7 Del. Admin. Code § 7103-80.0

Current through Register Vol. 28, No. 3, September 1, 2024

Section 7103-80.0 - Monitoring Requirements

80.1 General

80.1.1 There are at least two objectives for a monitoring program at a land application site. The first is to satisfy the permit requirements set by the Department. The second objective is to provide the data necessary to optimize the system's operation. The data to meet the second objective may or may not be the same as that required by the permit. The facility's Plan of Operation and Management shall address the data needs for optimum plant operation.

80.1.2 The sampling and analysis methods used for wastewater and groundwater must be in accordance with the most recent issue of Standard Methods for Examination of Water and Wastewater" published jointly by the American Public Health Association, the American Water Works Association and the Water Pollution Control Federation, and Methods for Chemical Analysis of Water and Wastes" published by the United States Environmental Protection Agency. Soil chemical testing must be in accordance with the Methods of Soil Analysis" published by the American Society of Agronomy. Other methods, properly documented by the applicant, may be utilized upon approval by the Department.

80.2 Preapplication Treatment Facility and Storage Pond(s)

80.2.1 Influent to the preapplication treatment system and treated effluent applied to the spray fields must be monitored. Parameters which may require monitoring under the system's permit include: influent flow, volume of water applied to the spray fields, BOD (influent and effluent), suspended solids (influent and effluent), fecal coliform bacteria, pH (influent and effluent), COD, TOC, ammonia nitrogen, nitrate nitrogen, total Kjeldahl nitrogen, total phosphorus, chloride, Na, K, Ca, Mg, metals, and priority pollutants. The parameters included in the permit monitoring requirements and the sampling frequency for those parameters will be determined on a case by case basis and will be dependent on site conditions. The designer shall propose a monitoring program based on preapplication facility and land treatment system management; emphasis shall be placed on those constituents identified as land limiting.

80.3 Groundwater

80.3.1 A system is required for monitoring the quality of groundwaters influenced by the slow rate land treatment system. These regulations require the operation of systems that will function according to their performance criteria without causing the State's groundwater resources to violate State or Federal Drinking Water Standards on an average annual basis.

80.3.2 The placement and screened interval of monitoring wells shall be determined based upon site specific hydrogeology.Minimum monitoring well requirements are as follows:

80.3.3 One well upgradient or otherwise outside the influence of the land treatment site for background monitoring.

80.3.4 One well within the wetted field area of each drainage basin intersected by the land treatment site.

80.3.5 Two wells downgradient of the wetted field area in each drainage basin intersected by the land treatment site.

80.3.6 One well upgradient and one well downgradient of the pond treatment and storage facilities in each drainage basin intersected by the land treatment site.

80.3.7 Monitoring wells must be constructed in accordance with the Department's "Guidelines for the Construction of Monitoring Wells". Protective casings or other barriers must be located around all monitor wells to protect them from damage by farm equipment or other vehicles. In addition, all monitor wells must be labeled as indicated in the design plans.

80.3.8 The Division's Water Supply Branch must be consulted for the design and construction of groundwater monitoring wells at slow rate land treatment sites. Permits are required for the installation of these wells.

80.3.9 Sampling of the groundwater under the LTS permit must be performed according to the Department's "Manual for Groundwater Sampling" or other Department-approved procedure and may require measurement of one or more of the following parameters: depth to groundwater, pH, COD, TOC, nitrate nitrogen, total phosphorus, electrical conductivity, chloride, fecal coliform bacteria, metals and priority pollutants. The parameters included in the permit monitoring requirements and the sampling frequency for those parameters will be determined on a case by case basis and will be dependent on site conditions. The permittee will be required to submit groundwater quality and water table elevation data on a periodic basis. The Department also encourages the installation and monitoring of soil water lysimeters within the wetted field area. These are useful as trend monitoring devices to identify problems before the groundwater system is affected.

80.4 Surface Water and Drainage Systems

80.4.1 When a perennial stream traverses or lies at the boundary of a slow rate land treatment site, water quality monitoring of this stream may be required. The parameters and frequency of monitoring will be specified as a special condition in the facility's LTS Permit. Sampling upstream and downstream of the wetted field area as well as flow measurement may be required.

80.4.2 As discussed in Subsection 75.0, land treatment systems incorporating drainage improvements that result in a point discharge to surface waters must obtain a National Pollutant Discharge Elimination System (NPDES) Permit. In addition to requiring a Plan of Operation and Management, the NPDES Permit will include effluent limits, monitoring parameters, and sampling frequencies for the drainage system. The intent of this monitoring is to insure complete renovation of the irrigated wastewater before discharge.

80.5 Soil

80.5.1 Representative soil samples from each major soil series within the wetted field area must be taken and analyzed according to the schedule in Table 402-1. Soil pH is an indicator of changes in soil chemistry. If soil pH remains constant, analysis of cation exchange capacity and percent base saturation is not required. If the soil pH changes by one unit, analysis of these parameters shall be required.

80.5.2 Wastewater irrigation systems receiving industrial process wastes may be required to monitor metals and priority pollutants in site soils and possibly vegetation. The parameters and frequencies will be determined on a case-by-case basis.

80.6 Rainfall and Climatic Data

80.6.1 Monitoring of daily rainfall and temperature at the land application site may be required depending on the criticalness of these factors to system management. Antecedent rainfall and soil moisture conditions can be correlated to provide an operating scheme for the wastewater irrigation system. Monitoring of wind speed and direction may also be required.

80.7 Table 402-1 MONITORING REQUIREMENTS, SOIL^a

Parameter	Sampling Frequency
pH	Once per yea
Cation Exchange Capacity	If pH changesd
Percent Base Saturation	If pH changesd
Phosphorus Adsorption^b	Once every 4 years
Metals and Priority Pollutants	Once per year

80.7.1^aComposite soil samples representing each soil series within spray fields. Soil samples should be taken at 15 to 30 inches depth. A minimum of one composite sample for every 10 to 20 acres of each soil series is required.

80.7.2^bAt sites receiving high phosphorus loadings where percolate is likely to flow to a sensitive surface water, sampling frequencies will be determined on a case-by-case basis.

80.7.3^cFor facilities receiving significant quantities of metals or priority pollutants, this analyses is required. For other facilities, frequency to be set on a case-by-case basis.

80.7.4^dMore than one standard unit from pH of soil prior to the application of wastes.

7 Del. Admin. Code § 7103-80.0