LOUISIANA DEPARTMENT OF ENVIRONMENTAL QUALITY | Secretary Aurelia S. Giacometto
A DEPARTMENT OF THE STATE OF LOUISIANA
WATER SURVEYS SECTION
The Water Surveys Section was initially created as a part of the TMDL Program, sponsored by the Environmental Protection Agency (EPA). In 1972, the Clean Water Act (CWA), developed by the EPA, implemented pollution control programs such as setting water quality standards for all contaminants in surface waters. Total Maximum Daily Load (TMDL) is the amount of a pollutant a waterbody can assimilate without exceeding the established water quality standard for that pollutant. The Water Survey Section performs intensive surveys on impaired waterbodies of Louisiana, which are listed on the EPA's 303 (d) list.
During a survey on a watershed, a wide range of biological, physical, and chemical data is collected by Environmental Scientists and evaluated by DEQ's modelers. Environmental Scientists employ several methods of collecting data such as:
Assessment of data may eventually result in revisions in the water quality standards set or a delisting of a waterbody deemed to be meeting current standards.
The Water Surveys Section collaborates with LDEQ's Non-Point Source (NPS) Section to help plan and execute several water quality projects through field data assessment and sample collection. Section 319 of the Clean Water Act required that the states develop a plan to reduce and control various types of NPS pollution, which comes in the form of agriculture and urban runoff, home sewage systems and other sources. Water Surveys is tasked with reconnaissance of accessible and representative sites for each project, as well as adhering to monthly or bi-monthly water sample and flow measurement collection schedules. Their efforts provide a qualitative and quantitative assessment of a waterbody and help identify potential "hotspots" for non-point source pollution. With the help of the Louisiana Department of Agriculture and Forestry (LDAF) and the United States Department of Agriculture-Natural Resource Conservation Servce (USDA-NRCS) and the implementation of Best Management Practices (BMPs), LDEQ is hoping to educate local entities of how their land use practices can adversely affect local waterbodies.
2012
Bayou Chene - NP2012014 - Bayou Chene is listed as impaired for not meeting its designated use for fish and wildlife propagation (FWP) due to low dissolved oxygen concentrations stemming from numerous agricultural practices. Irrigation of rice and other crops are considered by LDEQ to have a significant impact on water quality in this area. Fecal coliform (FC) is the suspected cause of impairment for primary contact recreation (PCR), due to runoff from forest/grassland/parkland, drought related impacts, and rural (residential areas). Water quality data continues to be collected to pinpoint additional critical areas where future BMPs may be implemented.
2013
Bayou Queue de Tortue - NP2013001 - Bayou Queue de Tortue is fully meeting primary and secondary contact recreation uses but is impaired for fish and wildlife propagation because of high concentrations of nutrients, total suspended and dissolved solids, low dissolved oxygen, turbidity and mercury in fish. Agricultural practices are the suspected sources. As BMPs continue to be implemented, it is expected that dissolved oxygen concentrations will increase, and nutrients, total dissolved solids (TDS), and turbidity concentrations will decrease.
Comite River - NP2013010 - Comite River was selected by LDEQ and partners as one of Louisiana’s priority waterbodies to partially and/or fully restore by October 2027. Louisiana’s 2024 Integrated Report (IR) indicates that the subsegment is impaired for primary contact recreation (PCR) because of FC. Suspected sources of these impairments are on-site sewage treatment and disposal systems (OSDS) and sanitary sewer overflows. Currently, long-term monitoring for FC and field parameters occurs at one site to track water quality changes while education/outreach activities, including home system inspections, are ongoing.
2015
Bayou Mallet – NP2015001 – Louisiana’s 2020 Integrated Report indicated that Bayou Mallet was not supporting its designated uses for FWP and PCR. The suspected causes of the FWP impairment are low concentrations of dissolved oxygen (DO) and high concentrations of TDS. The suspected cause of the PCR impairment is high levels of FC. The impact of BMP implementation in the critical areas are being monitored by LDEQ via sampling downstream.
Big Creek North - NP2015002 - Louisiana's 2016 Integrated Report indicated that Big Creek was not supporting its designated use for (FWP); however, it was fully meeting SCR and PCR uses. The suspected cause of NPS impairment is turbidity from agricultural practices. BMPs have been implemented and two more have been added to Big Creek's headwaters to improve water quality further downstream as of August 2024.
Bayou des Cannes - NP2015003 - Louisiana's 2024 Integrated Report indicated the bayou was not supporting its designated use for (FWP); however, it was fully meeting SCR and PCR uses. Suspected causes of impairment include nitrate-nitrite, low dissolved oxygen, total phosphorus, and turbidity, due to agricultural and natural sources. BMPs to be implemented include irrigation land leveling, grade stabilization structures, residue management, irrigation water management/dry seeding of rice, and shallow water for wildlife.
2016
Hemphill Creek - NP2016002 - Louisiana's 2022 Integrated Report indicated that Hemphill Creek was not meeting its PCR designated use due to high concentrations of fecal coliform. The suspected sources include livestock and sewage discharge in unsewered areas. Since partnering with LDAF, LDEQ will continue long-term monitoring in conjunction with LDAF's implementation of BMPs. The addition of nutrient data will inform LDEQ's nutrient management strategy group of the state of nutrients in this watershed and will support the fecal coliform data by providing valuable information about the overall health of the watershed.
Bayou Vermilion - NP2016003 - According to the 2022 Integrated Report, Vermilion River is impaired for (FWP) with suspected causes of nitrate-nitrite and dissolved xxygen. It is also impaired for PCR and SCR with a suspected cause of FC. The suspected sources for the FWP impairment of dissolved oxygen are agriculture and natural sources while the suspected causes for nitrate-nitrite are unknown. The Bayou Vermilion District (BVD) initiated the individual on-site waste disposal system (OSDS) inspection program in the Coulee Mine in July 2017. LDEQ Water Surveys initiated water quality monitoring from June 2016 through June 2017, establishing a baseline for Fecal Coliform. The overall intent of the inspection program is to improve the water quality of the Vermilion River within the urbanized and rural areas of Lafayette Parish by reducing or eliminating the effects of malfunctioning OSDSs in the area. This will be accomplished through continued public education and awareness campaign demonstrating maintenance of home sewage systems through OSDS inspections. To further support BMP implementation, LDEQ samples many sites throughout the subsegment to help detect water quality changes in the area.
2017
Bayou du Portage - NP2017002 - During LDEQ's ambient water quality monitoring of a site located on Bayou Portage, data collected indicated that dissolved oxygen, turbidity, and fecal coliforms violated the state's standards for FWP and PCR. Agriculture practices dominated by surgarcane, pasture, rice and aquaculture are suspected contributors. Reducing erosion and runoff from agricultural lands, pasture, and streambanks are expected impacts from implementation of BMPs
2018
Bayou Grosse Tete - NP2018001 - Bayou Grosse Tete is listed as impaired for FWP with suspected causes of dissolved oxygen, nitrate-nitrite, and total phosphorus from agriculture runoff. TDS and FC are also issues at sites throughout the subsegment. On-site sewage treament systems in the area are a suspected source of FC. Water quality monitoring thoughout the subsegment will be useful to identify areas with high pollutant loading and help target mitigation measures.
Bayou Maringouin - NP2018002 - Since 1996, Bayou Maringouin has periodically been identified on the Louisiana Water Quality Integrated Report (IR) as not meeting PCR and FWP designated uses due to high bacteria, nutrients, pesticides, TDS, and/or low dissolved oxygen. As reported in the 2022 and 2024 IRs, TDS, DO and FC continue to be listed as causes of impairments. OSDS sites are the suspected source of high FC bacteria and low DO. LDEQ identified agriculture and silviculture as primary sources for the TDS impairment. The BMPs will target sediment, nutrients, and bacteria. Reducing erosion and runoff from agricultural lands, pasture, and streambanks are expected impacts from implementation of BMPs.
2021
Bayou Bartholomew – NP2021001 – LDEQ’s 2022 IR currently indicates the waterbody is PCR and SCR; however, it is not fully supporting its FWP and outstanding natural resource (ONR) uses. The NPS suspected cause of impairment is turbidity, due to agriculture. Pollution reduction measures are being identified by key stakeholders (LDEQ, LDAF, and NRCS) and are being selected to reduce the runoff causing the water quality impairments.
2022
Bayou Courtableau – NP2022001 – According to the 2024 IR, Bayou Courtableau was impaired for the designated use of FWP with suspected causes of DO and turbidity. The suspected source is agriculture. LDEQ’s monitoring effort will provide a quantitative understanding of existing water quality conditions throughout the bayou, knowledge of where high sediment concentrations occur, and measurement of improvements in water quality conditions following BMP implementation.
Lake St. Joseph – NP2022002 – According to the 2024 IR, Lake St. Joseph was not supporting its FWP use and PCR use. Low DO along with high concentrations of nutrients and turbidity were suspected causes of impairment for FWP use. High nutrient levels are linked to low DO concentrations. The PCR impairment was due to high concentrations of FC. LDEQ monitoring data will be used to strategically target NPS loadings into the lake to improve overall watershed health and restore use support.
NEW VISION PROJECTS - CLEAN WATER ACT SECTION 303(D)
2019
Natalbany River – ES2019001 – Louisiana’s 2024 IR indicated that Natalbany River is impaired for FWP because of low levels of DO and high levels of mercury. Suspected sources of these impairments are OSDSs and sanitary sewer overflows. To maintain healthy waters and assure long-lasting water quality, LDEQ continues to monitor this subsegment for FC as OSDS inspections and homeowner education is ongoing.
2020
New River – ES2020001 – New River has been targeted for the development of a TMDL alternative plan. Water Surveys will survey the stream as prescribed in the sample plan, in order to retrieve data that will satisfy the scope of the TMDL alternative plan.
2021
Blind River – ES2021001 – Blind River has been targeted for the development of a TMDL alternative plan. Water Surveys will survey the stream as prescribed in the sample plan, in order to retrieve data that will satisfy the scope of the TMDL alternative plan.
For information on LDEQ's Long-Term Vision for Assessment, Restoration, and Protection Program, click here.
WATER STANDARDS AND ASSESSMENT PROJECTS
2020
Cyanobacteria Harmful Algal Bloom (CyanoHAB) Detection and Verification Pilot Study – WQ2020005 – Starting in the spring of 2021, LDEQ Water Surveys, in a cooperative effort with the Water Quality Standards and Assessment Section, began monitoring for CyanoHABs in a multi-regions, multi-lake survey where CyAN satellite imagery showed bloom activity. Three areas in coastal southeast Louisiana were identified as priority regions based on previous review of CyAN imagery products between 2017 and 2020: east of the Mississippi River (Lake Maurepas and Lake Pontchartrain), west of the Mississippi River (Lac des Allemands, Lake Salvador, Lake Verret, and Lake Palourde), and coastal areas in Breton and Barataria bays. Monitoring efforts include water quality field and laboratory measurements (including cyanotoxins, nutrients, and pigment analysis) and total algal and cyanobacteria speciation and enumeration. EPA recommends monitoring for two common and well-studied toxins associated with CyanoHABs, Microsystins and Cylindrospermopsin. Completed August 2023.
2021
Pesticides – WQ2021002 – According to the 2020 IR, there are waterbodies throughout the state considered impaired for pesticides. The subsegments are not meeting the designated use of FWP. All have agriculture as the suspected source. Water quality monitoring is necessary to demonstrate attainment or continued impairment for water quality assessment purposes. Completed August 2023.
Clean Metals – WQ2021001 – According to the 2020 IR, there are waterbodies throughout the state considered impaired for copper or lead metals. The Clean Water Act required states to adopt numeric criteria for toxic pollutants when the discharge or presence of those toxic pollutants could reasonably be expected to interfere with designated uses. The subsegments are assessed for copper or lead based on hardness-dependent freshwater and marine metals criteria, additional measurements to support assessments include field parameters and hardness concentrations for criteria calculations and assessment determinations. Completed June 2024.
Video courtesy of Smith-Root
Evaluation of Dissolved Oxygen in Inland Rivers and Streams within Louisiana's Southern Plains Terrace and Flatwoods (SPTF) Ecoregion - DEQ is conducting a Use Attainability Analysis (UAA) in the SPTF ecoregion to determine appropriate water quality criteria to support the fish and wildlife propagation designated use.
An ecoregion is a relatively homogeneous area of similar ecological characteristics such as:
Because of the similarity and homogeneity of ecological characteristics within an ecoregion, an ecoregional approach provides a framework for determining appropriate water quality standards by water body type on a regional basis.
Data collected at designated reference sites in the SPTF ecoregion will help develop ecoregion-wide dissolved oxygen criteria.
Nutrient Gradient Inland Lakes Project (NGIL)
During the summers of 2019-2022 the Louisiana Department of Environmental Quality (LDEQ) is conducting a study of nutrients and aquatic life in Louisiana’s inland, freshwater lakes. A total of 48 lakes, ponds, and reservoirs across four of the state’s inland ecoregions in central and northern Louisiana are planned to be sampled. Field crews will be using boats and hand-held equipment to collect water quality data; habitat characteristics; and biological communities including zooplankton, benthic macroinvertebrates, diatoms and algae, and fish.
For further details about this study, please see the U.S. Environmental Protection Agency approved Quality Assurance Project Plan (QAPP) 3070: