Engineering consulting firm to work with City of Sarasota staff on steps to improve quality of city’s drinking water

City Commission approves $1.5-million contract with Hazen

This is the City of Sarasota’s Water Treatment Facility on 12th Street. Image from Google Maps

In unanimously approving a Feb. 16 Consent Agenda with routine business items, the Sarasota City Commission this week agreed to a $1.5-million contract to launch an effort to improve the taste and odor and odor of the city’s drinking water and to ensure that the water will continue to comply with national standards.

“The City regularly gets taste and odor complaints,” the city’s Scope of Services for the project pointed out.

Almost exactly two years ago, shortly after he was hired as the city’s new Utilities Department director, Bill Riebe told the commissioners, “There has been chronic taste and odor [problems with the city water]. … As a new person to the community,” he added, he had found those issues “readily noticeable, so I think it’s something to be addressed.”

“As part of the world-class vision for the community,” Riebe said, “I think it’s important to have really good potable drinking water. It really reflects well on the community.”

Additionally, materials provided to the commissioners in advance of the Feb. 16 meeting said that non-compliance problems already have arisen during periods of high demand; more are expected in the future as the city’s population grows. Without appropriate action, a city staff memo noted, periods of noncompliance “will only become longer and more intense” within the next four to five years.

Hazen, which has offices in Tampa and Sarasota — along with many other cities across the country — will serve as the consultant providing engineering services for the project, the staff memo said. It was the only firm to submit a proposal, the memo pointed out.

This is a section of the Hazen website that discusses drinking water issues. Image from the website

“Fortunately,” the memo said, the company has in-depth knowledge “of the City’s water treatment facility and processes and has provided excellent service to the Utilities Department for many years. This knowledge and expertise is expected to benefit the City through efficiencies and lower costs.”

The city owns and operates a water treatment facility that handles 12 million gallons per day, the memo explained. Located at 1850 12th St., the plant provides drinking water to both residents and businesses within the city, the memo added, with the current daily demand averaging about 6.5 million gallons. On peak demand days, the memo noted, the figure rises to approximately 8.4 million gallons.

An aerial map shows the general area of the Verna wellfields, north of Fruitville Road in the eastern part of the county. Image from Google maps

The source of the water is two wellfields — one located off Verna Road, in the eastern portion of the county; the other, located in downtown Sarasota, the memo noted. The downtown wellfield draws water from the Florida Aquifer, according to materials in the Feb. 16 agenda packet.

The water from the Verna site, the memo explained, “has high levels of hardness (calcium), sulfate, total dissolved solids (TDS) and total organic carbon (TOC).”

The ion exchange treatment process the city uses “effectively softens the water (removes hardness),” the memo noted. However, it does not remove sulfate, TDS or TOC. Moreover, the memo explained, when total organic carbon is mixed with chlorine, which is required for disinfection purposes, that can lead to the creation of carcinogens, which are “generally referred to as disinfection byproducts.”

The memo pointed out, “Concentrations of all these compounds are regulated by the Primary and Secondary Drinking Water Standards set by the United States Environmental Protection Agency …”

The source water from the downtown wellfield “has extremely high levels of chlorides, sulfate, and TDS,” the memo continued. “The existing reverse osmosis treatment process effectively removes these constituents.”
Treated water from the downtown source is blended with partially treated water from the Verna wellfield before the water is disinfected, the memo said.

“Although the City’s drinking water complies with all current drinking water standards,” the memo noted, “compliance during peak demand periods is difficult due to the increased use of groundwater from the Verna wellfield.”

Typically, the memo said, it takes from four to six years to evaluate, design, permit and construct drinking water improvements. The engineering contract the City Commission approved on Feb. 16 will enable Hazen to provide “the necessary engineering services” for the evaluation and design of the improvements, the memo added.

The project has been planned in four phases, the memo continued. City staff will review the findings and recommendations at each stage, the memo said, before the next phase can begin. “Staff will strive to minimize [the] costs as much as possible,” the memo added.

The “overarching goal,” the memo pointed out, is to provide “the best value to the City’s customers.”

This is a chart provided in the materials about the Hazen contract. Image courtesy City of Sarasota

The memo also noted that staff expects the total cost of constructing the improvements will be about $8.1 million. The adopted budget for the project, the memo said, is $9,688,000.

The Scope of Services noted that the project “may have multiple funding sources …” Among them could be loans from a state fund; money provided through the Federal Water Infrastructure Finance and Innovation Act; Southwest Florida Water Management District grants; Florida Legislature grants; and bonds.

“It is anticipated that all necessary improvements will be constructed at the City’s Water Treatment Plant site,” the Scope of Services said.