Cesspools were built on Maui prior to 1991 for individual home wastewater disposal in rural areas where there was no municipal sewer service. In its most basic and traditional form a Cesspool is a hole in the ground to receive sewage: sometimes the walls of the “hole” are lined with stone or concrete to form a pit into which sewage is discharged. Solids remain in the pit, effluent (liquid) is absorbed into soil below and at the sides of the Cesspool. Solids settle to the bottom, floating grease and scum collect at the top, and liquid seeps into the ground, most of the time through the bottom of the Cesspool. The problem with Cesspools is that the liquid seeping into the ground has the potential to contaminate the ground water & our drinking water. The Hawaii State Dept of Health has required the use of septics after 1991 to protect Maui’s ground water resources where most of our drinking water originates. A few septics were installed on Maui prior to 1990. These were mostly in Kihei and Maui Meadows. It was easier to install a shallow septic than it was to blast through rock to put in a Cesspool. Many of the early septics used an injection well for effluent disposal instead of a seepage pit. An injection well is simply a water well that has water going into it rather than being pumped out. More information on septic systems can be found by clicking on the “Septic Systems” tab to the right.The Maui County Public Works standard detail illustrated Cesspools to be six feet in diameter and 20 feet deep (there is an illustration in the back of the Maui County Public Works publication).

This was a hole in the earth with a concrete cover on it. I must interject at this point, that I have never in 30 years seen a “standard” Cesspool. They are all different shapes and sizes. Most are excavated with a backhoe whereas the Public Works Cesspool was dug with a crane and a clamshell bucket. If the sewer pipe between the house and the Cesspool is two feet deep at the cover leaving an 18’ depth, the volume will then be 3,800 gallons. Back in the 80’s everyone had a backhoe in their carport and they were all digging Cesspools. Some used precast concrete covers, others were poured in place. A typical poured cover had eucalyptus logs or railroad ties/rails laid over the excavated hole and roofing metal over that. The concrete was poured on top of that. Some, but not many, had the foresight to make a plug from which to pump. These are the Cesspools where we typically need a jackhammer to break through the concrete and then, if we are lucky, the logs have rotted and fallen into the Cesspool so we don’t have to cut them with the chain saw. Of course, by the time we break the concrete, sewage is flowing out so a saw can be a lot of “fun”. Cesspools placed in sand or loose soil usually had concrete liners or hollow tile supporting the cover. I used liners at my house and placed filter rock around the liners to insure I would never have a problem. You get what you pay for. Maui has many different soil types which determines how well a Cesspool is likely to perform. Porous rocky soil in Hana will allow water to percolate at a rate of one minute per inch where Haiku clays may require 300 minutes per inch…when it is not raining. Some locations may vary from lot to lot. Take Pukalani Terrace, for example. Some Cesspools are dug and only dirt is encountered. But, blue rock (Basalt) required many to be blasted. Sometimes cinder was found under the blue rock, in which case the water flowed out easily. Others have to rely on fractured rock to allow any seepage at all. Another place to look at Cesspools is Maui Meadows. Most Cesspools there are only 10’-12’ deep, resulting in a very small capacity. The prevailing thought must have been that beneath the blue rock that was blasted out is a cinder layer, which is capable of absorbing a lot of flow. Driving on Piilani Highway in the cut below Maui Meadows, the rock and cinder layers are evident. I hope you enjoy our frequently asked questions. Please call me at 242-5692 and ask if you don’t see your question answered. -Dom

FAQ’S About Cesspools

Look at your water bill. Are you consuming more water? There may be a plumbing leak. Are there more people living at the house? Is there more rain? Has preventive maintenance been done?

As often as a septic tank. Please click to see the accompanying Penn State Chart. Pump more often if you have a garbage disposal.

No, there is no benefit though the rumor persists.

There may be a benefit to those in colder climates or if you have a kennel, or commercial kitchen. On Maui, the temperature is ideal for naturally occurring bacteria to do all that is needed.

If you don’t know, call us to help locate it.

Typically, unless the cesspool is in brackish water, caustic soda will help. This is industrial strength “Draino”. The dose is 100 pounds per 2,000 gallons so the usual dose is 200 pounds. You will have to pump out the sludge first. You want the caustic to open up the walls and floor of the cesspool so seepage will occur again. If the sludge in the cesspool absorbs all the caustic, there is no active chemical to work on the walls. Grease and soap scum from washing pots and pans floats on the surface and coats the walls. The grease acts like a ceramic cup and holds the water. The caustic helps break down the grease. Caustic decreases in efficiency when used more than once every two years.

The sulphuric acid that is typically used is very concentrated and dangerous to use. It is bad for the environment and, at 30 gallons or so a dose, it is not cheap. Acid may work where caustic has been applied and lost it’s effectiveness.

Judging from the calls we receive, 10-12 years seems to be the average before they start giving trouble. With the right soil conditions and proper maintenance, they can last forever.

Again, all of them are different. Sizes, perk rates, annual rain fall all varies. But, in general, anything over six people on one cesspool is likely to create problems.

Please! I recommend using this water. There does not seem to be a Department of Health (DOH) concern so long as the water stays within your property.

VIP has an aerobic wastewater treatment plant for homes that uses subsurface irrigation. For many people in arid areas, or during water moratoriums, this may add 600 or more gallons per day for landscaping.

Know where your cesspool is, inspect semi-annually, and limit water usage.

Individuals each use 100-200 gallons of water per day. If four people live in the house and four hundred gallons go in the cesspool per day, and assuming there is no drainage, it would only take eight days (400 X 8= 3,200) to replace the water our 3,200 gallon tanker removes. Again, chemical treatment is called for to increase seepage rate. Look for plumbing leaks.

OK, OK already. It’s (a) Under the bedroom you added two years ago. (b) Under your new concrete driveway. (c) Under the wood porch you built. (d) Under the pool deck. (e) Beneath the floor in the garage. (f) Below the floor under the kitchen sink. (g) All of the above. We have found them everywhere. Call us to assist you with locating camera if you have difficulty finding it.

40% toilet, 15% laundry, 30% bathing, 10% kitchen, and 5% miscellaneous. It is easy to see how a low flow toilet, low flow shower head, and diversion of laundry water will help save the sewer system. Faulty leaking toilets are the leading cause of cesspool and septic failure.

NO! If the grass is green it means the cesspool is full and the water is seeping out under the cover. Remember, the cover is supported only by dirt. The dirt will erode away, and the cover will fall in. Since it is illegal to build a new cesspool, a new septic will have to replace it. A septic is different because the design intends that some water is lost via evaporation.

Stand back from the house and look at the terrain. The cesspool should not be in a low spot or a “bowl”. A bowl will collect surface runoff water and the cesspool will absorb it. Also, look at the gutters on the house, and the roof line. Does the roof shed water in the cesspool area? Route guttering so the water goes on the opposite side of the house, or install drain pipes to carry it off.

The DOH defines a failed cesspool as one that has to be pumped more than twice a year, overflows, causes odors, or creates a nuisance. If “it” is up to your TV set, you’ve got a problem.

Yes, but the county pumps only water. If the sludge is not removed it will continue to plug the walls and floor causing poor seepage. And, if the sludge is left in the cesspool it will get thicker and thicker until there is permanent damage to the cesspool. Private pumpers charge less than the county.

Bad idea. We can’t see what we are doing unless there is the standard 16″-18″ (or greater) hole to gain access. The suction hose, when put in a pipe, will go to one spot under the pipe. How about the rest of the sludge around the perimeter of the cesspool? Also, we use “paddles” to direct sludge (turd herding) to the hose and scrape the walls. The paddles can’t get into the pipe and even if they could, we can’t see through the small opening.

It is possible sometimes, but impossible to do a good job. Only a very small hose will fit inside a cleanout and little or no sludge will be removed.

We have a camera with an electronic transmitter and receiver. This is used to follow plumbing to your system.

Yes we do. Unless you have repeat line plugging problems or suspected roots you probably would not benefit from this technology. It is not a good tool to inspect cesspool walls and structure. Inspections are best performed with powerful spotlights and mirrors.

I always blame the toilets. A toilet may leak intermittently so it is not always obvious. Put food coloring in the tank on the back of the toilet. Wait a half hour. If the color shows up in the bowl without flushing, you have a leak. Think about it. There are 1,440 minutes a day. If a toilet leaked a gallon a minute, a cesspool would fill up in 2-3 days. Even a cup a minute yields 90 gallons a day, which will fill a cesspool in 40 days or so.

I like the 1.6 gal/flush Toto available at Hawaii Pacific Plumbing. Unlike some low flow toilets, this one will do the job with only one flush.

Most cesspools and septics are not capable of absorbing the additional flow softening units contribute. There is debate that the salt used also creates less than ideal conditions for bacteria and may even accelerate damage to concrete structures. I would not use a softener on my home, unless the backwash went somewhere else. To a lesser extent the same applies with reverse osmosis drinking water systems.

Limit the amount of people using the system. If that’s not possible, limit the water going in. Use 1.6 gallon toilets and low flow shower heads. Divert laundry water. Fix any leaks. Pump out the sludge and dose with caustic. All of this can be done for much less money than a new septic system costs.

There is a long list, but if it won’t biodegrade, don’t put it in. Plastics, paint, coffee grounds, egg shells, floss, disposable diapers, condoms, tampons, cooking oil, motor oil, bleach, and solvents should go somewhere else. Please don’t empty your pool or spa here!