If your land is connected (or can be connected) to public water and sewer, you don’t have to worry about this. All you have to do is to get a quote from the public utilities to connect  your land to public water and sewer. But if the land cannot be serviced by public water and sewer, you will need to have a well dug and a septic system installed on site.

For a well to be dug, there are typically very few restrictions other than the mandated separation between the septic leach field and the well. You don’t want the waste from the septic system to seep into your well water. A septic system on the other hand cannot be installed unless the land passes a perc test.  If the land already has a well; you need to obtain results of the flow testing done on it. The county will get the water tested before you connect the well to the plumbing in the house. If you are getting the well dug yourself, do not try to cut costs and stop drilling as soon as you hit water with the desired flow rate. Water tables can vary and you are better off drilling a bit deeper than required so that you have a safety margin. Note that the cost to drill, case and cap including the mortar required for the well are only half the costs. You then have to install a pump, piping, a pressure tank and possibly a water filtration system before the well can be used.

Now let’s get back to septic. If the land fails perc tests, the lot cannot support a septic system. If it cannot support a septic system, it is a non-buildable lot.  If on the other hand the land has passed the perc test, the actual results of a perc test determine the size of the septic system that the land can support. This in turn determines how many bedrooms the house can have. The test results should state this and mark the area on the land where the septic system can be installed. The system cannot be installed on steep slopes .  It cannot be too close to the wells on neighboring properties. The well on your land also cannot be too close to existing septic systems on neighboring properties nor can it be downhill from a nearby septic system.  These slope and setback constraints might result in a land without space for a leach field or well even if it passes the perc test. Also note that in certain counties, perc tests have a shelf life. The MLS listing for a land could indicate that the land has a perc on file. But if it has expired or will expire within months of your purchase, you will have to perc the land again. Note that soil conditions change, water tables change, new neighboring developments might make it more difficult to maintain the setbacks required by septic systems on your land or the criteria for passing a septic test itself could become more stringent. So a successful perc in the past does not guarantee a successful perc few years down the line.

If the land passes perc, depending on the land conditions, the land will get approved by the health department for septic installation; but with a stipulation on the type of system.  The ideal condition is to be approved for a conventional septic. Be careful if the perc results call for a sand mount system. This essentially involves hauling sand to the land to build a leach field – a much more expensive proposition. If the land needs to be perc tested and you are willing to take up the hassle expect it to be a time consuming process.  Note that many counties like to run septic tests during the early winter months of the year when the water table is high. Applications to run the perc test have to be submitted before that time period and depending on their work load, you could be waiting weeks or months for the test to be conducted.

Once a septic system is installed there are restrictions on its use – you cannot build within a certain feet of wells and septic leach fields. You cannot drive heavy machinery and cars over the leach field or the septic tank. Nor can you grow trees or plants where the root system can penetrate the leach field. Keep all this in mind when you plan the location of your house and any access to the construction lot.

If all this isn’t complex enough, Maryland and possibly other states have started requiring installation of an additional module called BAT (Best available technology); thus increasing the complexity and the price of the system. The additional cost of installing a BAT system ranges from $14,000 – $18,000. This is additional cost on top of the cost incurred in installing the septic tank and leach field! To understand BAT, you need to understand how a septic system works.

In a conventional septic system, all the black water (toilet waste) and gray water (kitchen, shower, laundry) are mixed together and piped into the septic tank. Here, the waste is allowed to settle. Bulk of the solid waste (typically poop) settles to the bottom of the tank. The liquid waste and scum from the top is then directed using perforated tubes over to a leach field. Here the liquid waste is dissipated and goes through layers of rock/gravel/sand which act as  a filtration system before being released into the surrounding land. Studies have shown that this filtration process is not sufficient and the liquid is not ‘clean’ enough to be entering the surrounding water table. Not everyone agrees with this opinion or for that matter even the parameters being measured to determine if the water is ‘clean’. But this blog entry is not about my or anybody else’s opinion. I am just stating what you are required to do as per state laws.  So the state health department has mandated that the liquid waste from the septic tank needs to be ‘treated’ before being sent out to the leach field. The BAT system is a handful of technologies that are approved by the health department for this ‘treatment’. When you hire a contractor to install your BAT system, you need to ensure that they are county approved to do this work. A county health inspector also needs to be present when the system is being installed.

Are you allowed to install a composting toilet? Yes and No. Yes; but only as a backup system. Not as a primary system.

Chances are, even if they let you install it as the primary system; it comes contingent on the fact that your house is plumbed up to support a conventional system if the composting system fails. Also, you have to install the BAT system with the composting system. There is work being done to get some of the big name composting systems to be approved as BAT systems themselves; but that’s not happening in the near future. This is a subject worth another blog entry……………..it deserves one.

The current system of mixing relatively small amounts of toilet waste (black water) to large amounts of gray water waste; thus creating a really large pool of black water waste is simply stupid. Unfortunately, gray water systems are not permitted in Maryland. Hopefully things will improve over time and we want to be prepared for it. So we are planning on designing our plumbing system such that we can separate the gray water and black water easily.  It is as simple as having 2 feeds into the septic tank or even combining the 2 feeds just before it feeds into the septic tank. This way we can isolate the gray water plumbing any time we want to in the future.