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Water Quality

  •  In the Christina River watershed, water quality has improved since 1995 but nutrients and bacteria continue to be a problem.

Dissolved oxygen (DO) and total suspended solids (TSS) – two basic water quality parameters – have improved across the watershed and consistently meet water quality criteria.  Bacteria levels have improved across the watershed, but continue to violate the state and USEPA’s water-quality standards.  Nutrient pollution (nitrogen and phosphorous) continues to be a problem, with phosphorous levels getting better in some places (but still exceeding criteria) and nitrogen levels worsening in most places.

Christina Water quality trends

Click chart above to view actual size.

  • Stormwater runoff is the main threat to water quality in the watershed.

    Christina Watershed Land Use

    Christina Watershed Land Use

The Christina River watershed is highly developed with 59% of the land use classified as urban.  There is a strong correlation between land use and water quality.  – Greater population and urbanization/suburbanization are generally associated with poorer water quality. – More agricultural and natural lands (forest/wetland) are generally associated with higher water quality, except that there is some association between agricultural lands and higher bacteria levels.

  • PCBs are hazardous industrial chemicals that can cause cancer and have been found in the Christina River. 

PCBs are no longer manufactured in the U.S., but are still present on sites where they were used in the past and they take a very long time to break down.  They make their way into streams from wastewater discharges and water running off the surface and through the ground of contaminated sites. In 2009, 32 sites were evaluated by DNREC and six were found to be the main contributors of PCBs to the Christina River.  Cleaning up and/or controlling PCBs from these contaminated sites should be a top priority for reducing and eventually eliminating PCBs in the Christina River.  (Link to Chemical Contaminants page).

  • Improving water quality is the responsibility of individuals and private and public entities that live, work, and play in the watershed.

Water quality in the Christina Basin can be improved by individual actions on the land as well as the actions taken by organizations throughout the watershed. (Link to “Take Action” webpage).

Charts for Individual Water Quality Measures

(click chart to view actual size).


TMDL stands for Total Maximum Daily Loads


TMDL stands for “Total Maximum Daily Loads”

Christina Dissolved solidsWQ2WQ3