CUB on OHA Revoking Cryptosporidium Treatment Variance
Posted on May 24, 2017 by Janice Thompson
Tags, Water/Wastewater
CUB anticipated the Oregon Health Authority (OHA) revoking the Portland Water Bureau’s Cryptosporidium treatment variance because our monitoring of sampling results indicated that the allowed annual Crypto level was exceeded.
Indeed, we testified at the May 18 utility rate hearing on the likelihood of losing the treatment variance and urged a comprehensive review of treatment options.
Crypto treatment variance background
In 2012, PWB obtained a variance from the Oregon Health Authority (OHA) regarding the Environmental Protection Agency (EPA) Long Term 2 Enhanced Surface Water Treatment Rule (LT2) mandating Cryptosporidium treatment. The rationale was that the Bull Run Watershed is a highly protected area with few of the risk factors, particularly access by livestock, typically associated with Crypto related health problems. Compliance with the OHA variance, however, required observation monitoring with sampling for Crypto oocysts at least two times per week. No Crypto was detected between April 2012 and December 2016. However, enough Crypto was found between December 2016 and January 8, 2017 that demonstration monitoring, the next level of assessment required by the OHA variance, began. Given Crypto detections by March, it seemed clear that the annual amounts allowed under the variance would be exceeded.
On May 19, OHA revoked the Crypto treatment variance. The revocation effective date is no later than September 22 and requires a PWB and OHA agreement on interim measures and a compliance schedule.
Treatment options – ultraviolet and filtration
The PWB has reviewed the filtration option, but before OHA granted the Crypto treatment variance, the focus was on ultraviolet treatment. While the ultraviolet approach is less expensive, it also provides less protection compared to filtration treatment against other risks such as increased turbidity (particulates in the water) that could result from increases in duration and intensity of rainstorms and/or the effects of a major fire in the Bull Run Watershed.
CUB strongly urges a comprehensive review of treatment options. Obviously, we are interested in lower cost options, but our least cost/least risk analytical approach means a careful assessment of risk is also essential. If ultraviolet treatment provides less protection against a broader range of risks, its lower cost may be pennywise and pound foolish. Input provided by water quality and public health experts will guide CUB’s recommendations, but just because the ultraviolet option was favored in the past does not preclude the current need for a comprehensive review of all treatment options.
Crypto and public health
No Crypto has been detected since March and DNA analysis indicates that the Crypto species found in the Bull Run comes from wildlife and is not the type typically linked to human health concerns. However, the federal LT2 rule does not distinguish between different species of the Crypto parasite. PWB’s ongoing consultation with Multnomah County Health Department does not indicate a health risk, though a consistent recommendation has been that people with compromised immune systems should consult their doctor.
CUB will continue to monitor this situation and will keep our readers updated as more information becomes available.
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05/23/17 | 0 Comments | CUB on OHA Revoking Cryptosporidium Treatment Variance