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Your Site Evaluation
And The Role of Your Consultant

Why Hire a Consultant? The Health Department is Cheaper!
Your local health department's environmental health specialists don't just evaluate property for onsite wastewater treatment systems. They also inspect the local restaurants, campgrounds, hotels, motels, respond to general environmental complaints, perform investigations into animal bites, conduct education and training seminars for the general public, and perform disease surveillance. Their staffing is limited, and their time is extremely valuable.

With all their duties and responsibilities, they sometimes can't spend as much time on your property as they need to. Also, their work is prioritized, with those job responsibilities having a high impact on the public health having a higher priority than siting an onsite sewage treatment system on a vacant lot. There is not a lot of public health issues at stake, on a property where no one is living yet.

A consultant can usually spend more time on your property, and evaluate the property fully, where as the local health department personnel may have other more pressing issues to pursue and time constraints as to how long it takes to process other applications, or perform other inspections. Yes, a consultant is certainly more expensive than the local health department. The local health department may only look at one or two sites on your property. If neither of these sites meets the current Sewage Handling and Disposal Regulations, your lot may be denied. A consultant on the other hand is getting paid to find you an onsite wastewater treatment system. If that means we have to evaluate ten different sites to find suitable soils, then that is what has to be done. We aren't under the time constraints that govern the local health department.

So what is a site evaluation you ask?
To begin with it is a time to gather information for issuing an on-site wastewater treatment system permit. A landowner must have a treatment system permit to build a home unless public sewer is available. Your local health department is usually the responsible party for issuing these permits. They use the facts they collect at your site, or the information that your consultant has provided during his/her site evaluation to help determine a specific lot's ability to support an onsite wastewater treatment system.

Also, research must be done on the adjacent properties to determine where an onsite sewage treatment system may have already been permitted, and if a private water supply is involved, where it is located. All of this is time consuming, and it is a necessary part of the site evaluation.

What's in it for you?
Clean water and property protection are what's in it for you. People often ask why the Health Department looks at each building site it permits. What's all the fuss about? All the fuss is about purifying wastewater before reusing it. That's right, your waste water will be used again. Others may consume it using nearby wells or it may move into a nearby stream or river. You may even reuse it yourself. The mission is to provide you safe and sanitary wastewater treatment..

How do Consultants and the Health Department do what you do?
Your consultant, like your local environmental health specialist is trained in natural science and in most cases, are ex-health department employees. He or she evaluates how well the soil on your site can treat and dispose of sewage. You can learn a lot about your land by meeting and talking with the consultant. You may discover learning about your local soils and geology is fascinating.

Some seasons are busier than others.
Spring and fall are our busy times. Sometimes it can take us additional time to complete reviews during these seasons. This is usually because everyone thinks about building their dream home, or subdividing their property around this time. We don't like backlogs anymore than you do, so we'll do all we can to keep the process moving! In general, we can get most construction permits out in three to four weeks.

Should you go to the site evaluation?
We recommend that you be there for the evaluation, if at all possible. It is important for you to learn about your unique site conditions. By coming to the evaluation, you can often answer simple questions for the consultant, and by this prevent a return visit and permit delays. Generally, you will learn the date and time of the site visit a few days before it happens.


Here we the site evaluation.

What a view!
The consultant will want to know where you plan to put your house and driveway. He or she will also have to find out the locations of neighboring wells and onsite treatment systems, and whether they will conflict with your plans. This is part of the research and the information should be on file at your local health department

In addition the consultant will look at the landscape features of your property. Ridges, slopes, and rock outcrops are critical issues in safe wastewater treatment. A slope that sheds water instead of collecting it is an ideal location for most sewage systems, but drainageways, swales, and low landscape positions are not.

It's hole digging time!
After looking at the landscape, neighboring land uses, and your plans, the soil evaluation process can begin. The consultant will look at soils collected from at least three to five holes on your lot. These samples help the consultant describe the site. Samples show key soil colors, texture, and structure. They also show the distance between the ground surface and underlying rock layers, as well as the ground water table.

A hand auger or backhoe is most often used to dig up the soils for evaluation. The hand auger is a tool used to bore holes about 3" in diameter and up to 6 feet deep. The auger lets the user pull soil samples for examination. Backhoes dig pits large enough for a specialist to see the side wall and examine the soils.

When the site is just too hard to get soil samples...
When rock or stoniness stops the use of an auger, the consultant will ask you to contract a backhoe. Arranging and paying for the backhoe is the client's responsibility, unless otherwise stated in the estimate. Some areas of Virginia are so stoney that they always require backhoes.

What kind of soil is needed to install a sewage treatment system?
The consultant looks for well-drained soils. These soils are the final treatment stage to an onsite system, help purify wastewater and make it safe water to use again. The soil color tells the consultant if the soil is well-drained. Well-drained soils usually have bright brown colors to them. Soils containing a seasonal ground water table are not well-drained. Usually these soils have gray, yellow, red or pale brown colors. Most research shows two to four feet of well-drained soil is necessary to clean wastewater.

We're also looking for how it "percs"...and we don't mean coffee.
Your consultant will estimate how fast water will move or "perc" by feeling the soil's texture. Soils that perc too quickly can contaminate ground water. Those that perc too slowly can cause sluggish plumbing flow. This can produce sewage overflows both inside and outside your home. After estimating the perc rate, the consultant chooses a system sized to meet your needs.

Traveling down under...
The consultant also checks to see how deep the soil is on your land. Rock and compacted soils, called pans, are the most common limitations to soil depth. There must be two to four feet of well drained soil remove most bacteria and viruses from wastewater.

In Virginia we require at least 18" of well drained soil above rock or restrictive layers. If more is available we will use it. Some geologic formations, such as limestone, are especially subject to transporting contaminated water. In limestone formations, contamination can easily travel miles. The physical and chemical nature of the earth's formation determines the degree of hazard. Even a single ridge of rock can cause serious health threats if an onsite treatment system is installed too close to it.

How long does an evaluation take?
The soil and site evaluations are usually finished in two to four hours, not counting the time to research your property at the local health department. If the first site is not satisfactory we try to look at a second site. Lots with several acres can have more than two possible sites.

What if we can't find a workable site?
It happens sometimes, but not often. There is property that just won't support an onsite wastewater treatment system, no matter how you design it. If you have enough money, we can engineer a system that will clean your wastewater up enough to drink it, and discharge it direct to a stream or ditch.

Let's talk permits.
To receive a permit, a site must meet the standards found in the Sewage Handling and Disposal Regulations. After locating a suitable site, the consultant drafts the permit. This is then submitted to your local health department, along with copies of the consultant's soils reports and other documentation supporting the type of onsite wastewater treatment system we are proposing. The local health department then reviews the paperwork, may make a site visit to confirm our findings, and only then do they issue a permit.

A copy of the permit is sent to the building inspectors office and a copy is kept on file in the local health department. Once complete, the health department mails it to the applicant or holds it for the applicant to pickup.

That about wraps it up!
The need for effective sewage treatment and disposal meets each of us where we live - at home. Site evaluations and issuing sewage system permits are the first steps in a long-term commitment to homeowners and their communities. We are committed to insuring that Virginia's homes have safe wastewater treatment and dispersal systems. Using our land wisely and protecting our ground waters provide a rich inheritance for us today and for future generations.

The information on this page was taken from the VDH pamphlet, "Taking the mystery out of your site evaluation", March 1991. Minor revisions have been made to reflect changes which have occurred since the original publication. Additional copies of "Taking the mystery out of your site evaluation" are available through you local health department office or from the Division of Onsite Sewage and Water Services by calling (804) 786-1750.