Summary of Variance Examples_9-28-09_for RWG

Variance "Type": Individual variance issued to Central and Camelback Groundwater Treatment System Facility. The facility is extracting groundwater contaminated with tetrachloroethene (PCE) and BTEX and treating with granulated activated carbon units prior to discharge.

Pollutants: Boron (1,000 ug/L criterion associated with an Agricultural Designated Use)

40 CFR § 131.10(g)(1) - Naturally occurring pollutant concentrations prevent the attainment of the use. The facility operations do not contribute to the concentrations of boron naturally present in the source groundwater and receiving water.

Maintain current discharge levels of boron during the term of the variance (<1300 ug/L).

September 28, 2007	Arizona DEQ submits a request for the variance with supporting rationale to EPA.
November 19, 2007	EPA reviewed the request along with the associated draft permit that included a variance for boron and provided a preliminary approval of the variance, subject to public comment and review.
February 14, 2008	EPA approves the variance request.

Variance "Type": Waterbody variance (referred to as a “temporary modification” in Colorado). Several POTWs discharge to the waterbody.

Applicable Waterbody: Monument Creek downstream of the Tri-Lakes Wastewater Treatment Facility

Section 31.7(3)(a)(iii) of Colorado’s Basic Standards and Methodologies for Surface Waters (Basic Standards), authorizes temporary modifications where there is “significant uncertainty” regarding the appropriate long-term underlying standard. So, in this example, the Colorado Water Quality Control Commission adopted a temporary modification when results from the first two rounds of a water effects ratio (WER) study for copper indicated that development of site-specific aquatic life criteria for copper was justified. The temporary modification provides time for completion of the site-specific study.

During the period of the temporary modification, acute and chronic criteria of 36.4 ug/L and 24.8 ug/L, respectively, apply to Monument Creek downstream of the Tri-Lakes Wastewater Treatment Facility. These interim criteria are equal to application of a WER of approximately 2 to the underlying criteria, which is conservative given that WERs of >5.2 and 7.3 were calculated in the first two rounds of WER testing.

November 9, 2004	Colorado Water Quality Control Commission adopts the temporary modification.
November 24, 2004	EPA receives Colorado’s submission requesting approval of the temporary modification.
January 2005 (approx. date)	EPA approves Colorado’s request for a temporary modification.

Pollutants: Cadmium, lead, and zinc (criteria associated with aquatic life designated use)

40 CFR § 131.10(g)(6) - Controls more stringent than those required by sections 301(b) and 306 of the Act would result in substantial and widespread economic and social impact

Maintain current discharge levels during the term of the variance while working towards implementation of measures which will reduce metal concentrations over time. Specific requirements related to inflow and infiltration work and investigating treatment options included in the NPDES permits.

2001	Original exchanges between facilities and EPA pertaining to the need for and economic analysis conducted to support issuance of a variance.
August 2002-January 2003	EPA issues public notice for the variances and the draft permits incorporating the variances.
August 1, 2004	EPA incorporates variances into NPDES permits for the three facilities with a variance effective date of August 1, 2004, and expiration date of August 1, 2009.

January 30, 2009/ February 19, 2009	Idaho DEQ receives requests for variance renewals from the three facilities originally granted variances.
April 1, 2009	Idaho DEQ publishes a notice of the public comment period and public hearing on its tentative determination to grant variances for these three facilities (i.e., variance renewals).
April 22, 2009	Idaho DEQ holds a public hearing on its tentative determination.
May 1, 2009	Public comment period closes.
June 12, 2009	EPA receives Idaho DEQ's WQS submission for the three variance renewals.
July 22, 2009	EPA approves the variance renewals.

Variance "Type": Multiple discharger variance (MDV) (may include either municipal or industrial permits)

Pollutants: Mercury (1.3 ng/L criterion associated with wildlife designated use)

40 CFR § 131.10(g)(6) - Controls more stringent than those required by sections 301(b) and 306 of the Act would result in substantial and widespread economic and social impact

For reissuance of permits with reasonable potential and existing mercury limits:

• The mercury permit limit will be set at the facility-specific LCA (using MI’s mercury LCA calculation procedures) for the life of the permit.

• Require a mercury pollutant minimization plan for the duration of the permit so that reasonable progress is made toward attaining the water quality standard.

• Use of a LCA that is calculated using some procedure other than MI’s mercury LCA calculation procedures will be evaluated by MDEQ on a case-by-case basis and submitted to EPA for review and approval.

For reissuance of permits with reasonable potential but without previous mercury limits:

• Set the mercury permit limit at the facility-specific LCA (using MI’s mercury LCA calculation procedures) effective at Year 3 (allow 2 years of monitoring before the limit takes effect).

• Require a mercury pollutant minimization plan for the duration of the permit so that reasonable progress is made toward attaining the WQS.

For reissuance of permits with insufficient data for mercury limit determination:

• Require monthly monitoring with Method 1631 to start at permit issuance and continue for the permit duration.

• Include a Special Condition that triggers a mercury pollutant minimization plan if the monitoring data after one year indicates the presence of mercury at levels indicating reasonable potential to cause or contribute to exceedances of water quality standards.

• Evaluate the need for a permit modification to include a mercury limit, or include a mercury limit at the time of permit reissuance, if reasonable potential exists.

February 18, 2000	Michigan DEQ submitted its Mercury Permitting Strategy, which incorporated a MDV for mercury, to EPA. The Strategy (applicable from 2000-2004) incorporated an interim level currently achievable (LCA) of 30 ng/L.
May 24, 2002	EPA approves MDV.

May 18, 2004	Michigan DEQ submitted its revised Mercury Permitting Strategy, which incorporated a MDV for mercury, to EPA. The revised Strategy (applicable from 2005-2009) incorporated an interim LCA of 10 ng/L.
June 29, 2004	EPA approves the MDV.
2004-2007	EPA’s approval of the variance, particularly the uniform LCA of 10 ng/L, was challenged in federal court.
November 30, 2007	A settlement agreement in regards to the above-noted challenge was reached.
September 5, 2008	Michigan DEQ submits a revised procedure for calculating LCAs to EPA which replaced a component of the previously approved mercury MDV that established a statewide LCA of 10 ng/L.
September 30, 2008	EPA approves the methodology submitted to EPA on September 5, 2008, that Michigan will use to develop LCAs.

Variance "Type": Individual variance issued to a municipal facility (City of Mount Pleasant)

Variances in Texas are provided when scientific information indicates that a site-specific standards adjustment is justified (see TX WQS at 30 TAC 307.2(d)(4)). So, in this example, the Texas Commission on Environmental Quality (TCEQ) granted a variance when results from the first round of a water effects ratio (WER) test for copper indicated that development of site-specific aquatic life criteria for copper was justified. The variance provides time for completion of the site-specific study.

Any limits and monitoring/reporting requirements for the pollutant established under the previous permit are carried over into the new permit under the variance. Biomonitoring requirements are also included, as well as conditions to complete the associated site-specific criteria study, and a re-opener clause.

December 14, 2005	Variance request submitted to TCEQ.
December 16, 2006	Internal TCEQ memo from WQS coordinator to NPDES permit writer recommending that the variance be granted.
January 10, 2006	Public notice for draft permit and variance is issued.
March 10, 2006	TCEQ submits request for approval of the variance from EPA.
April 4, 2006	EPA approves the variance (note – no effect determination made under ESA in this case)
Post April 4, 2006	Final NPDES permit issued

Variance "Type": Individual variance issued to an industrial facility (Union Carbide Corporation).

Pollutants: Chloride (criteria associated with aquatic life, recreation, and public water supply uses)

Applicable Waterbody: Entire length of Ward Hollow (approximately one mile) to where it enters Davis Creek

To show that high chloride concentrations are naturally occurring in the Ward Hollow area, West Virginia and Union Carbide provided documentation showing that there are naturally occurring salt springs and deposits in the area.

July 26, 2006	EPA receives the West Virginia Department of Environmental Protection’s submission requesting approval of the variance.
September 26, 2006	EPA approves the variance request.

July 31, 2008	West Virginia Department of Environmental Protection submits a request to EPA for approval of a variance renewal.
September 8, 2009	EPA approves the variance renewal request.