Table 2: Means and variability of nutrient concentrationsa in biosolids collected and analyzed in Pennsylvania between 1993 and 1997 [12].

Nutrient Total Kjeldahl N (%) NH4-N (%) Organic N (%) Total P (%) Total K (%) Mean 4.74 0.57 4.13 2.27 0.31 Standard deviation 1.08 0.30 1.03 0.89 0.27

aConcentrations are on a dried solids basis.