There are several options available for cyanobacteria and cyanotoxin analysis. As the needs of each utility are unique, so will your analysis methods be.
- In-house algae identification
- Algae Lab – Trained phycologist can identify algae to the species level and provide numerical count of predominant algae.
- Toxin analysis -Analysis can be performed in-house or sent to qualified laboratory.
There are benefits and limitations to every option and so it may be useful to overlap or combine methods.
| Analysis | Toxins | Limitations | Skill Level | Approximate Cost per analysis |
|---|---|---|---|---|
| Abraxis Strips/Tube | Microcystin 0.3-10ppb Cylindrospermopsin 0-10ppb Anatoxin 0-2.5ppb | Strips are a qualitative – best used as a screening test for presence of toxins. Should confirm results with ELISA or LC/MS/MS | Moderate | In-house -$25 |
| ELISA kit | Microcystin Cylindrospermopsin Anatoxin Saxitoxins | ELISA is a quantitative test – Indicates total toxin does not identify microcystin congeners | Intermediate | Capital cost -$25,000 In-house – $50 Lab – $125-$150 |
| LC/MS/MS | Microcystin Cylindrospermopsin | EPA Method 544 & 545 quantitative – Indicates specific congeners of toxins not total toxins. It is possible to have a non-detect (microcystin) with method 544 and positive result with ELISA | Advanced | Lab – $250-$500 |
Algae identification pictures and resources, as well as links to labs that offer certified toxin analysis ELISA and LC/MS/MS, can be found in Appendix C.
Depending on the toxin results of the raw water monitoring, finished water monitoring may be required. A water system may also consider treatment train monitoring and distribution system monitoring if cyanotoxins are present in the raw water.
B. Initial Finished Water Monitoring
If cyanotoxins are detected by a Public Water System in raw water, the water system should begin finished water monitoring for the detected cyanotoxins according to the schedule in Table 5 (see Appendix C for sampling details):
Table 5: Initial Finished Water Sampling Schedule
| Sample Location | Sample Frequency | Result – Cyanotoxins Detected* | Result – Cyanotoxins Detected in Raw but Not Finished Water | Result – No Cyanotoxins Detected in Raw or Finished Water |
|---|---|---|---|---|
| Entry point to distribution system | 2 times per week | Collect confirmation sample within 24 hours; if confirmed proceed with follow-up sampling per schedule below | Continue raw and finished water sampling 2 times per week until cyanotoxins are not detected in raw water | Continue raw water sampling 2 times per week until bloom is gone (discontinue finished water sampling) |
*Report cyanotoxin analytical results to the Division of Drinking Water within 24 hours of receipt
C. Follow-up Finished Water Monitoring Frequencies after Detecting Cyanotoxins
If cyanotoxins are detected by a Public Water System in finished water, the water system should continue finished water monitoring for cyanotoxins according to the schedule in Table 6:
Table 6: Follow-up Finished Water Sampling Schedule
| Detection Level in Finished Water | Sample Frequency | How Long? | Then What? |
|---|---|---|---|
| Cyanotoxins below Health Advisory Levels for Infants and Young Children* | 2 times per week | Until below detection in finished water and below detection in 2 consecutive raw water samples | Sample raw water 2 times per week if bloom exists; discontinue raw water sampling if bloom is gone |
| Cyanotoxins above Health Advisory Levels for Infants and Young Children* | Daily | Until <0.3 μg/L (microcystins) or <0.7 μg/L (cylindrospermopsin) in 2 consecutive finished water samples, 24 hrs. apart | Sample raw water 2 times per week if bloom exists; discontinue raw water sampling if bloom is gone |
| Cyanotoxins above Health Advisory Levels for Adults** | Daily | Until <0.3 μg/L (microcystins) or <0.7 μg/L (cylindrospermopsin) in 2 consecutive finished water samples, 24 hrs. apart | Sample raw water 2 times per week if bloom exists; discontinue raw water sampling if bloom is gone |
*0.3 µg/L for microcystins; 0.7 µg/L for cylindrospermopsin
**1.6 μg/L for microcystins; 3.0 μg/L for cylindrospermopsin
D. Acceptable Analytical Methods
A Public Water System should choose an analytical method suitable to the water being sampled and the intended use of the results. For source water and raw water monitoring, ELISA (enzyme-linked immunosorbent assay) field kits, which can provide rapid semi-quantitative results, and Immunochromatographic Strip Tests are acceptable. For finished water analyses, a laboratory certified in the use of approved analytical methods for quantifying cyanotoxins, such as ADDA specific ELISA for microcystins, should be used. Appendix D lists the acceptable analytical methods for the analysis of water samples for cyanotoxins under various circumstances.
