor oil and gasoline leaking from vehicles and litter like cigarette buts. It all ends up is the storm-water pond. Those chemicals are already in storm-water ponds on a normal day. During an emergency there may be additional contamination from sewage runoff from an overloaded or broken sewage system. The water in the pond will also contain all the microorganisms like ecoli, giardia and cryptosporidium normally in surface water. Any one of these will make you very sick if you get infected with them.
Finally, there will be high levels of nitrates in storm-water ponds. Too much nitrates consumed by young children can cause blue baby syndrome.

The first step in treating water from a storm-water pond is straining. Straining the water through a cloth or loose sand filter will remove large particles (ones you could pick up with your fingers). Remove as much of the suspended particles from the water as you can. Straining the water first will extend the life of your proper water filter.

If you have a clarifying agent like aluminum sulfate, this is the best time to add it to the water.  It will make contaminants too small to be filtered become attracted to each other and become significantly larger.  Larger particles are easier to remove from the water. Let the water sit still for at least 30 minutes without disturbing it.  All the newly formed large particles (called floc) will sink to the bottom.  When you take the water from this container, make sure you leave the majority of the settled material at the bottom of the container.

Urban Storm-water pond (source: greenbmp.blogspot.com)

The next step is to filter the water. Filter the water even if it looks clear, the human eye is five times too weak to detect dangerous levels of particles. Filter the water at least once through an activated carbon filter. Activated carbon is known to remove many different chemicals from water including pesticides, chlorine and fluoride. Activated carbon is not the same as charcoal. Charcoal is similar, it can remove toxins from water but it is nowhere near the efficiency of activated carbon.

The third step is oxidation. Oxidation will help with disinfection as most disinfectant chemicals are also oxidizers. Chemicals like sodium hypochlorite and potassium permanganate are both oxidizers and disinfectants. Oxidation will break down many of the remaining contaminants and inactivate many of the remaining bacteria. Keep adding the oxidizer/disinfectant till you can detect a residual after 20 minutes. The 20 minutes is the minimum you should wait for a gallon of water. Wait longer for larger volumes. This is because oxidation is a chemical reaction that isn’t instant. It needs time to complete the reaction.

The fourth step is to filter the water again. Filtering again is necessary because the disinfection/oxidation step will create some potentially carcinogenic byproducts. We filter before oxidation to minimize the amount of chlorine (or other chemical) and to limit the possibility of forming dangerous byproducts. We filter the second time to remove any byproducts that have been formed.

The final step is to boil the water.  This will help with disinfection, but the main goal of boiling at this point is to remove any volatile chemicals.  Any chemical with a boiling point lower than water will be removed after boiling.

A note about disinfection.  If all of these steps are followed there is no need for a step dedicated for disinfection.  Between the oxidation and the boiling of the water any microorganisms will be inactivated.  If you are storing the water for a long time then add some sodium hypochlorite for a residual disinfectant.  The residual disinfectant will prevent the water from becoming recontaminated before you drink it.

One additional possible step is to aerate the water.  Ponds are frequently stagnant.  Stagnant water is green with algae, it smells bad and tastes worse. After the water is made potable, transfer the water back and forth between two glasses. This adds oxygen to the water and will make the water taste better.

This may seem like a lot of work for something as small as a storm-water pond.  What I have described are the basic steps to turn the potentially toxic water in the pond into clean and safe drinking water.

Water Preparedness: Common Beginner Mistakes

Are you thinking about starting to store water? How about emergency water treatment? Getting started can be a very daunting task. Where should efforts be focused? What pitfalls should be avoided?  This article will explore a few of the mistakes I see people make when they start to take their personal water security seriously

Don’t be left without potable water. Avoid beginner mistakes. (source: always foodie.com)

The very first thing to learn is that there is no magic bullet. There is never a single product or technique which will always make water safe to drink. Combining, knowledge, multiple storage/treatment techniques and multiple products for storage/treatment is the best way to guarantee a safe source of drinking water for yourself and your family.  This logic or philosophy of combining as many protections as possible is used by municipal water systems all across North America.  It is referred to as a multi-barrier approach and it boils down to having many different protective measures to prevent contamination, in the event that one barrier fails, there are still many others in place.  To put it in layman’s terms, when it comes to water security, it isn’t a good idea to put all your eggs in one basket.

Marketing campaigns will make all sorts of claims about water products. Some will be irrelevant, like claims of BPA free plastic when the product is made from a type of plastic that never had BPA. Other claims will be over stated. The claim that is most often overstated is the number of times a water treatment product can be used. The quality of the water being treated is too variable for any company to give you an absolute number of times. This might not be done to deceive you. It could just be that the water they tested the product with was easier to treat then your water. Remember that no product will make the water perfect.  They will make the water safer when used correctly, if used incorrectly many water treatment products can make the water significantly more dangerous to drink.

Water needs to be stored in an appropriate container. This container needs to be able to physically hold the weight of the water and not leach any chemicals into the water. Assuming any garbage can sized container is appropriate will at best lead to soggy disappointment and at worst a severe case of gastrointestinal disease. For more information on water storage, read The Why? How? and How Much? of Water Storage?

Once your water is stored it needs to be kept safe. Water can become contaminated at any time. Anytime the container is open there is potential for contamination to occur. Read this article to find out what to do when your backup source of water becomes contaminated. The assumption that water only needs to be treated once is false. What was once safe to drink may be very dangerous when you need it if your aren’t protective of your supply. Water can turn stagnant when stored for long periods of time. Stagnation while not a health hazard is a taste hazard. Stagnant water tastes bad. Adding air to the water is how you relieve stagnation. Adding air is as simple as passing the water from one glass to another repeatedly or stirring the reservoir. The goal is to increase surface contact between the atmosphere and the water. It is important that aeration of the water will also remove the remaining chlorine (if any was present) in the water. If you are aerating the reservoir make sure you add some more disinfectant. Do this so you can keep your disinfectant residual high enough to keep the water contamination free.

Another mistake people make, is they store water but make no changes for reducing the water they use. Forgetting to change behavior during a crisis is probably the biggest mistake beginners make. Different situations require different behavior, this applies to your personal water use. You will be amazed at how much water is used if you aren’t careful. What could last a week might be used in a day and then you will understand the true value of water conservation. This mistake can also happen in more than just your water use.  For more information on water conservation read why water conservation is a prepper’s must do.

The single biggest mistake beginners is they assume that they can learn how to treat water later. Later becomes too late and then it can become fatal. It is very difficult to learn something complicated like water treatment when your life depends on it. Learning as much as you can before an emergency strikes is the single best thing you can do to stay safe.

This article covers just a few of the common mistakes I see people make when they start taking their water security more seriously.  There are many more mistakes that can be made and no one person has the perfect solution to them all. Water security is something that needs to be tailored to each person or family’s needs.  Have you found any common mistakes while preparing for water shortages? If so, leave a comment below, I would love to hear them.

Lead (Pb) In Your Water?

I get asked a lot of questions about lead in water supplies. Questions like how dangerous is it? Or how much is present in their water? Or where does the lead come from? And what can individuals do to remove lead from their drinking water? Since lead can cause brain damage when ingested, these are all very important questions that need answers. Be careful of the dates in this article. They will vary largely depending on where you live as different jurisdictions banned lead at different times. Another thing to note is that on average drinking water only counts for 20% of American’s lead exposure (according to the EPA) and total exposure is what causes health problems.

Soruce: science.howstuffworks.com

Lead can be very dangerous in water supplies. If consumed in large enough quantities it can cause severe brain damage, kidney damage, anemia and there is some evidence that lead can cause high blood pressure.  Compounded on this brain damage is what happens to the larger community if everyone is drinking lead contaminated water and significant percentage of people are suffering from lead poisoning. Costs for healthcare (monetary or increasing disease) increase significantly with lead exposure and with that a decrease in quality of life.  They younger you are the more lead exposure affects you (including before you are born).  This is because growing children absorb more lead from the food and water they drink. Also because they are smaller, they can hit toxic levels sooner.  Finally, lead has a cumulative effect on the body. Your lifetime exposure determines if there will be any negative health effects.  Some lead will remain in your bloodstream for the rest of your life, and most will end up in your bones.

If you are on a large municipal system there is a good chance the monitor for lead. In Ontario, Canada, the Provincial government forces every municipal system to test for lead twice a year throughout the system. Any sample that exceeds 0.010mg/L will be reported immediately to the local health unit the ministry of environment. The resident will be informed shortly thereafter. If you are curious about lead levels you can find the results in the Annual report for the municipal water system. If you are more proactive you may even be able to volunteer your home as a sampling point for a lead testing. Failing that you can always send a sample to an environmental laboratory.  Calling your municipality will get you the information of what they are doing to control lead.  They have more options available to them than any individual does.

Lead gets into water supplies in three main areas. Into the source water from natural deposits or from lead based pollution. Finally, and by far the most significant source of lead is from plumbing with lead based metal fittings. Many alloys contain lead. Even lead free metal fittings can still contain lead and even buying top quality fittings still poses a lead risk. Any solder made before 1986 likely contains lead, sometime upwards of 50%. If you live in an older home (pre 1930’s) there is a chance that you have a lead service connection and possibly lead plumbing.

Homes less than five years old also can have lead problems because the water has not coated the internal plumbing with scale. Scale is a build up of minerals on the wall of pipes and reservoirs that physically separates the water from any potential lead.

Lead Pipe and Copper Pipe (source: winnipeg.ca)

Lead was used so frequently because it is very easy to form into useful shapes. Shapes like pipes, valves and curves. Lead is very soft, that’s my it can make so many useful shapes easily. Lead on it’s own is often too soft for retaining the shape you want, especially if there is any stress on the metal. However mixing lead with other metals like brass, make the brass easier to work with and give the lead more rigidity. Copper was mixed with lead a lot less often then other soft metals. This is one of the reasons pipes were switched to copper. However fittings are still often made of brass because it is easier to make complex shapes like valves in brass. Remember that even “lead free” brass still has some lead in it.

Because lead is in older solders, flux and metal pipes, most of the lead enters the water while sitting in the household plumbing. Typically overnight when the water sits still in the pipes for at least a few hours. Lead needs time to be absorbed into the water (or leached from the metal). The longer water touches anything with lead in it the more lead enters the water. Lead absorption is also influenced by pH. The lower the pH (more acidic and therefor more corrosive) the greater ability the water has to remove lead from other sources. Raising the pH will help reduce the amount of lead that leaches into your water, it will also encourage scale formation. You can mimic corrosive water by grounding electrical systems to metal plumbing.  Grounding electrical systems to your plumbing is bad for your plumbing and helps lead enter your water.  BUT PLEASE GROUND YOUR ELECTRICAL SYSTEMS SAFELY AND ACCORDING TO CODE.  Temperature also affects lead absorption. The hotter the water the more likely there will be lead in the water and the water’s ability to carry water increases.

Scale Formation In Copper Pipe (estimated 20 years of scale growth) (source: ryan-technology.com

So what can you do about lead in your water? First, get your water tested. Knowing there is a problem is essential because you can’t see, taste or smell lead dissolved in water.
Second, always flush until the water is as cold and stops getting colder. If your home is older than 1930 and you don’t know for sure that your service connection isn’t lead then flush for an additional 15-30 seconds to make sure you are getting water from the street. This flushed water doesn’t have to go to waste. It can be used for non-consumption purposes like washing and gardening.  Flushing may not be a viable option for you if you live in a high rise building as the pipes may be too large for you to flush economically.
Third, never use the hot water tap for consumption purposes. It is better to boil cold water if you need hot water.  Lead affects children and pregnant women significantly more than it does grown ups.  Small amounts of lead that are harmless to a adult, can be highly toxic when introduced to smaller bodies.  You can buy a water filter that is capable of removing lead from water.  If it is not specifically designed to remove lead then there is a good chance that it doesn’t remove much lead at all.  Because lead has been such a big issue in the past, there are a lot of fake and ineffectual “lead” filters out there.  Double check the manufacturers claims with independent information or get the water tested.  Don’t forget to change the filter often otherwise you will expose your water to VERY high levels of lead.

Water Survival During the Zombie Apocalypse

First off a bit of a disclaimer, I am fully aware that zombies are not real.  I am however highly entertained by zombies and all things undead.  Since the Omega Man Journal is about water and survival, that lead to the obvious thought experiment of what challenges a zombie outbreak would have on our ability to get safe drinking water.

Zombie, Zombies, Undead, Scary Zombie,

Zombie Rage Face (zombieambience.com)

The first thing to appear after the dead rise will be panic. Fear will be rampant and many people will be operating on their fight or flight instincts others will be holed up at home. This includes the people who work at municipal water treatment plants. Water facilities, although automated still depend heavily on people to operate them. When those people stop going to work or are already zombie chow then the water will stop shortly thereafter. To see what it would look like when a water system gets shut down and roughly how long it would take read Grid Shutdown: How Long Will The Water Last. The same will be true of the sewage systems. Read Grid Shutdown: Why Is There S#!t In My Basement, Sewage Emergency: Thunder Bay Flooding and A City Without Sanitation to see just how disgusting our once clean (or not so clean) cities will become.

Zombie, Horde, Zombie horde, the walking dead, set pictures

Zombie Horde (geektyrant.com)

Speaking of sanitation, people will die from unsanitary conditions. That means dead bodies, not just zombies, but regular dead bodies. Cholera is an excellent example of a waterborne disease that is a direct result of decomposing animal tissues in a water supply. Thirst will drive people to the nearest supply of water, then many will die on the banks and contaminate the lakes and rivers. Remember at this point I’m not talking about zombie contamination of water sources. That’s coming up later. This is a real danger when thirsty people or animals die in water supplies.

Depending on how zombies are created there may be a serious water vulernability. There are already bacteria, viruses, parasites and other micro-organisms that use both water and human bodies as part of their natural life cycle. Typically we call the effect of these micro-organisms “water borne disease”. Also there are already parasites that can take control of other organisms even to the point of making the host suicidal. Specifically there is a fungus that will radically alter the behaviour of ants turning them into zombie ants. (read more about zombie ants).  We are talking about total control of the host for the benefit of the parasite. Finally there are countless micro-organisms and insects that thrive and depend on rotting flesh to survive either for food or as a vital part of a life cycle stage like maggots turning into flies.

Bacteria thrive on and cause decomposition of deceased organic matter

Those three characteristics which already exist, put a zombie making organism on the edge of being possible. Nature has already made all the organisms necessary to create a zombie, luckily for now the necessary skills are in different organisms and target different organisms. The problem is, if nature caused one organism to eat rotting flesh, it can teach another organism to do the same. Same thing with learning to disperse through water and to take control of other organisms.

Zombie Ant With Fungus Growing Out Of Its Head (nationalgeographic.com)

Let’s assume this is the cause of zombification, what then can anyone do to protect themselves? The good news is that modern water treatment is very good at removing and inactivating micro-organisms. The combination of chemically assisted filtration and disinfection should (if done correctly) remove 99.999% of micro-organisms. Depending on the size of this fictitious zombie bug/parasite/virus it might be possible to remove even more than 99.999% if it is on the large end of the size scale. If it is a virus, which is the smallest type of micro-organism then removing 100% of the z-virus will be next to impossible. That means we better hope that there is a disinfection method that can kill the virus either chlorine, UV, ozone or boiling.

Zombies Again (beyondhollywood.com)

One thing many people haven’t thought about when they are talking about zombies and water.  Water is very heavy.  If you have to haul water from its source to your secure facility it will become very difficult to run at the same time.  Now vehicles are an option as are hand carts and if you have the resources pumps and pipes are best.  Just remember that they are all noisier and may attract unwanted attention from nearby zombies.

Those are some of the challenges I see affecting our ability to drink safe potable water in the event of a zombie outbreak.  I tried to be as true to real science as is possible when talking about zombies.  At the very least I hope you were entertained.  Can you think of anything I missed?

Grid Shutdown: Boil Water Advisory

If you have ever had a water main break on your street or any other service disruption to your water supply you may have experienced a Boil Water Advisory or a Boil Water Order. Boil water advisories/orders are the official response from the people running the water system. Below is a brief description of when a system would issue a boil water advisory or order and some general ideas for what should and should not be done as someone under a boil water advisory/order.

Source: districtgov.org

The good news about a boil water advisory is that they are often issued as a precautionary measure. Meaning they are often used in cases where the water isn’t actually dangerous. The system operators issue the warnings so they have done the proper due diligence. The liabilities involved if someone gets sick or dies and the public wasn’t informed are huge. Ok, at this point you may be wondering what sort of situations would require a boil water advisory. Typically any time there will be work on the distribution system requiring lowering the pressure or if the disinfection of the water system is interrupted for a long time.

Boil water orders are more serious. They come into place when large and persistent problems occur. Things like contamination of the source water and major failure of critical treatment equipment can cause boil water orders.

Boil Water Notice From The Regional District Of North Okanagan (source: vernonblog.blogspot.com)

The first thing you should do when you learn about a boil water advisory or order is read the information given to you. It will have instructions for you. It will have essential information for you like the cause if it is known and the expected duration. It will also list acceptable uses of the water, you might need to boil before drinking but washing is fine. Or you may not be able to use the water for gardening if the reason is due to chemical contamination. If you actually read the notice you will appear to have inside knowledge because in my experience very few people will ever read them. It will also list sources for alternative drinking water supply. Watch how fast the corner store sells out of water. In my experience, people only let this happen once. Then they start keeping a supply.  The written notice will usually only talk about “drinking” but the list of activities that require boiled water include food preparation, coffee makers (some don’t boil the water long enough or hot enough), brushing teeth, making ice, making infant formula and anything going into an immune compromised person.  Veterinarians also recommend that any water given to a domesticated house pet should also be boiled.  Livestock are a different story.  Anything that is already free range is already drinking untreated water and will probably be unaffected by drinking the unboiled water.  However, there is still a limit for bacteria concentrations in water consumed by livestock, free range or not, just like there is for every other animal (including us) on the planet.  Here is a link to the standards for water uses for the Province of British Columbia, use table 1 as a guidline for how to use water during a boil water advisory or boil water order.  If table 1 says “no applicable standard” then it is safe to use the unboiled water. http://www.env.gov.bc.ca/wat/wq/BCguidelines/microbiology/microbiology.html#toc

The biggest thing you should not do is abandon drinking tap water in favor of bottled water. This is a mistake. If you do this you are still at risk but you are significantly less likely to hear about it if something is wrong. Another thing to avoid doing is panic. This is one of those things where no news is good news. I tell the people that if you stop seeing me and hearing from me then everything is back to normal. This is because I am legislated to tell the public when there is a problem. At this time I also tell them the time line as does the written notice. After two consecutive clean water tests the system and water return to normal. It is also way too time and cost prohibitive to go back door to door and say “everything is fine now”.
If you live in a large city, there will probably be some media coverage of the return to normal situation. Otherwise if you don’t hear anything. After the date on the notice your water is fine. If there is still a problem they are legally required to tell you again about the problem.  Neither a boil water advisory or boil water order is something to panic about it is not time to call a well driller and go off the water system completely (if that is even an option where you live). It is time to start using your preparations and your backup water supplies.

If you don’t want to or can’t boil your water then you can always use an alternative form of disinfection.  Either ultraviolet radiation, sodium hypochlorite or calcium hypochlorite are acceptable alternatives.  Be careful of using these alternatives for highly turbid water sources.  The floating debris in the water can hide pathogens, cryptosporidum is highly resistant to chlorine as is girarda adding enough chlorine to kill these two microorganisims will make the water unsafe to drink.  Turbidity can also react with the chlorine to form hazardous chemical byproducts. Remember turbidity is removed from the water by setteling and filtering before disinfection to avoid these two problems. You may want to install a water filter in your home or purchase a portable water filter as a backup.

All that is left is what needs to be done after the boil water notice or order is lifted and everything returns to normal.  Flush all water-using fixtures like faucets and showers for at least one minute. Drain and flush all ice-making machines in your refrigerator. Run water softeners through a regeneration cycle.  Drain and refill hot water tanks set below 45 C (normal setting is 60 C). Change any filters either under sink style, on the faucet style and the ones in a jug in the refrigerator, regardless of the type of filter.  Filters that are designed for untreated water will not need to be changed unless they are used up.