Table 1.

Concentration of Salmonella spp. (MPN/g TS) in sewage sludge samples collected from the five WWTPs in 2011

Date	WWTP 1	WWTP 2	WWTP 3	WWTP 4	WWTP 5
Jan	<0.006473	<0.006473	<0.006473	0.43	<0.006473
Feb	<0.006473	1.74	<0.006473	0.49	0.43
Mar	<0.006473	3.72	NP	<0.006473	<0.006473
Apr	<0.006473	6.03	<0.006473	0.21	<0.006473
May	<0.006473	4.81	<0.006473	<0.006473	<0.006473
Jun	<0.006473	5.63	<0.006473	NP	<0.006473
Jul	<0.006473	2.28	NP	1.32	<0.006473
Aug	<0.006473	12.20	NP	<0.006473	<0.006473
Sep	<0.006473	3.29	NP	0.69	<0.006473
Oct	<0.006473	1.66	<0.006473	0.76	<0.006473
Nov	0.75	5.74	NP	0.85	<0.006473
Dec	<0.006473	4.45	<0.006473	1.86	<0.006473

NP = Not Performed.