Decentralized Wastewater Treatment in Texas Watersheds

Transcription

1 Decentralized Wastewater Treatment in Texas Watersheds Bruce Lesikar Texas A&M University System Overview Surface water resources Water Quality Standards Watershed Management Programs Identifying Sources Implementation Strategies Decentralized Wastewater Treatment Surface Water in Texas Resource Texas Surface Water 23 Major Water Basins Gulf of Mexico Responsibility Water Quality Constituents Page 1

2 Major River Basins of Texas Classifications Classified Segments 4 digit tracking numbers Unclassified Segments 4 digit tracking number plus a letter Water Bodies Classified and Unclassified Segments Watershed Approach to Water Quality Management -Measured and Managed Planning Data Collection Implementation Assessment and Targeting Strategy Development Page 2

3 Water Quality Standards Designated use Recreation Drinking water Aquatic life Fish Consumption Criteria necessary to attain and maintain that use Numeric Narrative Monitor and Assess Inventory Data from past 5 years Many organizations Snapshot of conditions The 303(d) List Preventative measures are not enough Subject to EPA approval Categories of Use and Attainment Category 1 Category 2 Category 3 Category 4 Category 4a Category 4b Category 4c Category 5 Category 5a Category 5b Category 5c Attaining the water quality standard and no use is threatened. Attaining some of the designated uses; no use is threatened; and insufficient or no data and info. are available to determine if remaining uses are attained or threatened. Insufficient or no data and information to determine if any designated use is attained. Standard is not supported or is threatened for one or more designated uses but does not require the development of a TMDL. TMDL has been completed and approved by EPA. Other pollution control requirements are reasonably are expected to result in the attainment of the water quality standard in the near future. Nonsupport of the water quality standard is not caused by a pollutant. Category 5 is the 303(d) List.. The water body does not meet applicable water quality standards or is threatened for one or more designated uses by one e or more pollutants. TMDL is underway, scheduled, or will be scheduled. Review of the water quality standards will be conducted before a TMDL is scheduled. Additional data and information will be collected before a TMDL is scheduled. Page 3

4 Total Maximum Daily Load Program Total Maximum Daily Load (TMDL) Amount of allowable pollutants Category 5a waters in Texas TMDLs on the increase 63 projects in projects in 2003 Must implement Subject to EPA approval TCEQ Actions TCEQ Actions to Improve the Quality of Listed Waters Number of Impairments Texas 303(d) List Year Listed Delisted Completed TMDLs TMDLs Underway Standards Analysis and Targeted Monitoring Percent of Water Assessed Percent 100% 80% 60% 40% 20% Percent of Surface Waters Assessed 8% 100% 83% 77% 100% 79% 83% 8% 11% 80% 84% 100% 80% 85% 11% 100% 0% Assessment Year River Miles Rivers, Total Miles: 191, 228 Lake Acres Lakes, Total Acres: 1,994,716 Bays, Total Square Miles: 2,393 Bay Miles Gulf of Mexico Jurisdiction: 3,879 Square Miles Gulf Miles Page 4

5 Surface Waters that Meet Standards Percent of Assessed Surface Waters Meeting Standards As a Percent of Geographic Area Percent 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 78% 68% 65% 90% 61% 61%62% 0% 80% 70% 79% 0% 74% 66% 70% *The Gulf of Mexico has been under a Year of Assessment fish consumption advisory since % Rivers Lakes Bays Gulf Sources of Contaminantion Point Source Pollution Nonpoint Source Pollution Point Source Pollution Collection and discharge from a defined point Wastewater treatment discharge Industrial waste discharges Stormwater collection systems Point sources usually monitored and regulated Easier to implement standards for point sources Page 5

6 Nonpoint Source Pollution Diffuse sources, not easy to collect or treat Excess fertilizers, herbicides and insecticides Urban runoff and energy production Sediment Salt Acid Bacteria and nutrients Onsite wastewater treatment systems Atmospheric deposition Hydromodification Controlled through design, construction, and maintenance of BMP TMDL Defined TMDL = PS-LA + NPS-LA + MOS TMDL PS-LA NPS-LA MOS = Total Maximum Daily Load = Waste Load Allocation (PS) = Load Allocation (Anthropogenic NPS + Natural Sources) = Margin of Safety (plus Margin for Growth?) Case Study: Peach Creek Segment 1803C Peach Creek (d) list, bacteria concentration 126 colonies/ 100 ml (geometric mean) and 394 colonies per 100 ml (single grab) Designated uses Aquatic Life Contact Recreation Fish Consumption Page 6

7 Land Use in the Watershed What are the Sources? Warm blooded bodies. Categories Human Livestock & Poultry Wildlife Pets Others Confined Animal Feeding Operations Segment 1803C Page 7

8 Wastewater Treatment Plants - Segment 1803C Bacterial Source Tracking (BST) Sample Collection - Know Source Page 8

9 Samples for Analysis Library of Data Source Identification Page 9

10 Source Identification Preliminary Source Identification of Ambient Water Samples from Peach Creek ERIC-PCR DATA RESULTS Page 10

11 RIBOTYPING DATA RESULTS Implementation Strategies ALL sources contribute to the total load ALL sources should share in the reduction in total load. Source identification should be used to help people understand how they contribute Achieving Equitable Allocation Among Point and Nonpoint Sources... Costs of controlling different sources can vary substantially Allocations should consider whether costs are reasonably distributed Agencies are directed to consider cost/benefit analyses of potential control actions to assist in fairly distributing control costs Responsible parties will be more likely to carry out actions needed to implement TMDLs if they feel their share of the burden was fair Page 11

12 Decentralized Wastewater Treatment Appropriate cost effective systems. Onsite Cluster Centralized Public perception Failed systems New Technologies Different from a centralized sewer Decentralized Wastewater Treatment Systems? - Rural and Exurban wastewater infrastructure -Water Quality Protection - 40%, Wastewater Infrastructure Permitting Dispersal Systems Texas Permitting System Texas Commission on Environmental Quality TCEQ, Chapter 285, 5000 gallons per day or less TCEQ, Chapter 317, Greater than 5000 gallons per day. Review the decentralized system plans Evaluation of monitoring data Enforcement Page 12

13 Decentralized Wastewater Treatment Systems Failing Septic System What is a Decentralized Wastewater Treatment System? 1. Wastewater source 2. Collection and storage 3. Pretreatment components 4. Final treatment and dispersal components Page 13

14 Evaluate the wastewater source Evaluate site Wastewater treatment Wastewater acceptance Choose a final treatment and dispersal component Choose the appropriate pretreatment system Operation and Maintenance How do we make the system work? Types of Facilities Wastewater Sources Restaurants Quick Stops Strip Malls Residences Design knowledge Technology choice Effective treatment train Wastewater Treatment at a Site Soil Type Depth Slope Restrictive layers Separation distances Page 14

15 Water Quality Monitoring / Operation and Maintenance Monitoring system performance All systems require operation and maintenance Frequency Types of activities Types of inputs O&M Registration Service Contracts Summary Surface water resources Water Quality Standards Watershed Management Programs Identifying Sources Implementation Strategies Decentralized Wastewater Treatment Page 15