Thoughts From Engineers: Look to the Watershed to Protect Water Quality
The results of an in-depth study of groundwater released in early 2019 showed that 42 percent of private wells in southwest Wisconsin are contaminated with bacteria associated with farm operations and failing septic systems. In northeast Wisconsin, the region’s geology consists of a thin layer of topsoil over fractured limestone. Groundwater is vulnerable here, as cows outnumber people 5 to 1 in Brown County, Wis., and agriculture is the main economic driver (think Green Bay Packers), generating nearly $65 million in revenue.
In Wisconsin, 97 percent of communities depend on groundwater as a drinking-water source, yet nearly 40 percent of the wells are contaminated in the northeast with nitrates and a veritable stew of fecal bacteria. Stricter standards for manure disposal were recently approved in 15 eastern counties in Wisconsin, but not in southwestern Wisconsin where groundwater contamination is equally problematic. Concentrated animal feeding operations (CAFOs) are under greater scrutiny lately, and other progress has been made, but one question looms large: Is this the best we can do?
It’s becoming increasingly clear that land uses and the quality of our water are inextricably linked, and local units of government hustle to patch together a water-protection strategy to curb contamination from a variety of sources—animal and otherwise. Federal mandates, now with a greater regulatory focus on nonpoint source pollution, can do some of the work to protect surface waters and groundwater, but real success will come from local buy-in and political will. Decades after our cities and communities established local industries and bustling economies, we try to take a step back and minimize real and potentially irreversible damage to water quality.
Keep the Village Well Clean
We have an intuitive understanding of what’s needed to keep water clean. In his 2017 book Drinking Water—A History, James Salzman covers the history of drinking water from Roman times to present. If this seems like a huge topic, you’d be right. In this lengthy book, Salzman takes us through horrific cholera outbreaks and the era of big, stinking cities struggling to manage human waste to new discoveries related to the transmission of disease, all of which changed our perception of what is drinkable water.
Salzman also cites plenty of historical texts that show an early awareness of source-water protection. Some of the first environmental laws in England were those requiring the collection and removal of “night soil” from the streets of London. Other communities in Africa and Australia had rules about prohibited activities near wells and streams.
Modern water-planning principles recognize the importance of the watershed in terms of source-water protection. Students of land-use planning are taught to consider multiple site-specific factors in a planning project, ranging from physical, hydrogeologic and geologic characteristics to land uses and ground cover. Large-scale, holistic approaches to source-water protection can be a challenge to implement for a number of reasons: political road-blocks and the practical difficulties of upending established patterns of development and growth are a few. Under the best of circumstances, we hope for a patchwork of initiatives throughout the watershed that collectively minimize the greatest threats to water quality.
An Asset Worth Billions
An ideal approach is integrated and considers the multiple ways in which water enters the human ecosystem, moves through it and exits. New York City’s municipal drinking-water system was put in place in the mid 1800s, and has been modified and updated regularly through the years to accommodate the needs of a growing population. To date, the system is a pillar of excellence in watershed planning and engineering, and claims to have one of the largest unfiltered municipal water-supply systems in the country.
New York City has invested billions to protect one of its greatest assets: the drinking water that comes from the Catskill/Delaware watershed in upstate New York. On a daily basis, more than 1 billion gallons of water are supplied to more than 9 million New Yorkers through an extensive water-supply system consisting of 19 reservoirs and three managed lakes. Relying on gravity to move water often dubbed the “champagne of drinking water” through 7,000 miles of aqueducts, water mains and tunnels, the system boasts the ability to provide high-quality tap water without the use of costly filtration treatments.
As can be expected, the entire system depends heavily on monitoring. Multiple robotic rafts afloat in the reservoirs collect and transmit data constantly, and field scientists also take samples, all of which amounts to millions of water-quality measurements annually. These data are analyzed via computer, which generates current readings relating to quality and quantity, and anticipates problems relating to upcoming rain events, increased turbidity from stormwater runoff and other issues.
As the frequency of contaminated wells and waterways increases, the momentum to do what was previously considered impossible will change as well.
Minding the Watershed
To protect New York City’s critically important supply of water, the city relies on managing a watershed that includes nearly 1 million acres. Nearly half of the land is owned by conservancies, the city and the state of New York. The land uses in the watershed determine the quality of the rivers and streams that supply the city’s downstream reservoirs, and New York takes the job of overseeing those land uses seriously; it has strict land-use agreements with all private landowners.
A sizable portion of New York’s latest investment was used to update the wastewater facilities that discharge treated waste into the incoming tributaries. Other funds are used to update aging septic systems in the watershed. It’s clearly a holistic approach that attempts to manage more than the obvious sources of pollution. Tunnels and aqueducts, monitoring systems and other parts of the built infrastructure also need to be in excellent working order. Clearly, even this state-of-the-art drinking-water system will have weaknesses, but New York does more than most municipalities—a fraction of New York City’s size—to protect its source water.
A Tough Lesson to Learn Late
States and municipalities are learning (in some cases, after a water source has been contaminated) to protect the water supply with a near-militant degree of discipline and oversight. Under the best circumstances, this management approach uses a variety of tools.
Each region and watershed has its own set of unique characteristics, from the community’s culture and traditions to the physical features that define the land to the particular mix of urban and rural spaces as well as associated land uses. Kewaunee County, Wis., (just east of Brown County) is home to multi-generational farmers who want to use the land as they always have; for these families, change in farming practices will need to come incrementally. In the Catskill/Delaware watershed in New York state, tools such as conservation easements are used by private property owners and the state to permit only specified land uses.
The options are many, and communities are encouraged to think creatively. Some would say that historic and existing patterns of development are entrenched. I would say that as the frequency of contaminated wells and waterways increases, the momentum to do what was previously considered impossible will change as well.