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LakeQuality

Ohio vs Pennsylvania, Lake Water Quality Comparison

A data-driven comparison of lake water quality between Ohio and Pennsylvania, built from EPA Water Quality Portal monitoring data.

OhioPennsylvania
Total Lakes173
Average GradeDD
Average Score0.841
Grade A Lakes00
Grade B Lakes00
Grade C Lakes30
Grade D Lakes93
Grade F Lakes50
Oligotrophic (Cleanest)00
Eutrophic (High Nutrient)153
Lakes with Invasives10
Improving Trend21
Declining Trend50

Analysis

Ohio has 17 graded lakes averaging a D (score 0.84), while Pennsylvania has 3 graded lakes averaging a D (score 1). On average water quality, Pennsylvania comes out ahead, though the margin is narrow.Ohio counts 0 Grade A lakes and 0 oligotrophic (clearest-class) lakes, against 0 and 0 for Pennsylvania.

Long-term monitoring shows 2 improving and 5 declining lakes in Ohio, versus 1 improving and 0 declining in Pennsylvania. Dataset coverage varies by state: Ohio has maximum-depth data for 0 lakes and documented fish species on 0, compared with 0 and 0 for Pennsylvania. Where a figure is zero, that state dataset has not yet been ingested — grades there rest on EPA clarity and nutrient measurements alone.

Frequently Asked Questions

Does Ohio or Pennsylvania have cleaner lakes?

Ohio has an average lake grade of D (score 0.84) while Pennsylvania averages D (score 1). Pennsylvania has the better average water quality, though the margin is narrow. Grades are computed from EPA Water Quality Portal clarity and nutrient measurements.

Which state has more graded lakes?

Ohio has 17 graded lakes while Pennsylvania has 3. Counts reflect lakes with enough EPA Water Quality Portal monitoring data to grade, not the total number of lakes in each state.