Wednesday, February 10, 2010

Review of Iowa Lakes Using Proposed Water Quality Standards

The Iowa Department of Natural Resources (IDNR) has proposed a revision to the water quality standards used to assess Iowa lakes. [Read more about the proposed standards] In conjunction with this rulemaking process, IDNR has published a review of existing data sets on Iowa lakes to evaluate how well lakes in the State currently comply with the current and the proposed standards.

The report, “How Many Lakes Will Meet the New Criteria”, compares sampling data from 132 lakes with both the proposed criteria and the criteria currently used to decide whether a lake fully supports swimming. The Trophic State Index (TSI) is used to quantify whether a lake meets the narrative water quality criteria contained in Iowa’s water quality standards such as a lake must be free of nuisance aquatic life. The TSI measures water quality parameters such as nutrient concentrations, transparency and chlorophyll-a concentrations. algae blooms. These narrative criteria apply to all surface waters.

In summary, of the 132 lakes reviewed, 64% do not meet the TSI criteria. A total of 88% of these lakes do not meet the proposed criteria. Most of the lakes that do not meet the proposed criteria would not meet either the transparency or the chlorophyll-a criteria.



Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

Caltha LLP Aquatic Toxicology / WQ Standards Services Website



Monday, February 8, 2010

TCEQ Proposed Antidegradation Rule

The Texas Commission on Environmental Quality has proposed revisions to its water quality standards, including Chapter §307.5. Antidegradation. These rules apply to all wastewater discharges, including stormwater. The rule establishes the antidegradation policy of the commission which includes a three tier system:

Tier 1. Existing uses and water quality sufficient to protect those existing uses must be maintained. Categories of existing uses are the same as for designated uses
Tier 2. No activities subject to regulatory action are allowed that would cause degradation of waters that exceed fishable/swimmable quality, unless it can be shown that the lowering of water quality is necessary for important economic or social development.
Tier 3. Outstanding national resource waters are defined as high quality waters within or adjacent to national parks and wildlife refuges, state parks, wild and scenic rivers, and other designated areas of exceptional recreational or ecological significance. The quality of
outstanding national resource waters must be maintained and protected.


No discharges can lower water quality to the extent that the Texas Surface Water Quality Standards are not attained. Any discharge of wastewater that would constitute a new source or an increased source of pollution from any industrial, public, or private project or development
are required to provide a level of wastewater treatment consistent with the provisions of the
Texas Water Code and the Clean Water Act. For nonpoint sources of pollution, as necessary, cost effective and reasonable best management practices established through the Texas Water Quality Management Program are to be implemented.


Tier 1 reviews must ensure that water quality is sufficiently maintained so that existing uses are protected. All discharges that could cause an impairment of water quality are subject to Tier 1 reviews. If the existing uses and criteria of a potentially affected water body have not been previously determined, then the antidegradation review must include a preliminary determination of existing uses and criteria.

Tier 2 reviews apply to all discharges that could cause degradation of water quality where water quality exceeds levels necessary to support propagation of fish, shellfish, wildlife, and recreation in and on the water (fishable/swimmable quality). Tier 3 reviews apply to all discharges that could cause degradation of outstanding national resource waters.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

Caltha LLP Aquatic Toxicology / WQ Standards Services Website



TCEQ Nutrient Criteria and Screening Levels

The Texas Commission on Environmental Quality (TCEQ) is proposing a methodology to calculate site-specific Nutrient Criteria and Screening Levels for reservoirs, is as a new addition to the standards rule. The result will be chlorophyll a criteria and supplemental screening values for total phosphorus and transparency which will be used to confirm if a water body is attaining the nutrient criteria. TCEQ is soliciting comments on this draft approach to derivation of criteria and screening levels in comparison to other alternative criteria, such as stand-alone criteria for chlorophyll a without supplemental screening levels.

If selected as the preferred method, TCEQ intends to use a stand-alone chlorophyll a criteria that is adjusted to be equivalent to chlorophyll a criteria with supplemental screening levels. If stand-alone chlorophyll a criteria were to be adopted, then references to supplemental screening levels for total phosphorus and transparency would be omitted in draft language in §307.2, §307.7, §307.9, and §307.10, and only the statistically adjusted stand-alone chlorophyll a criteria would appear in the final methodology.

Criteria for chlorophyll a are planned to be assessed with long-term medians of sampling data. Criteria for chlorophyll a are attained when they are not exceeded by the median of monitoring data results.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

Caltha LLP Aquatic Toxicology / WQ Standards Services Website



Tuesday, February 2, 2010

New or Expanded Discharges Under ADEQ Proposed General Permit

The Arizona Department of Environmental Quality (ADEQ) recently posted an updated draft of its proposed multisector industrial stormwater discharge general permit for informal stakeholder review and input. This permit “AZPDES MSGP 2010”, once promulgated, will replace the existing industrial stormwater permit, which expired in 2005. ADEQ anticipates the MSGP to be public noticed sometime during the winter of 2010.

The permit addresses new or expanded stormwater discharges to impaired waters and to Outstanding Arizona Waters (OAW).


New Dischargers to Water Quality Impaired Waters.
A new discharger to an impaired water is not automatically eligible for coverage under the general permit. To receive authorization under the permit, the applicant shall make one of the following demonstrations and retain such data and other technical information onsite with the stormwater pollution prevention plan (SWPPP):

a. That the facility will employ measures to prevent all exposure to stormwater of the pollutant(s) for which the waterbody is impaired; or
b. That the discharge from the facility has no potential to contain the pollutants causing impairment; or
c. That the discharge is not expected to cause or contribute to an exceedance of a water quality standard. The applicant must demonstrate either: (i). The discharges are subject to stormwater control measures such that the discharges meet the applicable water quality standard at the point of discharge; or (ii). The discharges are consistent with the provisions of the TMDL.

Within 32 business days of receipt of this information, ADEQ will notify the applicant in writing that:
a. It is acceptable to proceed under the general permit;
b. The SWPPP is incomplete or otherwise deficient and must be revised; or
c. It is not eligible for coverage under the permit


Discharges to Outstanding Arizona Waters.
New or expanded discharges to a water or portion thereof classified as an OAW are not automatically eligible for coverage under the permit. To receive authorization for a new or expanded, the applicant must:

a. Submit the NOI and a copy of the SWPPP that includes a sampling and analysis plan to collect data appropriate to verify the demonstration below and
b. Demonstrate that the discharge will not degrade existing water quality in the downstream OAW.


Within 32 business days of receipt of this information, ADEQ will notify the applicant in writing that:
a. It is acceptable to proceed under the general permit;
b. The SWPPP is incomplete or otherwise deficient and must be revised; or
c. It is not eligible for coverage under the permit

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

Caltha LLP Aquatic Toxicology / WQ Standards Services Website