2. Usar unos kits económicos que traen unos reactivos para echar a una muestra de tierra y comparando color averiguar el pH. El pH puede ser ácido, neutro o alcalino. Si es alcalino, lo más probable es que contenga mucha cal (suelo calizo).

This network tests samples of Mississippi River water for the presence of volatile organic compounds, polychlorinated biphenyls (PCBs), acid/base neutrals (ABNs), chlorinated organics, and phenols at all three sites on a quarterly basis. From January 2000 to August 2003, 116 sites across the state were sampled for the above classes of compounds, including the three Mississippi River sites.