Table 3.

Soil and Biosolid analyses as stipulated by The Sludge Directive [156].

S/N	Soil Analysis	Sludge Analysis
Frequency	Determined by soil mass.	Bi-annually or annually if there's no change in parameters.
Sampling method	Samples should be taken from 25 cm below the surface and not less than 10 cm minimum depth, a minimum of 25 core samples of soil over an area of 5 ha should be taken.	Wet or dry sludge samples can be used for analysis.
Parameters	To be tested should include Zn, Pb, Ni, Cd, Cu, Cr, and pH.	Should include organic matter, pH, dry matter, Zn, Pb, Ni, Cd, Cu, Cr, pH, Hg, N, and P.
Test method (s)	Atomic absorption spectrometry	Atomic absorption spectrometry, Spectrophotometry.