Total Dissolved Solids Control Measures

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Reynard Conley
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1 Total Dissolved Solids Control Measures Texas Association of Clean Water Agencies Presented by Michael G. Morrison, P.E., BCEE Water/Wastewater Manager, Central Region Freese and Nichols, Inc. 512/ July 25, 2008

2 Study Location Proposed Highway 121

3 Unique Approach Effluent Reuse System Brazos Electric

5 The Problem WWTP effluent Total Dissolved Solids (TDS) have increased in the past 10 years to levels that may preclude the City from discharging its effluent as currently permitted. The primary reason for TDS increases are: Use of supplemental groundwater with high TDS Increasing industrial discharges to POTW Aggressive direct reuse campaign

6 The Givens Stream standards Segment 1227 TDS = 500 mg/l WWTP effluent TDS average = 850 mg/l Domestic background TDS average = 379 mg/l Draft permit limits TDS = 685 mg/l Must remove 10,000 lb/day TDS

7 Receiving Waters MARTI Reservoir Marti Dam TDS=270 EAST BUFFALO CREEK Pipeline TDS=360 Wilson Street TDS=230 Mansfield TDS=310 WEST BUFFALO CREEK Henderson at Buffalo Springs TDS=810 Country Club TDS=230 Main Street TDS=330 WWTP Discharge Downstream TDS=640 BUFFALO CREEK LAKE PAT CLEBURNE Segment 1228 TDS=193* WQC=300 NOLAN RIVER Segment 1227 TDS=339* WQC=500 LAKE GRANBURY Segment 1205 TDS=1,560* WQC=2,500 BRAZOS RIVER Segment 1204 TDS=1,170* WQC=1,600 LAKE WHITNEY Segment 1203 TDS=828* WQC=1,500 BRAZOS RIVER Segment 1242 TDS=776* WQC=1,000

8 Source Identification TDS Analysis (lbs/day) Industry 6 Industry Industry 4 Industry 3 8,700 9,471 Industry 2 Industry ,462 Background 10,827 POTW 23, ,000 10,000 15,000 20,00 0 Pounds per day 25,000

9 The Solutions Integrated Approach Industrial pre-treatment controls with Class I disposal well Emerging technology Stream standards revision

10 Site Survey Results Found three candidate waste streams: Power plant cooling tower blowdown Reject stream from high purity water treatment process a chemical plant Discharge from building product manufacturer None of the candidate waste streams could be eliminated by industries

11 A New Partner Oil and gas operator proposed a Class II salt water disposal well in the industrial park City proposed a Class I well with rights to co-dispose wastewater Lease assures capacity for City to inject high TDS waste stream City pays fee per barrel for disposal

12 TDS Control Project Cleburne Lift Station

13 Economics Class I well and collection system capital cost = $2 million Capacity = 8,000 barrels/day (336,000 gpd) Disposal cost = $0.35/barrel ($1.3 million annually) Permitting required 1.5 years

14 Emerging Technology Brine (TDS) concentrator to reduce disposal cost Difficult to concentrate a solution close to its saturation index In January 2008, pilot testing of New Logic Research Vibratory Shear Enhanced Process (VSEP) membrane filtration technology was conducted for the City of Cleburne VSEP technology is a unique membrane system that uses vibration to limit the fouling/plugging of the membrane concentrator

15 Emerging Technology cont. Initial testing results had a recovery rate of approximately 75% Potentially reduce disposal cost from $1.3 million to $325,000/yr. Produced a clean permeate for re-sale

16 Pilot Testing of Vibratory Shear Enhanced Process (VSEP) on Brackish Waters for the City of Cleburne New Logic s VSEP technology for high recovery processing

17 Cleburne Pilot Testing

18 Stream Standards Revision Comparison of numeric criteria for the Nolan River and Lake Whitney SEGMENT NAME TDS (mg/l) CL (mg/l) SO 4 (mg/l) Nolan River (Segment 1227) Lake Whitney (Segment 1203) 1, Criteria for Segment 1227 was established after the development of Lake Pat Cleburne in Prior to Lake Pat Cleburne (TDS of 200 mg/l), the City relied on groundwater with a TDS ranging from 600 to 900 mg/l. The City of Cleburne s future water supply sources all have high TDS levels.

19 Stream Standards Revision cont. The City applied to TCEQ for a stream standards revision with the following augments: Annual operating cost of the disposal well is excessive (non-compelling to TCEQ). Cost of treating for TDS at the WWTP is prohibitive (non-compelling to TCEQ). Additional action is needed because the City s TDS control program is not expected to provide a complete solution to the problem and because future water supply sources are expected to increase.

20 Stream Standards Revision cont. The City evaluated a relocation of its effluent outfall to discharge directly into Lake Whitney (Segment 1203) which has higher TDS criteria. Because the Segment is effluent-dependant, this alternative would, in most years, convert the Nolan River from a perennial to intermittent flow regime. Existing aquatic ecosystem functions would be lost or seriously compromised. This was a compelling argument for TCEQ.

21 Stream Standards Revision TCEQ has granted a three-year variance for standards revision study. Testing was performed under the Clean Rivers Program. Preliminary Standards Revisions were given to the City of Cleburne for review this month (July 2008).

Plan Groundwater Procurement, Implementation and Costs, prepared for the Brazos River Authority, July 2005.

Plan Groundwater Procurement, Implementation and Costs, prepared for the Brazos River Authority, July 2005. 6 Conjunctive Use 6.1 Lake Granger Augmentation 6.1.1 Description of Option Rapid population growth and development in Williamson County require additional water supplies throughout the planning period.