Industrial Factors Contributing to Marion’s Water Crisis?Reading Mode

Marion’s Water Source

Marion, Ohio drinking water is managed by Aqua Ohio and is unique because it uses a dual-source system consisting of both surface water and groundwater. The primary source for the Marion Water Treatment Plant is surface water drawn from the Little Scioto River. Aqua uses an intake system drawing water from the Little Scioto River, then storing the water, because river levels can fluctuate. Aqua Ohio also utilizes off-stream reservoirs to store this water. These reservoirs ensure a steady supply even during dry periods or when river water quality isn’t ideal for immediate treatment. Aqua’s reservoirs are located immediately adjacent to the Marion Water Treatment Plant on Marion-Agosta Road, just west of the city. This system has worked for Aqua for decades.

Watershed Levels for Winter 2025-2026

Watershed flow in the Little Scioto River was significantly below normal during the winter of 2025-2026. By December 2025, regional reports from the Ohio State University Agronomic Crops Network and the U.S. Drought Monitor indicated that northwest and central Ohio were experiencing “Extreme Drought” (D3) conditions. Precipitation deficits were as high as 9 to 12 inches below normal in the months leading into the winter. In some nearby watersheds, monthly average flows were recorded at only 2% of their historical levels.

The Little Scioto is a smaller tributary, but it followed this trend, leading to the low river and reservoir levels reported. The low river flow directly impacted water, because there was less water to dilute naturally occurring organic compounds, a substance called geosmin bloomed in the Little Scioto. The geosmin impacted water quality leading to a noticeable change in taste and odor. Aqua Ohio took subsequent measures to mitigate these blooms by drawing from wells that used ground waters from aquifers, and manipulating the plant’s treatment process.

Industrial Water

The two largest industrial water influencers are The National Lime and Stone Company and Poet Marion. Both have major impacts on Marion’s watershed and aquifers. National Lime and Stone Marion contribute substantially to the Little Scioto watershed, while Poet Marion consumes water.

National Lime and Stone Company Marion

National Lime and Stone draws nearly 750 million gallons of groundwater annually. The stone quarry does this for two primary purposes: dewatering and processing. For dewatering, they pump groundwater out of the quarry pits to keep the working area dry. This accounts for the vast majority of their withdrawal. For processing, water is used to wash crushed stone and aggregates to meet specifications.

The effects of the National Lime and Stone Company on residents in their immediate vicinity have been chronicled for years. Complaints of dry wells, unusable well water, and more, have been lodged against the company for years. The company uses a series of sediment ponds to allow solids to settle out of discharge before they eject millions of gallons of water into the ditches and creeks that are tributaries of the Little Scioto River. The Ohio EPA requires the company to monitor water discharge for pH levels and total suspended solids (TSS) to ensure the discharge doesn’t harm the local aquatic habitat.

There is a low likelihood that the water discharged by the quarry is promoting geosmin growth. Water discharged from this facility is primarily ground water and is low in phosphorus and nitrogen. The site does discharge some TSS into the watershed that can cause changes in light penetration and water temperatures, leading to algae growth. During low water level periods like the period in the winter of 2025-2026, the discharge of the National Lime and Stone Company accounts for a substantial portion of the water in the Little Scioto River. This disproportionate balance in natural surface water and ground water discharged from the quarry may result in an imbalance that promotes geosmin blooms.

Poet Biorefining Marion

Consumption

Poet Marion consumes a massive amount of Aqua Marion’s water supply. Estimates indicated that the facility intakes 350-450 million gallons of water annually. To put this in perspective, Aqua Ohio provides approximately 2.3 billion gallons of water to all of their Marion customers, annually. Poet consumes 15-25% of Aqua’s water supply.

Poet Marion has an annual production capacity of 150 million gallons of bioethanol, with the average water consumption of approximately 2.33 to 3.0 gallons of water for every gallon of ethanol produced. Poet uses a process called Total Water Recovery (TWR), which recycles cooling water and process water internally. This allows the facility to have below average water consumption for production levels.

Poet has invested in the Aqua Ohio infrastructure that facilitates their water use, but a heavy consumption strain is placed on the public water supply. While Aqua maintains that their water treatment facilities are capable of this load, seasonal low watershed in the Little Scioto is out of Aqua’s control. During peak periods, the city uses nearly 87% of Aqua’s available treatment capacity.

Discharge

According to the Ohio EPA National Pollutant Discharge Elimination System (NPDES) permit (No. 2IF00025*FD), Poet Marion has two primary outfalls. Outfall one is the primary operational discharge point, with effluent loadings based on an average design flow of 236,000 gallons per day. This discharge is strictly limited to cooling tower blowdown, reverse osmosis reject water, multimedia filter backwash, and water softener regeneration water. Outfall two is used for uncontaminated storm water runoff, cooling tower maintenance discharge, and fire system testing water.

Discharge from outfall one is regularly monitored for TSS, pH, and phosphorus. However, Nitrogen and Phosphorus have no predetermined limit under Poet Marion’s 2025 permit. Poet Marion must complete an “Evaluation for Reducing Discharge of Phosphorus” form as part of a statewide Ohio EPA initiative to track industrial nutrient loading. The facility reports their phosphorus discharge levels but has no cap on these levels. Poet uses filtration and reverse osmosis systems to purify intake water, which serves to multiply mineral and solid levels in the discharge waters. Poet then discharges into the Rock Swale Ditch and Little Scioto River, potentially elevating levels of Phosphorus and Nitrogen that drive geosmin blooms.

Does Industrial Water Use Degrade Our Water Supply?

Unfortunately, the citizens of Marion do not have an answer to this question. Did the winter of 2025’s historically low watersheds in the Little Scioto River become altered by the discharge of millions of gallons of ground water from National Lime and Stone Company? Did disproportionate discharges of phosphorus and nitrogen, in Poet Marion’s discharge water, promote the growth of geosmin?

According to 2025 Ohio Department of Agriculture reports, over 80% of nitrogen and phosphorus in this region comes from agricultural runoff from corn and soybean fields rather than industrial sources like Poet. Considering that Poet Marion consumes 50 million bushels of corn—more than four times the amount grown in Marion County—from a radius of up to 60 miles, there is likely an indirect causality from agricultural runoff and possibly a direct causality from facility discharge. Will the Ohio EPA, Aqua Ohio, and industrial users be able to end this cycle of water quality concerns, or will the residents of Marion remain on a monthly cycle of unreliable water quality and safety?