Table 3.

Molecular detection of SARS-CoV-2 RNA in wastewater samples. Collected samples were tested at t0 and at t1 = 24 h, with subsamples being kept at room temperature and at 4 °C. Two RT-qPCR assays were performed on all extracts, targeting genes N and Orf1b, with an estimated limit of detection (LOD) of 2.5 gc/L (Chu et al., 2020). Average recovery for enveloped viruses from wastewater with the adopted ultrafiltration protocol is estimated at 22% (Ye et al., 2016).

Sampling date: 23/04/2020
Plant		t0		t1 (r.t.)		t1 (4 °C)
	ID	N	Orf1b	N	Orf1b	N	Orf1b
WWTP_A	A-U-1	+	+	−	−	−	−
	A-U-2	−	−	−	−	−	−
	A-U-4	+	−	−	−	−	−
WWTP_B	B-U-1	−	−	−	−	−	−

Sampling date: 05/05/2020
Plant		t0		t1 (r.t.)		t1 (4 °C)
	ID	N	Orf1b	N	Orf1b	N	Orf1b
WWTP_A	A-U-1	+	−	−	−	+	−
	A-U-2	−	−	−	−	+	−
	A-U-3	−	−	−	−	−	−
	A-U-4	+	−	−	−	−	−
	B-T-1	+	−	−	−	+	−
WWTP_B	B-U-1	−	−	−	−	−	−
	B-T-1	+	−	−	−	−	−