Tag: Environmental Engineering

3 Steps to Consider when Facing Challenges with Water Supply in Florida

Photo of a well in Florida with words overlayed saying "Water Supply Development Challenges"

One of the societal changes that has taken place because of the pandemic is working remotely, which has allowed people to live anywhere and not be tied down to an office. In Florida, this has resulted in an enormous, unplanned and unexpected real estate boom that has stressed a critical public infrastructure: the water supply.

Pre-pandemic, in January 2020, a study for a city in central Florida projected no need for increasing its permitted supply until 2045. A year and a half later in May 2021, our updated projection found that the amount of newly proposed development accelerated that need to 2027, almost 20 years sooner.

With the real estate boom and pressure on a public water supply, the risk would be running out of water. So, there are some considerations to be made before a municipality can determine next steps.

  1. The first step is to consider its water withdrawal permit. In Florida, these permits are issued by the five water management districts. Like comparable regulatory agencies throughout the US, withdrawal permitting is often complex, challenging and – at times – contentious, given that high quality water is a limited resource subject to competing needs and interests.
  2. Second, consider alternative water supplies. This may include sources like deeper aquifers or saline surface water that has not been considered in the past because of greater treatment requirements and higher capital and operating costs.
  3. Third, focus on water conservation to reduce per capita water consumption as well as increased beneficial reuse of treated wastewater (for example, lawn and golf course irrigation).

The need for additional water supply is, of course, not limited to Florida utilities. In Swansea, Massachusetts, the ground water option was tapped out. The water district was getting as much out of wells as it was going to get and regional alternatives for water didn’t make sense, economically. There, a new supply based on taking water from a coastal tidal river was developed that included treating a wellfield with high iron, manganese and carbon dioxide. After aerating the wellfield, an ultrafiltration membrane system provided iron and manganese removal for the wellfield as well as solids removal pretreatment for the river water. A reverse osmosis (RO) treatment system then desalted the river water. The treated well water helped to stabilize the desalted river water without the need for carbonate addition. Desalting will likely be required for the Florida alternative supply project.

The Floridan aquifer that our Florida client utilizes is one of the largest in the country lying beneath the entire state of Florida and southern portions of South Carolina, Alabama and Georgia. It varies in depth and lithology, and the high-quality zones can be stressed by overpumping, leading to the use of less desirable strata both from water quality and greater depth standpoints.

Our engineers have been aiding municipalities and counties with the challenges they face in their drinking water and wastewater supplies and treatments for decades. Do you have questions or concerns about issues your community may be facing? Please contact me!

PFAS Contamination in New Hampshire Drinking Water: What Our Water Quality Experts are Learning about this Emerging Contaminant

picture of a faucet in someone's kitchen pouring water into a sink to show drinking water contaminants

The whatTeal circle with "NH PFAS Sources" written on top and inside circle, text explaining where PFAS contaminants originate in NH

Perfluoroalkyl compounds (PFAS) are manmade chemicals that are characterized by very stable carbon chains that allow them to act as a strong repellent to oil, water, and stains from other liquids. These desirable properties mean they are found in hundreds of consumer products as well as in firefighting foams.

There are more than 1,000 forms of PFAS compounds that have different chemical makeups and properties and different levels of toxicity. To date, the most commonly found PFAS compounds are ‘perfluorooctanoic acid’ (PFOA) and ‘perfluorooctanesulfonic acid’ (PFOS).

These forms have long carbon chains, do not readily break down in the environment, are water soluble, and have been found in some New Hampshire groundwater supplies at elevated levels.

The why

The public health concern is for PFAS to be consumed, absorbed and accumulated in the body at toxic levels. Although more research is needed, initial scientific studies indicate that long-chain compounds like PFOA and PFOS may cause developmental effects in infants, interfere with the body’s natural hormones, increase cholesterol levels, affect the immune system and increase the risk of cancer. Scientists are still learning about the health effects of PFAS and their toxicity, though it is believed that the PFAS compounds having shorter carbon chains are potentially less toxic since they remain in the bloodstream for shorter periods of time.

Are these compounds in your public water supply?

The who

In 2017, EPA recommended PFAS levels they believed would not lead to toxicity while allowing states to consider more stringent levels for compounds of concern. The NH Department of Environmental Services (DES) has been working diligently on amendments to their drinking water rules to protect public health and the environment from PFAS in our drinking water. New rules were recently adopted that will affect every public water system in the State of New Hampshire.

The when

Last week, Hoyle, Tanner’s water quality experts attended the NH Drinking Water Exposition and Tradeshow learning about New Hampshire’s new PFAS limits. DES submitted amended public drinking water rules in July 2019 to the state legislature which voted in favor of the new standards. The new standards became effective on September 29, 2019 setting  the Maximum Contaminant Levels (MCL) in public drinking water for specific PFAS compounds as follows:

  1. PFHxS = 18 ppt
  2. PFNA = 11 ppt
  3. PFOS = 15 ppt
  4. PFOA = 12 ppt

The new rules require public water supplies to begin sampling and reporting levels of these four PFAS compounds beginning in the fourth quarter of 2019 (Oct-Dec) with continued quarterly sampling and reporting in 2020 and beyond. The regulatory thresholds will be based on a 4-quarter running average for each of the PFAS compounds with compliance indicated by a 4-quarter average that is less than the MCL for each compound.

By January 2020, DES will be submitting draft rules on PFAS in surface water to the New Hampshire legislature – more to come on this front!

The how

Proper sampling is critical to avoid contaminating samples. Many communities are not equipped to perform the sampling themselves and will rely on certified laboratories for proper sampling, analytical methods, and meeting the quarterly sampling and reporting schedule.

The DES Water Quality Experts

Hoyle, Tanner’s water quality engineers are committed to keeping at the forefront of emerging regulations and technologies to be able to better serve the communities where we live and work.  You may contact me, Joe Ducharme, Regional Manager of Environmental Services, at 603-669-5555, x-142 or email me with any questions or water quality needs – we are here to help!