Texas Waste Water Treatment Ch#04 Industrial Waste Monitoring

The National Pretreatment Program of the EPA protects publicly-owned treatment works (POTWs) and the environment from hazardous or toxic wastes discharged into a collection system.

A pretreatment program prevents the following four problems: • POTW operation interference • Chemical exposure to workers • Sludge contamination • Effluent pollutants

Pretreatment regulations, Title 40 Code of Federal Regulations Part 403 (40 CFR 403), require POTWs with flow greater than 5 MGD and/or that receive industrial waste to establish an industrial pretreatment program as a permit condition.

40 CFR 403.5(b) prohibits the discharge of pollutants that create a fire or explosion hazard, have a pH < 5.0, obstruct flow, upset treatment (shock load) or violate the permit (cause interference or pass through), raise wastewater temperature entering treatment plant > 104 °F, raise wastewater temperature entering collection system > 150 °F, are petroleum, cutting oil, or mineral oil products (cause interference or pass through), are pollutants that cause worker health and safety problems, or are hauled away except to points designated by the POTW.

A pretreatment program comprises six general elements including an industrial waste survey, establishment of legal authority, technically based local limits, standard operating procedures, monitoring, and resources/funding.

Program success depends on four types of monitoring: • Scheduled—Sampling and inspection of industries according to a schedule. • Unscheduled—Spot checks industrial sources—a federal requirement • Demand—Response to a known or suspected violation discovered in a self-monitoring report, a routine sampling trip, or by public complaint • Self-monitoring—POTW can require industry to do their own analysis and have the results sent to the POTW; perform scheduled and unscheduled monitoring to verify industry reports.

A user charge system is an equitable method for recovering pretreatment costs. Developing such a system involves these steps: 1. Estimating program costs 2. Designing a cost system 3. Calculating the charge

Industries such as refineries, food processors, dairies, paper mills, metal plating, and slaughter houses may contribute shock loads to the treatment plant. Some industries, such as refineries, paper mills, and metal platers, produce acid and alkali wastes, which cause corrosion, damage pumps, disrupt treatment, and can be hazardous to personnel. Industrial waste varies with the industry. Some wastes are not hazardous to human health but may change domestic wastewater characteristics. Some wastes are hazardous due to gas generation; others have a toxic effect on plant treatment.

gasoline is a fire hazard, cyanide is highly toxic, and sulfides tend to be corrosive in water.

Hazardous Waste: • Cyanide • Sulfides • Organics • Gasoline

The two types of samples are grab sample and composite sample. Grab Sample - A grab sample is collected within a certain time interval (not to exceed 15 minutes) and sampling location. The entire sample is collected at one time. Grab sampling is used to evaluate pollutants that cannot be held for an extended time period, such as cyanide, phenol, oil and greases, and volatile organics. Also, grab samples are used when conditions are not appropriate for composite sampling. Composite Sample - A composite sample is a mixture of individual samples collected at the same location and mixed together. Time or volume between samples may vary. In most cases, a composite sample is most representative.

Samples begin to deteriorate as soon as they are grabbed. It is important to preserve the samples, so that test results will reflect the wastewater condition at the time of sampling.

Sampling tools and containers must be clean to ensure safety and representative samples..

The synergistic effect refers to a chemical reaction that may take place when certain waste streams combine that can produce hazardous gasses that collect in manholes and lift stations.

A typical “Wastewater System Use Ordinance” has many provisions, which are summarized under the following headings: Section 1: Purpose and Scope - One purpose is to ensure maximum use of the POTW by regulation of construction, system use, and wastewater discharges. Another purpose is to fairly divide POTW costs among the users. The ordinance applies to everyone in the city limits and to other POTW users. Section 2: Terms and Definitions - Included terms are combined sewer, industrial user classes, owner, pretreatment standard, storm sewer, surface water, toxics, and wastewater facility. Section 3: Enforcement - This section sets procedures for inspections, violation notices, violation penalties, and fees. Section 4: POTW Use - This section requires connection at owner’s expense to the wastewater system of houses, buildings, properties or other facilities with toilets or other liquid waste unless a state or federal discharge permit is secured for the facility. Section 5: Private Wastewater Disposal Requirements - Where public wastewater facilities are not available, private wastewater disposal systems are required at the owner's expense. Private disposal facilities (such as septic tanks) must meet state or local design, location, construction, and operating requirements. Construction and operating permits are required for private disposal systems. When public facilities become available, connection is required within a specified period. Section 6: Building Sewers and Connections - No person may connect to the collection or storm sewer without a permit. Connections for Class I residential, Class II commercial, and Class III industrial and storm water must have a permit and pay inspection and connection fees. Every building must have a wastewater line built to building and plumbing codes. Connections of roof, foundation, parking lot, ground water or surface water drains to the sanitary system are prohibited. Section 7: POTW Use Conditions - Storm water, surface water, ground water, roof runoff, subsurface drainage or other similar water cannot be discharged to the POTW collection system. Discharge of waste that causes obstructions, physical damage, or hazardous or toxic conditions is restricted. Industries must comply with categorical pretreatment standards set by the EPA. There are limits on discharge of oil and grease, metals, toxins, corrosives and phenols. Also, slug loads, excessive solids, and excessive oxygen consumers are limited. Section 8: Industrial Discharge Requirements - Class III industrial dischargers must inform the public of the nature and quantity of their discharges. Industries must provide sampling and flow measurement and routinely test the characteristics of their discharge according to standard methods. Monitoring for pretreatment compliance and wastewater characteristics is performed at a frequency according to flow rate at industry's expense. If industry discharge damages the POTW, repair costs are paid by the industry. Section 9: Pretreatment and Surcharges - Owners must operate pretreatment and flow equalization facilities. Waste containing material harmful to the POTW, processes, equipment, or receiving waters may be required to do the following: • Pre-treat • Control quantity • Pay surcharges • Dispose by other means Section 10: Cost Recovery - This section requires user fees by persons connected to the collection system. The fees are based on measurement and analysis of each discharge. Where this is impractical, the fee is based on water consumption. Residential fees are based on water consumption. Commercial and industrial fees are based on flow and sample results. Surcharges are required for excessive organics or solids.