Sites and soils

“The State of Vermont adopted, on July 1, 2007, universal jurisdiction over the design, permitting, and installation of all new wastewater systems and potable water supplies. All new wastewater systems and potable water supplies need to obtain a Wastewater System and Potable Water Supply Permit for activities such as: subdivision of land; construction of a new building (including single family residences) that need a wastewater system (often referred to as sewage disposal or a septic system) or water supply; and repair and/or replacement of a failed wastewater system or water supply. A permit is also required when there is an existing wastewater system and/or potable water supply but there will be an increase in water or wastewater design flows due to either a modification to, or a change in use of, a connected building.” ( https://dec.vermont.gov/water/programs/ww-systems/permit-compliance )

So what does this mean in practical terms for Windham? Let’s take a look at where Windham’s houses are now and what soil they are sited on. To do that I downloaded the soils attribute data and documentation from the Vermont Geodata portal. The documentation explains the suitability of each of the soils for domestic wastewater using a rating system of I through V from most suitable to unsuitable. Of course there’s categories within the 5 groups and those are shown in the image below in graduated shades of gray beginning with light gray for most suitable. Only those soils in the suitable and marginally suited categories is shown in the image below.

Using the VT 911 database to position building in Windham on those selected soils and color coding those dark green on the most suitable soils to light green on lesser suited soils we have a better picture of where and what.

Suitable soils and the houses sited thereupon

Assuming that most Windham houses were built before 2007 it is pretty clear from the image that people were choosing the most suitable sites before the state imposed their rating system with 78% (368 of 472) of Windham’s houses sited on suitable soils. Armed with this realization it is difficult to assert that rule-making by the state placed un-necessary constraints on home building in Windham.

But our data does show that most of the “good” sites are already taken and future building may need a more costly septic system and/or longer driveways which are costly to build and maintain.