HomeMy WebLinkAbout1.03 ISTSISTS MANAGEMENT PLAN
WATER AND SEWER REPORT
T.O. RANCH
WATER
The T.O. Ranch will be served by individual water wells. The individual water demand of the
subdivision will be typical of a single- family residential community. Each single - family lot
can be expected to demand approximately 420 gallonslday based on a 3.5 persons /residence
occupancy rate. With the addition of an accessory dwelling the demand will increase
approximately 300 gallons/day based on 2.5 persons /ADU. The total demand for a lot with an
ADU would be approximately 720 gallons/day. Individual lot owners will be responsible for
well drilling, water treatment and maintenance.
SEWER
The T.O. Ranch will be served by Individual Sewage Disposal Systems (ISDS). The sewage
generated by the subdivision will be typical of a single- family residential community. Each
single- family lot can be expected to generate approximately 350 gallons/day based on a 3.5
persons /residence occupancy rate. For lots with an accessory dwelling unit the sewage
generated would increase to 600 gallons/day, based on 2.5 persons /ADU. Individual Iot
owners will be responsible for the installation of an engineered ISDS. Maintenance of each
system will be the responsibility of the individual lot owner and as outlined in the protective
covenants of the subdivision.
SEWAGE REQUIREMENTS FOR T.O. RANCH
Due to recent concerns in Garfield County regarding traditional Individual
Sewage Disposal Systems (ISDS) and the potential for these systems to reduce the
quality of surface and shallow ground water, High Country Engineering proposes that
all three lots be required to provide Secondary Treatment of their wastewater, through
an Individual Sewage Treatment System (ISTS). An ISTS treats wastewater
aerobically, maximizing the oxygen level in the system to enhance bacterial growth.
The abundance of bacteria then digest the wastewater and break down the harmful
pollutants.
There are many different types of aerobic systems available on the market today
and each system employs a unique method of treatment. Aerobic treatment systems use
technology such as Sequencing Batch Reactors, Activated Sludge, and Trickling filters
or a combination of these processes to achieve the desired quality of discharged water
or effluent. Most systems have options for further treatment such as denitrification,
disinfection, and even treatment up to drinking water standards in the extreme case.
Since aerobic systems require oxygen as an essential part of treatment, they use
mechanical pumps, compressors, motors and electronics to maintain ideal conditions for
bacterial growth. Because of the mechanical components, these systems are more
expensive to purchase, install and maintain. Therefore, all of the systems installed on
TO Ranch will be required to have bi- annual tests and routine maintenance to insure
that each system functions properly. These systems can even be designed with a remote
warning system so that if there is a problem, a technician will be notified and the
problem can be fixed immediately.
The Colorado Department of Health (CDOH) has approved various systems that
meet the NSF International Standard 401 (ANSI /NSF 40 -1999) for Residential
Wastewater Treatment Systems. Although some of these systems treat water to a
quality that could be released safely into surface water drainages, the CDOH does not
allow this type of discharge. CDOH requires that these systems discharge into an
absorption field similar to a traditional ISDS. This type of release will further treat the
effluent before being returned to the environment.
In summary, T.O. Ranch will require as a minimum:
• An engineered ISTS and subsurface drain field for each lot.
• All ISTS systems shall meet the minimum requirements of ANSI /NSF 40
• System sized by the engineer or manufacture adequate to treat the
wastewater produced by the lot
NSF (National Sanitation Foundation) International Standard 40 is available at:
http://www.nsf.org/publications/