Protest 1

The excerpt below is one of many formal comments made during the public hearing recently contesting NBU's permit renewal and sites numerous studies:

RE: The protest of the TPDES permit #TX0010232-001

The Preserve Lake Dunlap Association (PLDA) is protesting the amount of nutrient loading into Lake Dunlap from the New Braunfels wastewater treatment plant (NB WWTP). “Nutrient loading” usually refers to nitrogen and phosphorus entering a river or stream. Spring water in Central Texas is rich in nitrogen; therefore the Comal has a lot of natural nitrogen. When phosphorus is added to nitrogen, a perfect fertilizer is created, causing algae blooms to occur.
Eutrophication is what scientists call it when increased nutrients cause lakes or rivers to become overly productive or have an overgrowth of plants and algae. Algae is measured by the amount of chlorophyll in mg/L. Lake Dunlap is now considered “eutrophic” and reaches “hypereutrophic” levels of chlorophyll in the summer months according to recent studies.
Lake Dunlap is one of the most studied lakes on the Guadalupe River. Most of the studies done on Lake Dunlap have centered on phosphorus and its role in eutrophication. You can go to GBRA's website to find more information of the studies done on Lake Dunlap. I was shocked to find out how long it has been established that Lake Dunlap's eutrophication is the result of phosphorus released from the NB wastewater treatment plant. I would like to read a brief excerpt from some of the studies having been done on Lake Dunlap.

Hannan, Herbert H. and Willard C. Young, 1970 Physiochemical Limnology of the Guadalupe River, Texas. Texas Water Quality Board, Grant No. 373.

This study states the river is assimilating phosphorus as it travels downstream of the sewage treatment plant.” Hannan and Young deduced that sewage treatment plants were an obvious source of phosphorus. They also determined phosphorus, not nitrogen, was the most critical nutrient in addressing algae and eutrophication.

Mayhew, Joe J. 1970. Nitrogen and Phosphorus Dynamics in a 153 Kilometer Stretch of the Guadalupe River, Texas, M.S. thesis, Southwest Texas State University, San Marcos, Texas. 147 pp.

Again this study states that the primary source of phosphorus in Lake Dunlap was the New Braunfels WWTP.

Brandes, J. Robert and Howard O. Andrews, 1977. Data Report: Lake Dunlap Eutrophication Study. Texas Water quality Board No. 31990. Austin, Texas

New Braunfels (i.e. WWTP) was noted to be the most significant source of nutrients to the Lake Dunlap area. It stated that point source discharges (WWTP) account for 58% of the phosphorus inputs. Non-point sources (septic tanks, etc..) had little effect on the lake as a whole.

Guadalupe-Blanco River Authority. 1978. Final Report of a Basic Data Report Vol. 1: Guadalupe Basin Water Quality Management Plane. Gathering 1977-1978, Lake Dunlap, Comal and GuadalupeCounties, Texas., Texas Department of Water Resources.

The New Braunfels effluent (treated sewage water) phosphorus content was reported to be in excess of 2,000 times the stream concentration.

Guadalupe-Blanco River Authority, 1981. Working Paper Lake Dunlap Study. Texas Department of Water Resources.

The major problem with the water quality of Lake Dunlap was noted to be eutrophication, or excessive levels of both algae and macrophytes. Analysis of the data suggested that phosphorus was most often the limiting nutrient. One of the alternative methods to control eutrophication was reduction in phosphorus from New Braunfels WWTP.

Espey, Huston & Associates, Inc. (EH&A). 1981 Interim Report:Task 1804.312: Projected Water Quality Lake Dunlap Study. EH&A Document No. 61538. Austin, Texas.

This report analyzed alternative measures and feasibility for reduction of nutrient loads of Lake Dunlap. The results showed that point source phosphorus controls substantially affected levels of phosphorus in Lake Dunlap. Phosphorus control of just the New Braunfels STP was considered effective and that this would reduce macrophyte and algae production.

Glass Environmental Consultants. 1982. Interim Report: Lake Dunlap Study, Impacts of Alternate Control Strategies. Guadalupe-Blanco River Authority No. GO108.

The two control strategies that were considered required reduction in phosphorus discharged from the New Braunfels WWTP to either .5 mg/L or 2 mg/L. Reducing phosphorus to .5 mg/L in effluent from the NBU WWTP, would SIGNIFICANTLY reduce algal and macrophyte growth.

Wright, R.M. and A.J. McDonnell. 1986 Macrophyte Growth in Shallow Streams: Field Investigations. ASCE Env. Vol 112.

This study concluded that water concentrations of phosphorus could affect sediment concentrations, and that higher water P concentrations produced higher macrophyte growth. Wright and McDonnell also presented a model of macropyte growth, one receiving and dominated by wastewater and the other with no wastewater sources. The model indicated a reduction in macrophytes with a reduction in river water Phosphorus concentrations.

Espey, Huston & Associates, Inc. (EH&A). 1998. Analysis of Aquatic Plant and Nutrient Conditions In Lake Dunlap. Texas Clean Rivers Program No. 14215. Guadalupe-Blanco River

This study used a simulated method of study and found that reducing point source phosphorus down to .5 mg/L, which is about as low as technically achievable with tertiary treatment, would reduce the peak chlorophyll concentration as much a 60%. This study stated tertiary treatment would not be the preferred method from an economic perspective. However, where reductions in the point source nutrient load (NBU WWTP) can be made in a cost-effective manner, they are more desirable. The cost of such treatment can be expected to reduce planktonic algae levels in Lake Dunlap as well as the downstream lakes when the river flows are low to moderate. This report provides cost estimates of tertiary treatment, which is drastically different from the cost estimates NBU has been giving.

Alan Groeger, 1999-2000. Trophic Status of the Reservoirs of the Lower Guadalupe River, Particularly in Relation to Flow. Prepared in cooperation with Texas Natural Resource, Conservation Commission, U.S. Environmental Protection Agency, The Guadalupe-Blanco River Authority and Texas Parks and Wildlife.

This study focuses on the affects of nutrients, water temperature, and water flow, have on the eutrophication of a lake. This study states that phosphorus increases dramatically downstream from the NB wastewater treatment plant and that phosphorus is the limiting nutrient that causes the algae to grow. This study also verifies that flow is very important for the lake to handle amount of nutrient loading by the NB WWTP. This study states that the NB WWTP is the “culprit” and bulk contributor of phosphorus entering into Lake Dunlap.
It is not surprising that studies since the early 70's to the most recent study 30 years later all repeatedly make the following conclusions:

Phosphorus is the limiting nutrient that stimulates the growth of algae.
The increase in plants and algae, known as eutrophication, degrades water quality.
The New Braunfels wastewater treatment plants contribute the bulk of the phosphorus entering Lake Dunlap with concentrations of phosphorus increasing dramatically downstream from the WWTP.

Both the studies in 1998 and in 99-00 have stated that removing phosphorus from the WWTP would have a significant impact on the reduction of algae.

What is surprising is that NBU is still not convinced that they are the source of the phosphorus pollution and they are still not convinced that if they treated for phosphorus it would have a significant impact of the water quality of Lake Dunlap. How many more studies need to be conducted to convince NBU and TNRCC that the phosphorus leaving the NBU wastewater plants is degrading water quality?

On behalf of the members of the Preserve Lake Dunlap we request a contested case hearing on the renewal of South Kuehler wastewater plant. The degredation of water quality affects each one of us in the following ways: Quoted from Dr. Groeger's 99-00 study.

The increased phytoplankton reduce the clarity of the water, an important aesthetic value of a river or lake.
The increase in algae and or large macroscopic plants leads to a depletion of oxygen when the algae and plant material decomposes. This can have an impact on the fish and other organisms living in the water.
The phytoplankton such as algae commonly cause taste and odor problems in the water and under extreme conditions, diarrhea or allergies.