Where Should I Drain My Hot Tub Water? (Avoid Hefty Fines!)

Draining your spa water in the wrong place can lead to hefty fines and a whole lot of other problems. Fortunately, it’s not a complicated affair and just a case of knowing the dos and don’ts.

In most cases, the best place to dispose of dirty hot tub water is in the sanitary sewer outlet on your property. Another popular option is to empty the wastewater onto the lawn in your backyard. However, care needs to be taken to ensure that the sanitizer level is reduced enough to avoid damaging the grass.

This article will cover:

  • Important information for disposing water safely and legally.
  • Why you shouldn’t use storm drains or septic tanks.
  • How to prepare spa water for drainage.

Sanitary sewer

One of the most suitable and fastest ways of draining hot tub water is by disposing of it in the nearest sanitary sewer. However, you must follow laws pertaining to spa water drainage in your city as each district has its own standards that must be met.

Unlike storm drains, sanitary sewers transfer the wastewater from your hot tub to a treatment plant where it is purified of harmful substances. 

Wastewater from different parts of your house, including showers, taps, washing machines, and toilets, all end up in sewer systems, so it’s only logical that your used tub water follows suit.

You may be wondering if it’s possible to drain hot tub water into a sink? Yes, you can. Any water poured into a sink ends up in the sanitary sewer, so it’s perfectly safe to use if there is no direct access to the sewer outlet.

Apart from your sink, you can drain your hot tub water using other sanitary sewer systems within your home, provided there is no direct connection between your hot tub and the sanitary sewer.

A better option would be to connect your spa directly to the sewer system. This can be done as a DIY project or through the assistance of a licensed plumber. A professional plumber would also be helpful in case you ever back up the sewer system.

When draining into the sewer system, keep the outflow to around 12 gallons (45L) per minute or less as sewer lines haven’t been built to deal with large quantities of water all at once.


Another way you can drain your hot tub water is by emptying it onto your lawn. It’s also a great way to recycle water. However, before draining, you want to reduce the level of chemicals in the spa, such as chlorine or bromine.

Note that draining onto a lawn is only suitable for chlorine and bromine hot tubs. You should never drain saltwater spas on grass. The sanitary sewer system is a more appropriate drainage method for saltwater hot tubs.

Sanitizers and other chemicals are dangerous to both plants and humans. You may have noticed that your skin starts to feel dry after staying in chlorinated water. That is the effect of chlorine.

Similarly, chlorinated water can dehydrate the grass, tree roots, and plants in your backyard, and hydration is a crucial part of plant care.

Before draining, you need to wait until the sanitary levels of the tub water are very low, preferably less than 0.1 parts per million (ppm), to avoid any damage to your yard.

Chlorine levels naturally dissipate after a few days; however, you can speed up the process by utilizing the hot tub jets, turning off the heater, and uncovering the tub to allow ultraviolet rays from the sun to destroy the chemicals as they evaporate.

Another thing to note is the pH level of the water. Acidic water is harmful to grass, so ensure the water’s pH level is neutral (between 6.5-7.0 pH) before pouring it onto your lawn.

It would be wise to use a hose or drain plug to gently release the now sanitizer-free water into the backyard, thereby easing the plant water absorption process and avoiding any risk of flooding.

This will also allow for proper distribution rather than pouring everything at once and over-saturating a single area.

Avoid storm drains

When draining wastewater from your hot tub, it’s best to avoid storm drains completely. Some municipalities do allow draining into storm drains if the chlorine level is below 0.1 ppm (0.1 mg/L).

However, any chloramines present in water can still damage the environment, which is why I recommend avoiding the storm drain to err on the side of caution.

Also note that some cities provide a special drain for easy access to a sewer system in your home, but do not confuse this with a storm drain.

Storm drains convey water directly into natural bodies like streams and rivers, where aquatic life resides.  This water passing through the drain doesn’t undergo treatment. Therefore, it still contains chemicals that can harm plants, fish, and other organisms living in the water ecosystem.

Water from your spa contains all sorts of chemicals like bromine, chlorine, algaecides, chloramines, salt, nonylphenols, and other pollutants harmful to marine life.

You may be thinking to yourself: if I can’t drain my spa water into the storm drains, where then can I empty my tub? Can I drain my hot tub into the street?

The purpose of storm drains, as is evident from the name, is to drain streets of rainwater and melted snow, and direct the excess water to reservoirs or streams nearby, thereby preventing flooding.

So if you dump your spa water on the street, you’re basically disposing the water into storm drains, and this is no different from walking up to a nearby lake and discarding pollutants into it.

Because of how damaging it is to the environment, there’s a fine for anyone caught doing this. The penalty for such an offense is around $1000 and increases for repeated offenses.

Never use a septic tank system

Septic systems and hot tubs don’t mix. You should never drain hot tub water into your septic system because it can cause a lot of damage.

Most tub owners don’t realize this, so they connect their hot tubs to the underground structure in an attempt to purify the spa water. Doing this has two negative impacts.

Firstly, the chemicals in the spa water are highly chlorinated and, as such, can kill the bacteria in the septic system tank. These bacteria are responsible for eliminating pathogens and breaking down solids in the tank.

Since they’re living organisms, they require a suitable environment to function. The chemicals in your spa water, ranging from sanitizers to alkalinity enhancers, can destroy these organisms, rendering your septic tank useless.

Secondly, since hot tubs typically carry a lot of water, emptying an entire spa into your septic tank system will push all the solids to the drainfield, leading to clogging of your pipes and ultimately ruining your septic system.

How to lower chlorine or bromine levels for safe drainage

There are two ways to lower sanitizer levels for safe drainage:

Using neutralizer: This is the fastest and safest way to lower sanitizer levels. NeutralizerOpens in a new tab. contains sodium thiosulphate, which is an inorganic salt compound that can rapidly decrease chlorine levels. 

Naturally: This is the simplest way to lower chlorine levels in your tub. However, it’s a much longer process than using a neutralizing product. It’s done by uncovering the hot tub, turning on the jets, and allowing the chlorine to reduce naturally over the course of a few days. 

Before draining the water, use test strips to check the chlorine level to make sure it reads 0.1 ppm (0.1 mg/L) or lower.

Joshua Milton

Joshua Milton is a seasoned hot tub enthusiast. With many years of experience in the industry, he offers valuable insights on hot tub maintenance, health benefits, and relaxation techniques.

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