1. Water Quality  2. Water Discharge  3. Permit Limits
4. Water Permits  5. Treatment Systems 6. Key Questions

1. Water Quality Concepts and Standards

The concept underlying almost all regulations and  standards related to the quality of surface waters in Connecticut is that  they should be swimmable and fishable. A lot of progress has been made here as  well as nationally since the Connecticut and federal Clean Water Acts. Most  stretches of the Willimantic, Pequabuck, Farmington and Connecticut Rivers that  were once seriously polluted have now been cleaned up. Industrial dischargers  are no longer a major cause of degradation of water quality in most streams.

The concept underlying almost all regulations and standards related to the  quality of groundwater in Connecticut is that water from a well should be  drinkable without treatment in GA areas, and that there should be no degradation  of groundwater in GB areas (these are groundwater quality classifications).  Progress has been made here as well as nationally since the Clean Water Acts and  the Safe Drinking Water Act, but in heavily industrialized areas of the state  historical leaks of contaminants to the ground continue to be a problem.

Surface Water Quality Standards
The Connecticut Department of Environmental Protection (DEP) has published a  set of surface water quality standards. These standards describe ecological,  aesthetic and usage criteria for surface water bodies. Of more direct interest  to the industrial or commercial sector, the standards also set out numerical  criteria for allowable concentrations of contaminants. These concentrations are  based both on aquatic ecology considerations (health of aquatic organisms) and  on human exposure considerations (swimming, ingesting, eating fish). Surface  waters are designated AA, A, B, C or D, with AA being a drinking water reservoir  and D being heavily polluted. Coastal or brackish waters are designated SA, SB,  SC or SD, same concept. The DEP has new GIS-based water quality maps, which show  the designations along each drainage basin in Connecticut.

The other set of standards of interest to the commercial/industrial community  is the surface water  protection criteria that are part of the Connecticut Remediation Standards  Regulations (RSRs). These regulations were developed in early 1996 , and set  standards for the cleanup of contaminated groundwater that is migrating into a  surface water body (stream, lake or wetland). In many parts of the state,  groundwater recharges streams and rivers; that is, the water table in the ground  near the stream is higher than the level in the stream. This is common in the  summer and fall. Contaminated groundwater typically will leach out through the  bank into the stream, and this may create an ecological problem or human health  exposure. To prevent this, the RSRs set standards for the cleanup of  contaminated groundwater to levels that won't create a problem when the  groundwater reaches the stream.

Groundwater Quality Standards
The federal Environmental Protection Agency (EPA) has developed national  primary and secondary drinking water standards, setting (among other things) maximum contaminant levels (MCLs) for drinking water supplies, either  surface waters (reservoirs) or groundwater (wells). In Connecticut, the  Department of Health Services (DHS) has set drinking water standards. For most  contaminants, these standards parallel the federal MCLs. The DEP has published a  set of groundwater quality standards. Areas of the state are designated GAA, GA,  GB, or GC, with GAA being a drinking water supply wellfield and GC being heavily  polluted and/or suitable for waste disposal. The DEP has new GIS-based water  quality maps, which show the GAA, GB and GC designations for lands around those  groundwaters. Most (better than 90%) of the state is designated GA, and the  groundwater is presumed to be drinkable without treatment.

The other set of standards of interest to the commercial/industrial community  is the groundwater  protection criteria that are part of the Connecticut Remediation Standards  Regulations (RSRs). These 1996 regulations set standards for the cleanup of  contaminated groundwater that could be drawn into a public or private drinking  water well. They apply in GA or GAA areas, where the groundwater is presumed  okay to drink without treatment. They do not apply in GB or GC areas, which are  known to be contaminated, and which generally are served by public water supply  rather than wells. The numerical groundwater protection criteria are generally  the same as the DHS drinking water standards or the EPA MCLs. (But note that  these numerical criteria are not the entire story; the cleanup target is zero  contamination for previously uncontaminated areas, and "background" for areas  that have had some previous contamination.)

DHS programs and DEP programs are for the most part complementary, although  in certain contamination situations affecting public (and sometimes private)  drinking water supplies there is some crossover. The best thing to do in  crossover situations is to keep both agencies apprised of developments.

The Connecticut Aquifer Protection Area Program may impose operating criteria  or best management practices (which are not numerical standards) on facilities  located within an aquifer protection area. An aquifer (from the Latin aqua  (water) plus ferre (to carry)) is a geologic formation consisting of well-sorted  sands and gravels that can support high flows of groundwater. Water company  wellfields are sited in such formations because the they can take heavy  withdrawals without running dry. The intent of this program is to identify and  map lands around such wellfields that supply water to more than 1,000 people.  The program is still evolving, but businesses that use hazardous materials, gas  stations, dry cleaners and other facilities with the potential for contaminating  the groundwater will come under municipal regulation and possibly some zoning or  other land use restrictions.

Federal Regulations
The major legislative underpinnings for EPA water regulations are the Clean Water Act and  the Safe Drinking Water Act. The federal water regulations that implement  these acts are found at 40 CFR 100 through 149:

104 -- Public hearings on effluent standards for toxic pollutants
108 --  Employee protection hearings
109 -- Criteria for state, local and regional  oil removal contingency plans
110 -- Discharge of oil
112 -- Oil pollution  prevention
113 -- Liability limits for small onshore storage  facilities
114 -- Civil penalties for violation of oil pollution prevention  regulations
116 -- Designation of hazardous substances
117 --  Determination of reportable quantities for hazardous substances
121 -- State  certification of activities requiring a federal license or permit
122 -- EPA  administered permits: The national pollutant discharge elimination system
123  -- State program requirements
124 -- Procedures for decision making
125 --  Criteria and standards for the national pollutant discharge elimination  system
129 -- Toxic pollutant effluent standards
130 -- Water quality  planning and management
131 -- Water quality standards
133 -- Secondary  treatment regulation
135 -- Prior notice of citizen suits
136 --  Guidelines establishing test procedures for the analysis of pollutants
140 --  Marine sanitation device standard
141 -- National primary drinking water  regulations
142 -- National primary drinking water regulations  implementation
143 -- National secondary drinking water regulations
144 --  Underground injection control program
145 -- State UIC program  requirements
146 -- Underground injection control program: Criteria and  standards
147 -- State underground injection control programs
149 -- Sole  source aquifers

(Note that there are other federal water regulations at 40 CFR 403 et seq  regarding effluent guidelines and  standards that set limits for discharges into sanitary sewer systems.)

Other Useful Information
DEP has developed a number of fact sheets summarizing its water regulatory programs,  including:

• Connecticut Clean Water Act
• Water Resource Management
• Clean Water Fund
• Water Quality Standards and Classifications
• Aquifer Protection Areas
• Ambient Surface Water Monitoring
• Lake Water Quality Management
• Rivers Management
• Inland Wetlands Management
• Nonpoint Sources
• Water Quality of Long Island Sound
• Coastal Management
• Property Transfer
• Wastewater Discharge Permits
• Urban Sites Remedial Action

Hot Topic Archive

2. Regulated Water Discharge Sources

Industrial wastewater discharges in Connecticut mainly end up in surface waters,  either via a direct discharge (a pipe or outfall or storm drain connection), or  via an indirect discharge (a sewage treatment plant, also known as a  publically-owned treatment works or POTW).

Direct discharges are those which empty from a facility  wastewater discharge pipe into a surface water body. They may discharge either  from an outfall on the facility property right into the waterbody, or they may  enter a storm drain system and be discharged into the water body at some  distance from the facility. In either case, these are called direct discharges.  They require an NPDES permit.

Indirect discharges are those which are directed to a sanitary line, and  flow to the local sewage treatment plant. The wastewater gets processed through  the sewage treatment plant before being released to a surface water body. These  discharges require a state permit (also sometimes called a pretreatment permit,  a SPDES permit, or a POTW permit).

In addition to direct and indirect discharges, there are area discharges (also called nonpoint source discharges). These result from runoff of  precipitation from ground surfaces (farms, golf courses, construction sites,  roads and highways, urbanized or industrialized areas). Some air emission  sources can result in contributions to surface water discharges. This  particularly applies in situations where vented material condenses or deposits  onto roofs or the ground nearby and is subsequently rinsed off by rainfall into  storm drains, and makes its way to a stream or river.

In general, very few industrial plant wastewater discharge sources are not covered by Connecticut water regulations. Unlike the air regulations  (where there is a 5 tons/yr potential to emit threshold for permitting), there  is no universal exclusion that lets water discharges off the hook if  they're small. This makes sense, because while the atmosphere has reasonably  consistent dispersive capacities, dispersive capacity in water bodies depends on  the flow (i.e., size of the stream). Even a small discharge could cause a water  quality problem if discharged into a small stream where it didn't get diluted  very much, whereas it would have no effect on a big flow like the Connecticut  River.

However, there are several specific exemptions from regulation for industrial  or commercial facility water discharges that are not considered wastewater  (e.g., drips of condensed atmospheric moisture from the cool side of chiller  systems). Also, some of the general permits have discharge rate thresholds  (e.g., 500 to 5,000 gal/day) below which no registration for a permit is needed.  See the list in the general  permits section.

If there's any uncertainty, the prudent course for a plant manager is to  presume any manufacturing process with a wastewater discharge, as well as any process wastewater treatment system discharge, is covered by  Connecticut water regulations regardless of the discharge rate. Also, a plant  manager should presume discharges from the facilities infrastructure (blowdown  from heating boilers, bleeds from chiller systems, condensate from air  compressors) are covered by regulation, and then check to see if they're below a  size threshold requiring permitting.

3. Discharge Permit Limits and Other Standards

The underlying standard for discharges to surface waters is:

• no impairment to stream quality (outside a localized mixing zone);
• no backsliding from the fishable/swimmable goals of the Clean Water Act.

The underlying standard for discharges to sanitary sewer systems (called  publicly-owned treatment works, or POTWs) is:

• no adverse effect on treatment plant operations;
• no pass-through of wastes (at concentrations that would cause the treatment  plant to violate its own permit limits);
• pretreatment standards met (these are numerical concentrations of  contaminants specified in EPA regulations for specific  industrial categories, or in some cases set by the local  sewage treatment plant).

The underlying standard for discharges to groundwater (septic systems, dry  wells, leaching galleys, unlined lagoons or settling basins) is:

• no adverse impact on any water supply;
• no exceedance of groundwater protection criteria (even if no wells are in the area).

Except for sanitary wastes and a few special exceptions in general permits,  DEP discourages discharges to ground, and in most cases an individual permit  application is typically required. Also, other regulatory controls may exist in aquifer protection areas.

The standards are achieved by applying specific limits to effluent  concentrations in a facility wastewater, either in a discharge permit for a  surface water (NPDES) or a discharge permit for a sanitary sewer system (SPDES).  Since industrial processes are numerous and varied, and the flow and quality of  the receiving waters likewise, individual permits are written specific to each  facility. The discharge limits in those permits also are specific to each  facility and to the pollutant(s) discharged.

Over the past decade or so, there has been an evolution in the concept of  standards for discharges into surface waters.

• Originally, discharge limits were set for end-of-pipe contaminant  concentrations that would (outside of a localized mixing zone) not be  harmful to the water body, nor interfere with other uses of the water  downstream.
• Next came water-quality-based standards, in which judgments were made  about what levels of contaminants could be allowed in a particular stretch of  river or stream without adverse effects on aquatic life or human health.
• At present, there is a lot of consideration being given to aquatic  toxicity testing of the effluent, under the presumption that if the test  organisms can survive at certain levels in the discharge, the discharge will be  okay in a surface water body.

As a practical matter, future standards will probably embrace parts of all  three concepts.

Categorical Pretreatment  Standards
EPA has set specific standards for a number of industrial processes for  requirements to pre-treat their discharges before putting them into a sanitary  sewer line. The purpose is to put the burden of treatment on the facility  producing the wastewater, rather than on the local sewage treatment plant. The  facility is better equipped to know how to treat it, and in any case it's more  treatable before being mixed with other inputs to a sewage treatment plant.  These standards begin at 40 CFR 403. To see which one may apply to your  facility, go to the EPA website  regulations page, navigate to the appropriate CFR section, and read the  applicability paragraph. The parts of 40 CFR covering effluent guidelines and  standards are:

403 General pretreatment regulations (applies to all industries hooked to a  POTW)
405 Dairy products processing
406 Grain mills
407 Canned and  preserved fruits and vegetables processing
408 Canned and preserved seafood  processing
409 Sugar processing
410 Textile mills
411 Cement  manufacturing
412 Feedlots
413 Electroplating
414 Organic chemicals,  plastics, and synthetic fibers
415 Inorganic chemicals manufacturing
417  Soap and detergent manufacturing
418 Fertilizer manufacturing
419  Petroleum refining
420 Iron and steel manufacturing
421 Nonferrous metals  manufacturing
422 Phosphate manufacturing
423 Steam electric power  generating
424 Ferroalloy manufacturing
425 Leather tanning and finishing
426 Glass manufacturing
427 Asbestos manufacturing
428 Rubber  manufacturing
429 Timber products processing
430 Pulp, paper, and  paperboard
431 Builders' paper and board mills
432 Meat products
433  Metal finishing
434 Coal mining
435 Oil and gas extraction
436 Mineral  mining and processing
439 Pharmaceutical manufacturing
440 Ore mining and  dressing
443 Paving and roofing materials (tars and asphalt)
446 Paint  formulating
447 Ink formulating
454 Gum and wood chemicals  manufacturing
455 Pesticide chemicals
457 Explosives manufacturing
458  Carbon black manufacturing
459 Photographic
460 Hospitals
461 Battery  manufacturing
463 Plastics molding and forming
464 Metal molding and  casting
465 Coil coating
466 Porcelain enameling
467 Aluminum  forming
468 Copper forming
469 Electrical and electronic components
471  Nonferrous metals forming and metal powders

Local POTW  Standards
Some towns in Connecticut have their own local ordinances limiting the  concentrations they will accept in effluents discharged into their sewerage  system. These limits typically apply at the point of entry (usually the  sewer connection in the street), not necessarily at the process or treatment  system discharge inside the plant. For a facility with many waste streams  (including sanitary), meeting the state discharge permit limits for each process  inside the plant usually assures that the local ordinances are met at the sewer  connection in the street, but there are enough possible exceptions to make this  worth checking. For example, for an industrial metal parts tumbling and cleaning  operation, the discharge limits in the town of Wallingford water and sewer  regulations differ from those in the DEP's general permit:

Contaminant CT Minor Tumbling and Cleaning General Permit Limit  (mg/L) Town of Wallingford Water and Sewer Regulations Limit  (mg/L) cadmium 0.5 0.05 chromium 2.0 1.0 copper 2.0 0.5 lead 0.5 0.1 nickel 2.0 0.28 tin 4.0 none specified titanium 4.0 none specified  zinc 2.0 1.40

The requirements apply at different points in the facility's sanitary sewer  piping, so Wallingford's discharge limits are not necessarily more stringent,  but such situations require evaluation.

Aquifer Protection  Areas
The Connecticut Aquifer Protection Area Program may impose operating criteria  or best management practices (which are not numerical standards) on facilities  located within an aquifer protection area. An aquifer (from the Latin aqua  (water) plus ferre (to carry)) is a geologic formation consisting of well-sorted  sands and gravels that can support high flows of groundwater. Water company  wellfields are sited in such formations because the they can take heavy  withdrawals without running dry. The intent of this DEP program is to identify  and map lands around each such wellfield that supplies water to more than 1,000  people. The program is still evolving. There are no numerical standards or  criteria for discharges to ground in such areas; the basic idea is that there  should be no discharges at all. Businesses that use hazardous materials, gas  stations, dry cleaners and other facilities with the potential for contaminating  the groundwater will come under municipal regulation and possibly some zoning or  other land use restrictions.

4. Types of Water Permits

Individual NPDES Permits are written for  facility discharges of treated industrial wastewaters to a surface water body.  Such permits typically include requirements for operating the facility  wastewater treatment system, periodic monitoring of the discharges, and monthly  reporting to DEP. Any type of industrial wastewater discharge to a surface water  body is required to apply for an individual permit, unless covered by a general  permit, or specifically exempted by DEP.

Individual State Permits are written for  discharges of treated industrial wastewaters to a publically-owned treatment  works (POTW, a municipal sanitary sewer system). These are also known as SPDES  permits or POTW permits. Since the discharges usually require pretreatment at  the facility before entry into the local sewer connection, such permits  typically include requirements for operating the facility wastewater treatment  system, periodic monitoring of the discharges, and monthly reporting to DEP.

General Permits are written for discharge  categories, not individual facilities. They require registration with DEP, and  typically a registration number is assigned to the facility. Such permits are  quick, inexpensive, and appropriate for many kinds of small discharges typical  of commercial and industrial activities. Some of these permits allow discharges  to the ground or to a surface water, but most are for discharges to a sanitary  sewer line.

Individual Permits
Manufacturing processes in Connecticut are many and varied. Some date back  almost to the industrial development period around the Civil War; some are in  cutting-edge aerospace, electronic or medical areas that weren't even envisioned  a decade ago. Some of the water-borne waste streams from these processes are  innocuous; some are highly toxic. Some wastewaters need no treatment, or very  simple treatment like pH adjustment; some need extensive wastewater treatment  systems to remove contaminants to very low levels. The thing to remember is that  any process wastewater discharge from any manufacturing facility in Connecticut  is subject to the basic requirement to apply for a permit. If a general permit  can't be used, an individual permit must be applied for.

Adherence to the permit limits is verified by periodic monitoring, which  involves sampling and analysis of the discharge(s) and reporting of the results  on a monthly Discharge Monitoring Report (DMR) form. The DMRs are periodically  screened for violations by DEP staff, so it's important to resolve wastewater  treatment system problems as soon as they develop (e.g., replace bad sensors,  clean out plugged connections, rewrite procedures to prevent human error). DMRs  are public information and may also be reviewed by environmental activist groups  looking for sloppy operations and a target for a citizen's action suit.

General Permits
General permits have been a very useful regulatory development for many small  industrial and commercial dischargers. They allow streamlined registration,  reduced monitoring and lower operating costs. They apply to discharges  which:

• are common to many commercial or industrial facilities;
• typically have low discharge flows; and
• carry relatively low environmental risk.

No registration or application is required if the discharges are below  general permit registration thresholds. On the other hand, large dischargers may  not qualify for a general permit, and would need to apply for an individual  permit. To determine where your discharge falls, consult the table below:

Wastewater Discharge Receiving Water Register for general permit if above (gal/day) Get individual permit (or meet some other requirement*) if above  (gal/day) Minor Non-Contact and Heat Pump Cooling  Waters (such as chillers for building central cooling systems, heat  exchange loops in process cooling systems) Surface water Groundwater Sanitary sewer 0 5,000 5,000 500,000 500,000 50,000 Minor Tumbling and Cleaning  Wastewaters (such as scrubbing, descaling, grit blasting, rinsing or  barrel tumbling for deburring in a water solution of some type) Surface water Groundwater Sanitary sewer Not avbl ** Not avbl ** 0 0 0 50,000 Minor Boiler Blowdown (the periodic  or episodic release of a fraction of the water in steam boilers or steam  generators for control of scale and corrosion) Surface water Groundwater Sanitary sewer Not avbl ** No regis*** No regis*** 0 5,000 5,000 Vehicle Service Floor Drain  Wastewaters (such as commercial auto or fleet repair facilities where  water drains from the floor into an oil/water separator tank) Surface water Groundwater Sanitary sewer Not avbl ** Not avbl ** 0 0 0 1,000 Car Wash Wastewaters (such as  commercial auto wash facilities where no repair work is done and wash water  drains from the floor into a grit settling tank) Surface water Groundwater Sanitary sewer Not avbl ** Not avbl ** 0 0 0 10,000 Minor Photographic Processing  Wastewaters (such as film developing for photos, x-rays or other  silver-based processes, where a silver recovery unit is used) Surface water Groundwater Sanitary sewer Not avbl ** Not avbl ** 0 0 0 5,000 Minor Printing and Publishing  Wastewaters (washwater and cleanup rinses from letterpress, flexography,  lithography and other printing processes) Surface water Groundwater Sanitary sewer Not avbl ** Not avbl ** 0 0 0 1,000 Food ProcessingWastewaters (washing,  rinsing, or cleaning of equipment and process areas used to prepare food for  human or animal consumption) Surface water Groundwater Sanitary sewer Not avbl ** Not avbl ** 0 0 0 50,000 Groundwater Remediation Wastewaters (groundwater treatment systems discharges in which contaminants have been  reduced to acceptable levels) Surface water Groundwater Sanitary sewer Not avbl ** Not avbl ** 0 0 0 50,000 Water Treatment Wastewaters (various  process discharges from water company facilities; doesn't apply to most  industrial situations unless they condition raw water) Surface water Groundwater Sanitary sewer 0 0 0 1,000,000 50,000 Not specified Miscellaneous Wastewaters(in draft) (such as various building infrastructure devices  with periodic flushes, like water softeners or air compressor system  condensate) Surface water Groundwater Sanitary sewer Not avbl ** Not avbl ** 500 0 0 5,000

*If above the thresholds listed, either an individual permit is  required (so DEP can examine the situation by means of a permit application and  usually a site inspection) or some other action under the general permit (such  as getting an engineering certification that the discharge meets the permit  requirements).

**The general permit is not available for discharges to these  receiving waters. DEP wants to see an individual permit application for these,  and will write a permit to assure that appropriate treatment systems are  installed, discharge limits are set, and other site-specific permit conditions  are developed.

Note that there are other conditions besides flow affecting whether or not  you can use a general permit. Such things as the presence or use of treatment  chemicals, or specific exclusions (usually written into the permit applicability  or definitions sections) may keep you from using it. There are several other  general permits, including three for stormwater runoff. There is also a  temporary discharge authorization, which may be filed for dewatering of  excavations or trenches, or other activities of a short-term nature. There are a  number of other DEP water permits typically not related to industrial wastewater  discharges, and usually not of much interest to the commercial/industrial  sector. These include such things as docks extending into waterways, withdrawal  of more than 50,000 gal/day of water from the ground or a surface water for  consumptive use, and construction work in waterways or wetlands. For a brief  description of all water permits currently on the books, go to theConnecticut Licensing Info  Center, and search the Environmental category for the keyword Water. To get more detailed information, fact sheets and downloadable  permit application forms, go to the DEPUser's Guide to Environmental Permits.

5. Treatment Systems for Water Discharges

In general, the unit processes available to treat wastewater streams are:

An example of several of these technologies for an electronics manufacturer  is shown below.

Example Manufacturing Process (Production of  Electronic Printed Circuit Boards)

Water Balance through Manufacturing Process

Wastewater Treatment System

Wastewater Technology Information  Sources

The web has a lot of marketing information on equipment for wastewater  treatment systems, and even entire package treatment systems. Several of the  more useful listing services to start with are:

• AWMA's  product guide (Air & Waste Management Association).
• Pollution Engineering's  guide to equipment vendors.
• Environet's referral guide  to equipment vendors.

Use the search function on these websites to find the equipment you're  interested in.

6. Key Questions for Water Discharges

This link will open an Adobe pdf file to display a list of key questions to ask yourself on water  discharges. (You need Adobe Acrobat Reader v3.0 or later  enabled on your browser as a helper to view this list. To return to this page  after viewing the list, just click the browser back button. If you don't  have this free software, we suggest you download Acrobat Reader).

These questions are the most common starting questions for environmental  auditing of small and mid-sized manufacturing facilities in Connecticut. Depending on your browser and platform, to print a paper copy of  the questions you may need to first Save As a .pdf file on your hard drive.

Home | About This Site | Topics | Features | About AEI | Take a Break | Feedback
Site Map | Pick of the Month | Ask Our Experts | Ecological Assessment