Volume 32, Supplement –Summer 2026
SUPPLEMENT ISSUE
Supplement
Progress and Expansion of the National Wastewater Surveillance System, United States, 2020–2024
Table 2
Characteristics of samples submitted to the National Wastewater Surveillance System, United States, 2023, 2024, and 2020–2024*
| Samples | 2023 | 2024 | 2020–2024 |
|---|---|---|---|
| Total no. samples tested† | 155,165 | 148,023 | 456,594 |
| Time from sample collection to testing, d, median (IQR) | 3 (1–4) | 2 (1–4) | 2 (1–4) |
| Time from sample collection to reporting to 1CDP, d, median (IQR) | 7 (5–14) | 7 (4–10) | 8 (5–22) |
| Time from sample testing to reporting to 1CDP, d, median (IQR) |
4 (2–9) |
4 (1–7) |
5 (2–17) |
| Sample collection method, no. (%)‡ | |||
| Grab | 20,170 (13) | 20,073 (14) | 58,553 (13) |
| Manual composite | 2,382 (2) | 926 (<1) | 6,106 (1) |
| Flow-weighted composite | 58,552 (38) | 57,404 (39) | 189,379 (41) |
| Time-weighted composite | 73,031 (47) | 68,635 (46) | 200,086 (44) |
| Passive |
1,030 (<1) |
984 (<1) |
2,462 (<1) |
| Sample type, no. (%) | |||
| Untreated wastewater | 116,347 (75) | 104,958 (71) | 353,935 (78) |
| Wastewater post–grit removal | 30,286 (20) | 34,702 (23) | 78,122 (17) |
| Primary effluent | 189 (<1) | 186 (<1) | 465 (<1) |
| Primary sludge |
8,343 (5) |
8,177 (6) |
24,072 (5) |
| Sample management, no. (%)§ | |||
| Local health department | 3,614 (2) | 2,745 (2) | 10,429 (2) |
| State health department | 102,602 (66) | 105,578 (71) | 331,293 (72) |
| Commercial contractor | 23,692 (15) | 13,413 (9) | 58,332 (13) |
| Academic partner program |
25,553 (16) |
26,287 (18) |
56,993 (12) |
| PCR type, no. (%) | |||
| qPCR | 51,768 (33) | 19,656 (13) | 145,494 (32) |
| dPCR | 103,114 (66) | 127,891 (86) | 310,011 (68) |
| Multiple PCR types used |
283 (<1) |
476 (<1) |
1,089 (<1) |
| Endogenous wastewater control, no. (%) | |||
| Pepper mild mottle virus | 98,542 (64) | 96,592 (65) | 277,996 (61) |
| CrAssphage | 9,436 (6) | 10,049 (7) | 30,962 (7) |
| Other | 268 (<1) | 201 (<1) | 670 (<1) |
| None |
46,919 (30) |
41,181 (28) |
146,966 (32) |
| Exogenous wastewater control, no. (%) | |||
| Bovine coronavirus | 88,511 (57) | 109,731 (74) | 270,720 (59) |
| Bovine respiratory syncytial virus | 29,865 (19) | 4,418 (3) | 58,258 (13) |
| Other | 23,011 (15) | 21,821 (15) | 82,648 (18) |
| None |
13,778 (9) |
12,053 (8) |
44,968 (10) |
| No. samples sequenced for SARS-CoV-2 | 45,824 | 40,748 | 114,394 |
*1CDP, One CDC Data Platform (https://www.cdc.gov/data-modernization/php/one-cdc-data-platform/index.html); dPCR, digital PCR (including droplet digital PCR); IQR, interquartile range; qPCR, quantitative PCR. †Samples were counted based on unique sample identifications; if a sample was tested for multiple targets, the sample was only counted once. ‡Sample collection methods were determined using the most recent collection-method record associated with each sample. Collection method information may be missing for some samples, and a small number of samples were associated with multiple collection methods. §Sample management counts were not mutually exclusive. Samples could be associated with >1 management category.
1These first authors contributed equally to this article.