Council hears ideas on wastewater disposal

Contributed photo
Marble Falls Assistant City Manager Caleb Kraenzel tells council about four options for future wastewater service expansions in a workshop on Tuesday evening.

By Alexandria Randolph

The Highlander

Marble Falls officials examined the future of the city’s waste on Tuesday by identifying four options ways the city might eliminate the eliminations.

With the city reaching a high percentage of the existing wastewater system’s capacity, Mayor John Packer called wastewater and what to do with it “probably one of our more serious issues in the next five years.”

Currently, the city has 2,645 wastewater customers, said Assistant City Manager Caleb Kraenzel. Of those, 2,044 are residential and 601 are commercial. The city has 68 miles of wastewater line, some of which is over 100 years old, he said.

“Our current plant is at 76.9 percent capacity as of February 2018,” Kraenzel said. “Texas Commission on Environmental Quality mandates when you hit 75 percent, planning must begin, and at 90 percent, construction must have begun.”

The city is producing 1.65 million gallons of wastewater per day.

The council discussed the idea of constructing a new plant on the south side of the Lake Marble Falls bridge, but Kraenzel noted that only 160,000 gallons – 10 percent of total capacity – was produced on that side of the city. Waste from the south side is transported under the bridge to the existing wastewater plant by a pipeline 12 inches in diameter.

Even with the growth of 100 new homes each year on that side of the river in communities such as Gregg Ranch and the Roper development, that number would only increase by 265,000 gallons annually by current residential averages.

“That’s not enough to sustain the operation of a traditional wastewater plant,” Kraenzel said. “The pressure right now is really on the north side plant.”

If the city expanded the existing plant, council would need to determine by what capacity; 500,000 gallons, or 1 million?

“It would mean a difference of $2.5 million compared to $4 million,” said City Manager Mike Hodge.

Kraenzel told council the city has four viable options to manage its effluent; expansion of the existing plant, obtaining more irrigation land, discharge into streams, water reclamation or a combination of those options.

Land application

The city currently uses filtered wastewater, or graywater, to irrigate 278 acres of land, including the Meadowlakes Golf Course and a part of the Cold Spring Granite quarry property on Farm to Market Road 2147.

The advantages of finding more land to disperse graywater for irrigation would be “the easiest and most economical to permit, and with TCEQ, that’s important,” Kraenzel said.

It would require no change to existing infrastructure, would require the lowest amount of maintenance and would allow for the land to be simultaneously used for crops.

The disadvantage, Kraenzel said, would be the cost of land acquisition, the matter of tying up acres of viable real estate and the increasing difficulty in finding parcels of land to irrigate.

“That’s why most municipalities build golf courses,” said councilman Dave Rhodes.

Discharge

The second option would be to discharge the graywater into a nearby creek, which would require the water be filtered extensively to meet TCEQ standards, Kraenzel said.

“Burnet had to add $1 million of infrastructure to their plant to clean it up this much,” he said.

Additionally, TCEQ regulations state that the discharge can only be made outside of 10 stream miles from the body of a lake. In the case of Marble Falls, this would mean discharging in Flatrock Creek south of the city at or beyond the border of Blanco County, or in Hamilton Creek 10 miles north of Lake Marble Falls.

“It’s a possibility,” Kraenzel said. “Many municipalities don’t have this option.”

Discharging would mean a lower cost to add plant capacity and possibly the creation of a constant flow of water in area creeks, encouraging ecosystems. It would also reduce the need for wastewater storage.

The downside?

“This is bar none the most difficult to permit,” Kraenzel said.

It would also require the construction of a minimum of 10 miles of pipeline to the discharge point and attaining the property easements for the pipeline. There is also a concern about the negative environmental perceptions of discharging wastewater, the council said.

Water reclamation

The last option Kraenzel described as “the most expensive and controversial.”

Water reclamation would allow 100 percent of wastewater to be filtered and returned back into the system as potable water.

“Cities are doing this all over the world and all over Texas, and it should at least be a part of the conversation,” Kraenzel said.

“This is a question of short term versus long term,” Rhodes said. “You pay up front for this (option).”

With all wastewater filtered and returned to the system, the city would dramatically reduce its dependence on raw water, Kraenzel said.

However, the costs up front to add the required filtering mechanisms to the existing wastewater system would be great. Water reclamation is also challenging to permit and maintain, and there is the issue of public perception, he added.

Regardless of which option was chosen, the city must prepare for a large expenditure, Rhodes said.

“Long term, we need to be looking at $15 million to $20 million,” he said.

“We only have a five-year plan with Cold Spring Granite,” Kraenzel said. “It’s prudent to have in the plan the cost of buying irrigation land.”

Rhodes agreed.

“Five years goes fast,” he said.

Councilwoman Megan Klaeger asked how the council’s preference expressed on Tuesday night would affect the city staff’s report on the four options.

Kraenzel said that if council expressed disinterest in a particular option, “we would drop that into the background.”

“The cost might be something we don’t want to hear, but it could end up being the best option,” Klaeger said. “Right now, we don’t know what we don’t know.”

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