Infrastructure Under Water
Climate change stresses aging water infrastructure
Summary: Aging infrastructure and extreme precipitation in the Northeast are overwhelming outdated stormwater systems that degrade water quality and create health hazards. In Schenectady, NY, the Hans Groot Kill has profound sewage contamination, with bacteria levels failing EPA standards 99.7% of the time over the last five years. Chloride toxicity and microplastic pollution further indicate degraded conditions. Analysis of fluoride reveals that municipal water accounts for a third of its flow in normal conditions. While Schenectady has initiated remediation, sustainable solutions that are climate smart will require modernizing infrastructure, community collaboration, and leveraging funds like the $100 million that may soon be allocated by the 2024 Water Resources Development Act for the Mohawk Watershed.
Aging infrastructure and an increase in extreme precipitation are straining sanitary and stormwater systems across the Northeast, leading to a decline in water quality that is locally a health hazard. The increase in rain - and big rainfall events - is too much for our old pipes: the pipes just can’t handle this much water, and they weren't designed to. Despite the recent drought, intense precipitation events have increased in the last two decades by about 50% here in the watershed, particularly in summer [1,2,3]. These heavy rains overwhelm stormwater systems, often leading to sewage overflows. Rising annual precipitation and extreme rainfall in the Northeast are straining outdated stormwater and sewer systems, and this can lead to enteric disease [4,5,6].
Urban hydrology involves a myriad of pipes and culverts that carry wastewater, sewage, and drinking water. When the system fails, our surface waters suffer. This culvert has broken and is offset due to settlement of the overlying road, and the offset is a suspected cause for a broken sanitary sewer and stream contamination (photo: J Wright, 11/21).
The Hans Groot Kill (HGK), a small urban stream in Schenectady, NY, has been incorporated into the city’s stormwater collection system. Our analysis using fecal indicator bacteria (Enterococcus) has revealed widespread contamination from sewage. Over the past two years, every sample that we collected and analyzed exceeded the EPA beach advisory value. We took samples at low flow, at high flow, and in between, and every single sample failed. There is overwhelming evidence that points to untreated sewage entering the HGK through failing sanitary sewer lines, likely due to exfiltration or outward leaking. While rainfall events correlate strongly with high pathogen levels, elevated fecal bacteria levels also occur in low-flow conditions, which indicates that some sewage leaks are persistent and chronic. Pipes are broken, corroded, or otherwise impaired. The HGK is not an anomaly: aging infrastructure and extreme storms are presenting an enormous public health challenge now and in the foreseeable future in New York, the Northeast, and elsewhere.
The HGK has long been integrated into the city’s stormwater system, but in the past it was also part of combined sewage overflow (CSO). The CSO system was phased out over a decade ago, so now the HGK should handle only urban stormwater. Despite efforts to modernize and separate stormwater and sanitary sewer systems, our findings show persistent and troubling levels of sewage pollution in the Hans Groot Kill.
The HGK has been plagued by sewage overflows in the past, particularly during heavy rain events, and this was because sewage was allowed to flow when the regular sanitary sewer pipes couldn't handle the volume during rain events. The HGK, historically called “the creek that reeks,” flows through Schenectady’s historic General Electric Realty Plot and Union College campus before running underground and discharging directly into the Mohawk River near Rivers Casino. Historical use as a CSO gave it a well-deserved reputation and nickname. Despite significant improvements since the Clean Water Act of 1972, including the transition from a CSO system to a municipal separate stormwater sewer system (MS4), the creek remains impaired, even though discharge of sewage into this creek is illegal.
Schenectady resident Tom Capunao wants to see an end to the sewage in the HGK, so he addressed the Mayor and City Council in the fall of 2023: “Mr. Mayor, Councilmembers, I’m here tonight, Tom Capuano, to express my concern about the leaking sanitary sewer pipes that have been contaminating the Hans Groot Kill. The levels of bacteria are dangerous for everyone living in the area along that creek, and even more dangerous for those taking drinking water from sources downstream.” Part of the response from the Mayor to Tom’s comments was that “...that condition has existed for decades,” which may mean that the baseline has shifted so far that this is now our new normal. Tom is part of the Downstream Justice project of the Social Justice Action team at the Unitarian Universalist Society of Schenectady, which is an important stakeholder in HKG remediation efforts [07]
A key tool in understanding water quality is pathogen testing. Here Eva Willard-Bauer and Jacquie Smith prepare to take a sample for Enterococcus from the Hans Groot Kill, a contaminated urban creek in Schenectady (photo: JI Garver, 4/2019).
Tom is not alone, and many residents along the HGK know that the water is contaminated. When doing some sampling in the creek a few years ago, I ran into a resident who was a pediatrician. We talked for some time because he was interested in what I was up to, and then later he contacted me after reading a few of the papers we had published on water quality and contamination. He noted how common it was to see kids playing in the water and he was “...alarmed regarding the public health consequences as this goes unremediated.”
Our sewage pipes are cracked and broken in innumerable places, almost all underground and out of sight. This means that sewage can leak out into the ground (exfiltration) and it also means that rainfall leaks into these pipes. Thus these municipal sewer lines are an open system: sewage leaks out and water leaks in. Paul Lafond, the General Services Commissioner for Schenectady, recently provided numbers that highlight the severity of the problem. At a public forum in May 2024, he noted that sanitary sewer and stormwater drainage systems are mixing, and they are not supposed to. Because our stormwater and wastewater are now separated, wastewater runoff in sanitary sewers should theoretically have a steady flow, even when it rains. However, he noted that the amount of water sent to the Schenectady wastewater treatment plant increases significantly during storms from a normal 12 million gallons to more than 40 million gallons during periods of rain [08]. This ~200% increase means our pipes are porous and leaky, and their contents can freely exchange with the environment. Let’s look at the details of four water quality indicators:
Sewage indicators. Since 2018, our research team has conducted extensive water quality monitoring in the HGK and other local waterways [1,2,10,13,14,18,20,24,25,26,27,29]. The HGK is by far the most contaminated and most consistently contaminated - it is in a league of its own. We have collected and analyzed over 300 water samples from the HGK for fecal indicator bacteria, it has a failure rate of 99.7% based on the EPA beach advisory value. These results highlight ongoing public health risks associated with the creek, especially considering the fact that it is the natural centerpiece of the Union College Campus. In 2020, after a CDC-reportable outbreak of giardia, the College put up warning signs along the creek that read “Caution: Do not enter the creek, No swimming or wading allowed.”
Our work has focused mainly on using Enterococcus, a fecal indicator bacteria (FIB), to assess contamination by sewage. High concentrations of Enterococcus suggest the presence of other pathogens, including bacteria, viruses, and parasites. A number of well-known pathogens can cause enteric disease when people in the community, including children and college students, are exposed to the water, generally through accidental ingestion.
During low-flow conditions, contamination levels are typically 10 times the EPA threshold, while high-flow levels are 100-1,000 times higher. Despite initial remediation efforts by the City, there is no significant improvement in contamination levels, though factors such as ongoing variability of rainfall and time of testing complicate direct year-to-year comparisons.
Although the HGK contributes a relatively small water volume to the Mohawk River, its high contamination levels impact the River. Data from Riverkeeper and partners show the poorest water quality in this section of the River occurs at Mohawk Harbor, just downstream of the confluence with the HGK [9]. Ironically, water quality improves farther downstream at a sample site beyond the sewage treatment plant. What is remarkable about this result is that Mohawk Harbor is a flagship effort by the City (and the State) to engage with the River, and we’re doing it where the river water is most contaminated.
“Sewer surge” is one way to think of how urban streams like this respond to rainfall events. Many of our urban creeks are conveyed by pipes and culverts, all part of our water infrastructure. Here the HGK surges after a rainfall event (Photo: JI Garver, 11/2021).
Chloride indicators. Chemical analyses reveal that the creek is so salty that few freshwater organisms can survive [10]. Chloride and its companion sodium, are an ionic pair that is present in our daily lives as table salt, and too much of them are not good for your health. The HGK has extremely high levels of chloride, primarily from road salt and possibly also from municipal wastewater. During winter and early spring, chloride concentrations can reach levels equivalent to ~30% of seawater, and such a salty environment poses significant risks to aquatic life accustomed to freshwater conditions [10]. Salinity in the HGK reaches the highest concentrations in the winter and then starts decreasing in early spring. In the late summer and fall, well after the road salt season, salinity levels never go down to normal. This is because we’ve over-salted the environment and it would take decades to wash away if we quit road salt “cold turkey” tomorrow.
Studies confirm that streams in urban areas with impervious surfaces, such as the HGK, frequently exceed EPA chloride toxicity criteria. In the US, chronic chloride toxicity occurs at 230 mg/l, and acute toxicity at 860 mg/l (Canadian standards, which have a different scientific basis, are lower). The HGK exceeds acute levels throughout much of the winter and remains at chronically toxic levels the rest of the year [10]. Thus this creek has an impaired ecosystem due to chloride toxicity alone, sewage aside. And all that chloride is incredibly corrosive, constantly attacking and dissolving metal pipes.
“Urban Karst” is a term for the macropores and subterranean feeder pipes that affect the hydrology - and pollution - of urban streams [11]. Here feeder pipes of different ages and stages of decay feed the HGK in its headwaters (photo: JA Smith)
Fluoride indicators. In communities with fluoridated water added for dental health, fluoride can be used as a tracer to identify municipal water—whether from leaks, cracks, or illegal discharges—entering streams and rivers [12]. While fluoride concentrations are similar in drinking water and wastewater (both “municipal water”), the latter is a more serious concern due to the presence of pathogens. Understanding stream chemistry and pathogen levels is particularly critical during low-flow conditions, where base flow dominates. In urban areas, base flow can include regular groundwater, but also groundwater from abandoned and active pipes and flow through artificial fill—collectively referred to as “urban karst.”
We studied fluoride in the HGK under both low-flow conditions (<0.02” rainfall in 48 hours) and high flow conditions following a rainfall event [29]. Our 2023 and 2021 data revealed that municipal water (either sewage or drinking water) significantly contributes to flow in the HGK. We discovered that during low-flow periods in the fall of 2023, municipal water accounted for 20–40% of the creek’s volume, averaging ~33%. High-flow events that occur after rainfall showed more variability, with municipal water typically contributing 20% or less, which is expected due to the dilution effect of rainwater. This fluoride-based analysis highlights the remarkable role that municipal water plays in sustaining discharge in the HGK, and illustrates the “leakiness” of our water infrastructure.
While we could use fluoride to demonstrate that municipal water is a significant component of the typical HKG flow, we could not distinguish between inputs of either drinking water or wastewater (or both, which is common in other urban settings). But there is a hidden warning in these data because we could not rule out leaks in drinking water pipes, and there are good reasons to hope that that part of the system is closed and not susceptible to environmental contamination.
Plastic indicators. Microplastics are a leading indicator of impaired surface water and sewage pollution, and there are a whole host of problems associated with high microplastic loads in surface waters [16]. The first study of microplastics in the Mohawk River was conducted by Dr. Jacquie Smith and students at The College of Saint Rose and then at Union College [17,18,19]. They focussed initially on the main stem of the Mohawk River and subsequently on 21 tributaries. Every sample collected contained microplastics. One question they were addressing in the tributary study was how much small streams contribute to the microplastic load in the River. An emerging focus was the role of the HGK and other urban streams in the watershed. The study identified three main pathways for microplastics to enter the river: surface runoff from urban areas where plastics are discarded, wastewater treatment plants (WWTPs) unable to filter small particles, and stormwater outfalls and combined sewer systems (CSSs), which release plastic waste during heavy rains.
While the Mohawk and its major tributaries showed lower microplastic concentrations (0.2–1.5 particles/m³), smaller urban streams such as the HGK, North Chuctanunda Creek in Amsterdam, and Canajoharie Creek in Canajoharie showed higher concentrations (6–12 particles/m³) under normal conditions. During high flow events, the HGK had concentrations that were 35 times its usual levels (>206 particles/m³), a finding that reinforces the severe impact that storm-driven debris has on waterways.
Smith and others suggested that microplastic pollution in the HGK is related to sewage contamination that introduces fibers from laundry wastewater and (at the time) microbeads from personal-care products [18]. They concluded that at high flow, the HGK delivers more microplastic particles to the Mohawk River than twenty larger streams combined during low flow, and a primary source is sewage [18].
NYSDEC. Contamination in our surface streams falls under the purview of the New York State Department of Environmental Conservation (NYS DEC). The DEC maintains a water quality inventory for waters across the State, including the 303(d) list of impaired surface waters requiring remediation. A colleague once noted that 303(d) waters are the “baddest of the bad.” The HGK has been included on this list, because it is known to be polluted. However, in the proposed 2020–22 303(d) list that was released in December 2021, the HGK was slated for “delisting” due to "flaws in original analysis" (theirs, not ours). Our research group was surprised by this given the results of our testing.
Following formal comments by our group to the DEC in January 2022, they began additional testing, and the results from 2022 and 2023 confirmed that the HGK failed State standards for surface water quality. Despite these findings, the creek was delisted in the September 2024 revision of the 303(d) list. The recent results, however, would suggest it will get back on the upcoming list. But being on a list doesn’t get it fixed.
A school bus plows through pathogen-rich sewage water that emerges from an overflowing sanitary sewer. We tested this water and it had pathogen levels that were nearly 2000 times higher then the EPA suggested level for contact (JI Garver, 10/2021).
The City of Schenectady has taken significant steps, but future efforts will require community support. In the fall of 2020, following the publication of initial findings in 2019 [20], a small group of concerned stakeholders formed the Hans Groot Kill Working Group. This has been led by retired Union College chemistry professor Tom Werner. The mission of this working group has been to build a partnership with the City, improve communication, and collaborate on solutions. Part of this effort involved the residents of the GE realty plot, a historic district in Schenectady.
The City responded. In the spring of 2021, they conducted Microbial Source Tracking (MST), utilizing the genetic marker HF182 to confirm human sewage as the source of contamination in stream samples. They also initiated an inspection of sewer lines using CCTV cameras to detect leaks. By the fall of 2021, dye testing and inspections of storm and sanitary sewer lines had begun, leading to the identification and repair of some leaks. Some of these repairs included slip-lining, where an internal pipe is installed within a damaged pipe to prevent further leaks.
By March 2023, the City had enlisted the services of MJ Engineering and Land Survey, an environmental and engineering consulting firm from Clifton Park. Since then, the firm has been conducting pathogen testing, additional MST analysis, CCTV inspections, and dye testing to pinpoint leaks. Meanwhile our continued testing still showed impairment [13,14]. In the late spring of 2024, Mayor McCarthy said “It’s like finding a needle in the haystack… We keep chipping away at it, and it’s been frustrating — unfortunate — that we haven’t come up with a clear solution, but we keep working at it. I will tell you, we’re going to solve it.” [8].
Despite this progress and optimism, there is a need for open and transparent dialogue between key stakeholders and information sharing. Moving forward, the City will need the support of residents to navigate the challenging, costly, and disruptive mitigation efforts that lie ahead. This should be a key component in the new City’s comprehensive plan “Electric City Recharged.”
A solution will require teamwork. If most of the community agrees that we would prefer to not have unhealthy sewage in our urban creeks, or that it is unacceptable that sewage gets dumped into the Mohawk River, then we can start working together to solve the problem. This is not the City’s problem, it's our problem. Aging infrastructure and the intermingling of stormwater and sewage are challenges common to many cities in the Northeast (and elsewhere).
This effort should dovetail with climate adaptation strategies. Climate adaptation for municipalities in the Northeast will require an ongoing and expensive effort that needs to be partly focused on safeguarding and improving our critical infrastructure, including water and sewage systems. This is almost certainly one of the grand challenges of our time. The enormity of the challenge lies in rebuilding outdated water infrastructure to handle a changing climate that here in the Northeast appears to be characterized by increased rainfall and extreme precipitation events [1,2]. Much of this infrastructure is nearly a century old and we need to not only put in new pipes, but they need to be bigger.
Addressing this issue will require leadership and community commitment. This leadership needs to first embrace the challenge, and then develop a comprehensive plan, implement it, and navigate the process. Effective leadership must prioritize involving stakeholders in the process. Shannon Leininger, who was part of the Penn State Initiative for Resilient Communities, emphasizes the importance of "collaborative adaptive management," which she defines as focusing on benefits to both public and environmental health. She explains: “The key factors to a successful negotiation are engaging stakeholders, participating in collaborative adaptive management, focusing on mutual gains, and conducting scenario planning. Local governments must keep their constituencies informed and, if possible, include them in the negotiation process” [23].
Significant investment in wastewater and drinking water infrastructure is critical for climate adaptation. Upgrading aging systems and addressing pollution sources will be expensive, but delaying these efforts will only prolong the problem, damage the environment, and endanger public health.
Help may be just around the corner. In early December 2024, the US House of Representatives came to an agreement and passed the Water Resources Development Act (WRDA), which is a must-pass bipartisan water infrastructure bill. That legislation includes $100 million for water and wastewater infrastructure in the Mohawk Watershed that was led by Tonko (NY-20) and Williams (NY-22) with the support of Stefanik (NY-21). In a press release Representative Tonko noted: “With the inclusion of our environmental infrastructure provision, we are delivering critically needed measures to improve the Mohawk River’s health and infrastructure, address growing climate and ecological challenges” [28].
The WRDA funding may have arrived just in time to help cities along the Mohawk River modernize aging water infrastructure and adapt to the basin’s changing hydrology.
This and other Notes from a Watershed are available at: https://mohawk.substack.com/
Further reading
[01] Garver, JI, 2021. Extreme Rainfall in the Northeast: It's raining a lot and our wastewater system is bursting at the seams. The resulting sewage overflows are impairing our waterways. Notes from a Watershed at Mohawk.substack.com (Here)
[02] Garver, JI, 2023. Increased summer rainfall in the Mohawk watershed; Water quality, flooding, and ecosystems are affected by more warm-month rain in the Mohawk Watershed. Notes from a Watershed at Mohawk.substack.com
[03] Plummer, I, and Garver, JI. 2023. Changes in temperature and precipitation patterns in the Mohawk Watershed: implications for flooding, water quality, and ecosystem health. In Mohawk Watershed Symposium, v. 13, p. 54-58.
[04] McGinnis, SM., 2020. Recreation, Rainfall, and Waterborne Disease: How Social, Environmental, and Climatic Factors Influence Waterborne Disease Risk in Areas Impacted by Combined Sewer Overflows. Temple University.
[05] Lynch, V.D. and Shaman, J., 2023. Waterborne infectious diseases associated with exposure to tropical cyclonic storms, United States, 1996–2018. Emerging Infectious Diseases, 29(8), p.1548.
[06] Haley, BM, Sun, Y., Jagai, JS, Leibler, JH, Fulweiler, R., Ashmore, J., Wellenius, GA. and Heiger-Bernays, W., 2024. Association between combined sewer overflow events and gastrointestinal illness in Massachusetts municipalities with and without river-sourced drinking water, 2014–2019. Env. Health Perspectives, 132(5), p.057008.
[07] Social Justice Action Team at the Unitarian Universalist Society of Schenectady (here)
[08] Waite, A. 2024. Solutions murky to pollution of Stream. Daily Gazette, Sunday 22 May 2024.
[09] Riverkeeper, 2024. Pathogen levels in the Mohawk and other tributaries of the Hudson River are routinely measured by Riverkeeper and partners. The website “Water quality in the Mohawk River: Data updates” where these data can be found, is here.
[10] Garver, JI, Ragland, CJ, Wright, J, Manon, MR, Mundell, H, Smith, JA, 2023. Regional salinization in the lower Mohawk River: effects on urban streams, the Great Flats Aquifer, and raw water for municipal use. In Mohawk Watershed Symposium, v. 13, p 11-16.
[11] Bonneau, J., Fletcher, TD, Costelloe, JF and Burns, MJ, 2017. Stormwater infiltration and the ‘urban karst’–A review. Journal of hydrology, 552, pp.141-150.
[12] Lockmiller, KA, Wang, K., Fike, DA, Shaughnessy, AR and Hasenmueller, EA, 2019. Using multiple tracers (F−, B, δ11B, and optical brighteners) to distinguish between municipal drinking water and wastewater inputs to urban streams. Science of the Total Env., 671, pp.1245-1256.
[13] Garver, JI, Smith, JA, 2023. Extreme precipitation and sewage overflows are driving an emerging health crisis: a case study from Schenectady. In Mohawk Watershed Symposium, v. 13, p. 17-22.
[14] Garver, JI., Smith, JA, 2024. Sewage and municipal water in an urban creek in the Northeast: a tale of aging infrastructure. Geological Society of America Abs with Prog, v 56, n. 5, doi: 10.1130/abs/2024AM-404466
[15] Garver, JI and Smith, JA, 2022. Extreme precipitation, aging pipes, and sewage overflow are driving an emerging health crisis: a case study from Schenectady NY. Geological Society of America Abstracts with Programs. v 54, n 5, 2022 doi: 10.1130/abs/2022AM-381636
[16] Wear, SL., Acuña, V., McDonald, R. and Font, C., 2021. Sewage pollution, declining ecosystem health, and cross-sector collaboration. Biological Conservation, 255, p.109,010.
[17] Smith, JA., Hodge, JL., Kurtz, BH. and Garver, JI,, 2017, The distribution of microplastic pollution in the Mohawk River. In Mohawk Watershed Symposium, vol. 09, pp. 67-71.
[18] Smith, JA, Caruso, E. and Wright, N., 2019, Extreme rainfall, high water, and elevated microplastic concentration in the Hans Groot Kill: implications for the Mohawk River. In Mohawk Watershed Symposium, v. 11, pp. 54-59.
[19] Smith, JA., Caruso, E. and Wright, N., 2020, Microplastic pollution in Mohawk River tributaries: likely sources and potential implications for the Mohawk Watershed. In Mohawk Watershed Symposium, v. 12, pp. 53-58.
[20] Willard-Bauer, E., Smith, JA, Garver, JI., Goldman, D., Newcomer, B. 2020. Enterococci levels in the Hans Groot Kill and Mohawk River, Schenectady, NY. In Mohawk Watershed Symposium, v.12, p. 63-68.
[21] Garver, JI. 2022. Extreme precipitation and sewage overflows are an emerging health crisis: a Case study from Schenectady NY. NY State floodplain and Stormwater Managers Association, NY Water environment Association annual meeting (4 May, 2022, Schenectady NY).
[22] Garver, JI, 2020, “Giardia outbreak in the Mohawk Watershed: Thirty-two students at Union College diagnosed”, in Notes from a Watershed at Mohawk.substack.com
[23] Leininger, S, 2021, Storm and wastewater infrastructure infrastructure: Negotiating disputes in the face of Covid and extreme weather events. Arbitration Law Review, 13, Article 9 (2021). (here)
[24] Wright, J. 2022. Sewage and pathogen contamination in urban streams in the Schenectady in the lower Mohawk watershed. Department of Geosciences, BSc thesis, June 2022. 63 p.
[25] Ragland, CJ. Sewer System Infrastructure and Stressors on Water Quality in Stream within the Alplaus Watershed in Upstate NY. Environmental Science, Policy, and Engineering Program, BSc thesis, June 2022. 90 p.
[26] Goodman, J. 2023. Fecal indicators bacteria indicate impairment of surface water quality in the Indian Kill watershed in the town of Glenville. Environmental Science, Policy, and Engineering Program, BSc thesis, June 2023. 34 p.
[27] Phillips, EL., 2024. Water quality of the Kromme Kill and Collins Lake system, Scotia and Glenville New York: Impairment due to septic failure and salinization. Environmental Science, Policy, and Engineering Program, BSc thesis, June 2024. 38 p.
[28] WRDA funding. 4 December 2024 press release: Tonko secures $100 Million investment for the Mohawk River in must-pass legislation. Tonko pushed to include funding for Mohawk River and tributaries in final Water Resources Development act (WRDA) legislation (here).
[29] Garver, JI., Manon, MR, Smith, JA, Pittman, N, 2023. Fluoride as a tracer of municipal water: the Hans Groot Kill case study in Schenectady, NY. In Proceedings of the 2024 Mohawk Watershed Symposium, v. 13, p. 21-26.