8 comments
The level spreader detail was updated to be less blurry but in the process the length of level spreader changed back to 50' instead of Lls. and the Lsf was also not labeled on this version.
Comments following review of Chapter 8 of Handbook V1.1:
1) In the first sentence of 8.4.4.2, reference to 9VAC25-870-65 D of the Virginia Erosion and Stormwater Management Handbook is incorrect.
Recommendation: Change reference to 9VAC25-875-590 D.
2) The proposed table in 8.4.4.2 disincentivizes completion of robust testing by reinstituting a ceiling for TAPE GULD for TP at 50% down from the current 65% allowance. Furthermore, the language preceding the table encourages manufacturers to "shop" around for a more favorable approval from less prescriptive regulatory regimes elsewhere in the country. The former creates inconsistencies with the current approved list of filter and biofilter MTDs in Chapter 8, while the latter does not provide certainty that robust TP data will be used to justify VDEQ's TP efficiency assignment.
Recommendation: (1) Either remove the cap for systems maintaining TAPE GULD for TP since there is no prescribed cap for other state, regional, or national verification or certification programs; or (2) Include the phrase 50%-65% in the Assigned TP Removal Efficiency Colum (column 2) next to TAPE TP removal ≥ 50% and cap the highest TP % awarded for any MTD at 65%. The 2nd recommendation is consistent with DEQ's most recent MTD use guidance document, GM2021-2006, since rescinded, and the still codified 2011 filtering specification which lists MTDs as an allowable configuration while capping TP credit for all filtering practices, proprietary or non-proprietary, at 65%.
3) The phrase "when a higher efficiency is provided, the VDEQ will use the higher efficiency" immediately below the table indicates VDEQ will use a higher efficiency regardless of its origins. Not all state, regional, or national verification or certification programs evaluate phosphorus removal performance, which is VA's pollutant of concern. An approval in another state does not necessarily mean established testing protocols have even been followed, as is required by § 62.1-44. 15:28 of the Code of Virginia. No other state, regional, or national verification or certification currently maintains as robust a testing protocol as TAPE. Antiquated protocols can be used as written. Without sufficient guardrails included, the proposed language is too loosely constructed to effectively implement.
Recommendation: Rewrite sentence to: When a higher efficiency is provided by another state, regional, or national verification or certification program with a current, established testing protocol more robust or equivalent to TAPE, the VDEQ will use the higher efficiency.
4) Column 1 in the Table in 8.4.4.2 references only certification programs within V1.1. However, VDEQ has certified for use in Virginia several verified only MTDs. There is also a practice approved as "other". "Other" is also not referenced in the 8.4.4.2 Table. These practices were listed in V1.0 and were carried over to V1.1. There needs to be agreement between the basis for approval column in Table 8-1, 8-2, and 8-3 and the verification and/or certification programs used to assign TP removal efficiencies in the Table in 8.4.4.2 so as not to artificially limit competition and innovation moving forward.
Recommendation: Update Table in 8.4.4.2 to provide full transparency regarding how programs other than those currently listed can be used to meet § 62.1-44. 15:28.