Table 1.

Comparison of United States (USEPA) and Swedish (SEPA) environmental protection agency alkalinity classification schemes. The breakpoint indicates the highest alkalinity values at which a classification can be applied. The lowest alkalinity value for a class is indicated by the breakpoint in the row immediately above. For example, the SEPA “Poor buffering capacity” class applies to water bodies with alkalinity values between 50 and 100 µeq L⁻¹

Breakpoint (µeq L−1)	USEPA	SEPA
0	Acute
20	Severe	No or insignificant buffering capacity
50	Elevated	Very poor buffering capacity
100	Moderately acidic	Poor buffering capacity
200		Good buffering capacity