The Dolores water and sewer systems are older but in good standing, according to a recent analysis by engineering firm SGM.
Areas that need improvement were identified, and savings are needed to replace aging systems and to comply with new regulations, said Louis Meyer, a civil engineer with SGM.
“The broader view is that your systems are in good shape and are well maintained,” he said. Both the water system and sewer system are at about 25 percent capacity and can handle additional growth.
“You could double in population, and the plants could handle it,” Meyer said
Water supply is strongDolores has strong water rights, good supply for growth and system redundancies. The town has a 1.3 cubic-feet-per-second water right on the Dolores River that has a very senior status under Colorado appropriation laws. The town’s rights also include two wells.
Municipal water is pumped to a 300,000-gallon tank above town. During winter months, Well No. 1 is sufficient to supply town’s domestic and commercial water demands. In the summer, the water treatment plant draws water rights from Dolores River to meet the additional demand. A second, shallower well is used for park irrigation.
“Having the well and Dolores River, plus a back up tie-in with Montezuma Water Co. provides good redundancies for Dolores,” Meyer said.
Average daily water demand between 2013 and 2017 was 139,000 gallons per day.
“Water consumption has gone down (in those five years) by fixing leaks and maintaining things well,” he said.
In 2013, average daily use was 145,271 gallons, and in 2017, average daily use was 139,737 gallons.
The domestic well and water treatment plant have a capacity of 1.1 million gallons to 1.6 million gallons per day, compared with daily maximum demand of 300,000 to 400,000 gallons.
The water distribution system is 60 years old, and older iron pipes have been replaced over the years with more flexible plastic pipes.
Other highlights from the report on the water system:
The water plant is vulnerable to debris flows caused by wildfires in the watershed. The town’s redundant system allows the town to access water from a well if the plant had to be shut down because of debris flow.Six-inch and 4-inch waterlines should be upgraded to a at least 8-inch lines to meet fire flows of 1,000 gallons per minute recommended in the International Building Code. Insurance companies track whether towns have adequate fire flows when determining rates.New standards under the Safe Drinking Water Act will require additional water treatment measures, Meyer said, but the change is relatively minor.Water pressure is low in town along the north boundary of the valley floor and east of town where the water line goes beyond the city limits.Dead-end lines should be looped to improve water pressure. An additional tank might need to be considered to accommodate potential growth to the east and solve pressure problems.Waste water plant faces new rulesThe waste-water treatment facility on the west end of town is also in good shape, but at 28 years old, it will require updating in the coming years or possible replacement, according to the report.
The lagoon and sand filter system plant is permitted to handle 470,000 gallons per day. Existing maximum per month flows are 93,000 gallons per day to 119,000 gallons per day, and the average daily flow is 60,000 gallons per day. The plant is at 20 percent to 25 percent capacity, and is meeting discharge standards.
But tighter river pollution standards from the Colorado Department of Health and Environment will impact wastewater treatment systems for smaller towns in less than 10 years, Meyer said.
CDPHE Regulation 85 has strict standards for nitrogen and phosphorous discharged from waste treatment plants. Smaller plants like the one in Dolores used to be exempt, but Meyer said a new directive will require them to comply with the standard by 2027.
“Typically lagoons do not treat for those two things,” he said.
The current lagoon system could be retrofitted to meet the new standards, or the wastewater plant could be replaced with a mechanical system that is designed to meet the nitrogen and phosphorous standards.
A lagoon system can be upgraded to meet the standards. But a cost-benefit analysis was recommended on the two options, taking into account that the plant is 28 years old and will eventually require other upgrades for liners, diffusers and blowers.
It was estimated that a new mechanical plant wastewater treatment plant would run between $4 million and $7 million. Funding could come from EPA or DOLA grants.
“It is a big regulatory change coming down the pipe,” he said. “Aging infrastructure is a very challenging issue for small communities.”
Other highlights from the report on the waste water system are:
Camera pipe inspections revealed aging sewer collection lines that need repair or replacement in the area between 18th and 22nd streets north of Colorado Highway 145.The water tank above town needs a new interior coating in the next three to five years, according to a recent inspection. The job would take about a month and would require the tank to be drained. During the job, Dolores might need to buy water from Montezuma Water Co. to meet demand.Lagoon-style wastewater treatment plants have a 20- to 30-year lifetime. Mechanical plants have a 15- to 20-year lifetime.Total value of the domestic water supply and wastewater system came in at $10 million. To cover replacement costs as they age would mean setting aside $500,000 per year.
The concerned look by board members is typical after municipal infrastructure reports, Meyer said.
“All communities have this same issue,” he said. “Keep replacing lines a little at a time like you have been doing. The solution is to set aside more funding and consider raising rates a bit now. If you don’t, there could be a funding crisis in future.”
The analysis of the water and sewer systems was financed by a grant from the Department of Local Affairs.