In 2010, the Center for the Management, Utilization and Protection of Water Resources and the Tennessee Department of Environment and Conservation (TDEC) distributed the fifth annual survey of Tennessee wastewater treatment utilities (only those that are legally allowed to handle 0.1 million of gallons or more of water per day [mgd]) to find out which ones were using water conservation and water reuse practices. A survey like this is important to Tennessee as it faces strong pressures on its water resources from human use, and the 2010 results are below.
You may also view the results from the Tennessee Department of Environment and Conservation's Web site at http://tn.gov/environment/wpc/stormh2o/MS4.shtml. The wastewater reuse survey is found in the "Helpful Links" box in the bottom right corner.
After having the opportunity to see the wastewater treatment plant and visit the land irrigated by its water, I find it amazing that more communities are not like Loretto. Nestled in the flat farmlands of western Tennessee, Loretto--with a population 1,700--is home to old fashioned architecture, country living, and one of the cleanest WWTP's I've ever seen. And it's one of only three in the state, that we know of through responses gleaned from our annual survey, that is practicing wastewater reuse. The Loretto WWTP sends reused water to the Glen Rock Golf Course and Banquet Center to use in their irrigation systems. The Golf Course paid a portion of transporting the reused water to the site , but since it was so close to the WWTP, it was easy to run the lines that the course would need to use to irrigate. This reused water comes at a lower cost than could be found through other water sources.
"We sample for the golf course three times a week for flow, E. coli, and nitrates-nitrites, which is more strict than for other uses," said Lisa Porter, WWTP operator. "Sampling for nitrate-nitrites characterizes the nutrient loading to the golf course. Nutrient loading and flow rates are the two items of concern for effluent used in golf course irrigation.
"For creek dispersal, we only have to check E. coli once a week."
The golf course has 225 acres available with 55 acres currently being utilized for spray irrigation. In Tennessee, the acceptable application rate is 0.2 gallons per day per sq. ft. The current spray irrigation acres of 55 acres could receive 0.489 mgd based on the below estimation. This estimate exceeds the plant design capacity of 0.225 mgd; therefore, this application rate based on flow is acceptable, according to Porter.
55 acres x 43,560 sq. ft./1 acre x 0.2 gallons/square x 1 mgd/1,000,000 = 0.489
The Loretto WWTP is a three-celled, partial mixed lagoon system that went online in 1993. The dimension of each cell is 138 x 414 ft with a depth of 10 ft, giving each cell a volume of 3,124,500 gallons. Each pond has two floating surface aerators. A settling pond follows the three-celled lagoon system and allows two-days' detention time.
The Loretto WWTP began reusing in 2001, according to Keith Smith, city manager. With a permitted capacity of 0.225 mgd per day, the Loretto WWTP has an average flow of 0.200 mgd. It treats 0.125 mgd for reuse.
Smith says that the benefits of reuse come in that the water is not going to the creek, and there are fewer water quality parameters to be tested. With creek dispersal, there are approximately 10 parameters to be tested.
"Public awareness about reuse is lacking," Porter said. "There seems to be a fear that reclaimed water is not clean when, in reality, there is a tighter limit on cleanliness in reuse practices. For the golf course application, only 23 colonies are allowed per 100 milliliters of water whereas normally, 126 colonies are allowed per that amount of water.
According to Smith, people don't realize the benefits of reusing. "Not only does reusing help during times of drought, but reused water is also cheaper, so the benefit comes directly to the customer."
Images from the Loretto WWTP
Images from the Glen Rock Golf Course and Banquet Center
This table shows the number of facilities that reuse water in each TDEC Environmental Field Office District. It also shows how the treated wastewater was used within each district (how many golf courses, schools and parks were irrigated with it, etc.). Note: None of the facilities used the treated wastewater for edible crop irrigation, groundwater recharge or indirect applications.
TDEC Environ. Field Office
No. of Reuse Systems
Area of Residences Irrigated
Area of Golf Courses Irrigated
No. of Parks Irrigated
No. of Schools Irrigated
Area of Other Public Access Irrigated
Area of Grass, Pasture, Other Crops Irrigated
|Nashville||1||100 acres||221 acres||3||1||64 acres||600 acres|
|2010 Total||4||100 acres||430 acres||3||1||64 acres||600 acres|
The following table summarizes the way reuse water was used among the systems that practiced the technique. It also includes the number of reuse systems, flow and area for each reuse type. The facilities did not report their capacities in this section.
|Reuse Type||Number of Systems||Flow (mgd)||Area Acres|
|Public Access Areas & Landscape Irrigation|
|Golf Course Irrigation||3||1.53||430|
|Other Public Access Areas||1||1.53||64|
|Groundwater Recharge & Indirect Potable
(See definition below)
|Rapid Infiltration Basins||0|
|Adsorption Fields (See definition below)||0|
|Surface Water Augmentation||0|
|At Treatment Plant||0|
|At Other Facilities||0|
a drainfield, including the application/distribution system, intended for the reuse of reclaimed water.
Indirect Potable Reuse
for these purposes, the planned discharge of reclaimed water to surface waters to augment the supply of water available
for drinking and other uses.
Contact information for the systems that practice water reuse is below.
|Reuse System Name||
King's Creek Golf Course
893 Mahlon Moore Rd., Spring Hill, TN 37174
Town of Jonesborough
123 Boone St., Jonesborough, TN 37659
Loretto Golf Course-Clax Branch Golf & C.C.
|Lawrence||Lisa Porter||415 South Military, Loretto, TN 38469|
|Murfreesboro Water and Sewer Repurified Water System||Rutherford||Joe Kirchner||300 NW Broad St., P.O. Box 1497, Murfreesboro, TN 37133|