Description of the Indicator
This indicator measures two key parameters of water quality (pH, which is commonly used to measure acidity in water, and total dissolved solids). Stream water quality monitoring is conducted at several sites along the Susquehanna River and adjacent watersheds.
A pH of seven represents a neutral measurement. A value greater than seven indicates basic or alkaline conditions, and values less than seven indicate acidic conditions. The pH of natural waters is between 6.0 and 8.5. Any values less than 4.5 or above 9.5 tend to damage ecosystems severely.
The total dissolved solids (TDS) concentration measures water’s dissolved materials. These materials include sodium, calcium, magnesium, and others. Fresh water usually has TDS levels between 0 and 1,000 mg/L, depending on the region’s geography and contributing factors. Values over 500 mg/L are considered elevated and can be unsuitable for drinking or household use. Although TDS is not considered a primary pollutant, water with a high TDS concentration may indicate elevated levels of ions such as aluminum, arsenic, copper, lead, nitrate, and others that do pose health concerns.
Why is it important?
Assessing PH and total dissolved solids provides valuable information for monitoring water quality, identifying pollution-related challenges, protecting aquatic ecosystems, and facilitating sustainable watershed practices.
How is the region doing?
The Susquehanna River tested at an average of 7.54 pH in the most recent year, or slightly more alkaline than neutral water. The average in 2024 is an increase from the previous year’s average of 6.91 by 9.1 percent. Since 2013, TDS levels in the Susquehanna River have remained below 200 mg/L. Although values increased 10.6 percent from 2023 to 2024, they are still 27.7 percent lower than highs recorded in 2015.