Course: BFM 203 Water Treatment and Control

Lecture

(5/5)

Articles

The following information highlights some of the articles in Colorado drinking water regulations.

Article 2

Article 2 addresses MCLs of certain contaminants. Note that MCLs here are measured in mg/L unless otherwise noted. Following is a list of the more commonly known and regarded MCL's.

Contaminant | MCL
Asbestos | 7 million fibers/L (n longer than 10 μgm)
Fluoride | 4.0
Nitrate | 10
Nitrite | 1
Combined Nitrite and Nitrate | 10
TTHMs | 0.08
HAA_5 | 0.06

Article 3

Article 3 addresses SMCLs. Note that MCLs here are measured in mg/L unless otherwise noted. These secondary MCL's are not enforceable, but instead are guidelines. Some of the secondary MCL's represent lower concentrations of the primary MCL's. but only affect aesthetics of the water, not necessarily the safety.

Contaminant | MCL or Other Measure
Color | 15 color units
Fluoride | 2.0
Iron | 0.3
Manganese | 0.05
Odor | 3 threshold
pH | 6.5 - 8.5

Article 4

Article 4 addresses variances and exceptions that MAY be given to utilities based on certain factors. An exception is temporary relief from an MCL, pending installation of a treatment technique (TT). A variance is relief from an MCL due to source water when using BAT. The granting of an exception will not result in unreasonable risk to health. A variance is not indefinite; a schedule for compliance is part of the written document. NO variances or exceptions are allowed for the following contaminants:

- MCL for coliforms
- TT for surface water filtration
- Disinfectant residual at POE for surface water

Article 5

Article 5 addresses microbiological contaminants such as coliform. Coliform sampling is population based. If five samples or fewer are required, they may be taken in one day (groundwater only). If one or more samples is positive, a minimum of three samples must be taken; one at the original sample site, one within five service connections upstream, and one within five service connections downstream, and one at each source entry point. If the system is groundwater based, each well counts as one source entry point. All repeat samples must be taken within 24 hours of receiving the positive result. All samples taken must be at least 100 mL in volume and contain a dechlorination agent, such as sodium thiosulfate. Communication with the CDPH&amp;E, Water Quality Control Division about any positive samples and corrective actions in progress is crucial to avoiding missed steps or misunderstanding the regulations.

Article 6

Article 6 addresses chemical contaminants and radionuclides. Nitrates are a concern specifically because of the effects of methmoglobanimia, commonly known as blue baby syndrome, on infants. Nitrates in a non community system may exceed 10, but no more than 20 if the following requirements are met:

- Water is not available to children under 6 months of age
- Notification is provided to the public
- Notification is provided to state and local officials
- No adverse health effects are reported

When MCL is exceeded, a second sample will be taken within 24 hours; the average of the two will determine compliance.

Article 7

Article 7 addresses filtration, disinfection, and disinfection byproducts. Turbidity sampling requirements also apply to the effluent of each filter. Testing must confirm 99 percent (2 log) removal of Cryptosporidium, 99.9 percent (3 log) removal of Giardia,and 99.99 percent (4 log) removal of viruses.

Turbidity requirements with use of direct, conventional, or membrane filtration should be 0.3 NTU, no greater than 1 NTU. When using bag, cartridge, slow sand, or diatomaceous Earth processes, turbidity should be 1 NTU, no greater than 5 NTU. If the population served is fewer than 3,300, utilities may take grab samples for measurement every four hours of operation. If the population served is greater than 3,300, utilities must have continuous monitoring systems in place (on-line meters). If that fails, grab tests must be taken every 4 hours and the system must be restored within five days if the population served is more than 10,000; within fourteen days if the population served is between 3,300 and 10,000. All violations must be reported within 24 hours.

Disinfection is required to follow the same rules as turbidity except that the minimum is 0.2 and service must be restored within 4 hours.

Disinfection byproducts include TTHM and HAA5, both of which may have adverse health effects on the public. Testing for surface water may be performed annually if the population served is fewer than 500. Testing must be performed quarterly if the population served is greater than 500. Testing for groundwater can be performed annually in each treatment plant if the population served is less than 10,000. Treatment must be performed quarterly if the population served is greater than 10,000. Note that each aquifer is considered a treatment plant.

A system must develop and implement a monitoring plan to be kept on file for Department and public review. The monitoring plan must contain (1) monitoring locations, (2) monitoring dates, (3) compliance calculation procedures, and (4) monitoring plans for any other systems in the combined distribution system if the Department has reduced monitoring requirements, and be complete no later than the date on which you conduct your initial monitoring under the directions of Article 7.

Article 8

Article 8 addresses lead and copper. The lead MCL is 0.015; copper, 1.3. If MCLs have been met for two consecutive six-month sampling periods, no corrosion control is required. Types of corrosion control include alkalinity control, pH control, Ca and hardness adjustment, and the addition of phosphate and silica. Note that lead and copper have "action levels" instead of MCLs. Action levels are calculated at the 90th percentile of the samples taken.

A number of monitoring levels exist as outlined here. This tier system is designed to identify service lines that are most likely to leach lead and/or copper into the water sitting in the pipe. In fact, the monitoring requirements and sampling protocol are designed to identify the worst-case scenario and then to take corrective actions if necessary.

Tier 1 - Single-family homes containing copper pipes with lead solder installed after 1982 or serviced by a lead line.

Tier 2 - Multiple family residences built after 1982.

Tier 3 - Single-family homes containing copper pipes with lead solder installed before 1983 or serviced by a lead line.

If system contains lead service lines, at least 50 percent of the samples must be taken from those areas. First draw samples consist of 1L of water taken at a point of consumption with water standing in pipe for at least six hours. DO NOT FLUSH THE TAP BEFORE SAMPLING!

Article 9

Article 9 addresses consumer notification. Each utility must prepare and make available a consumer confidence report that is to be available by July 1 of each year. This report must contain information on source water, MCL, MCLG, TT, AL, turbidity, and data on the highest levels and range of contaminants in whole numbers (i.e., 0.2 mg/L = 200 ppb. In addition, the report must contain the following data sets: turbidity, lead and copper, coliforms, residuals, variances, and violations. All reports must be written in a way that is understandable to the average customer and made available translated into other languages as needed. All reports must prominently display the following language:

"Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons, such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. EPA/CDC guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline (800-426-4791)."

This article also mandates that the public must be notified within 24 hours of any Tier 1 threat to public health. This includes coliform, nitrates, and TT violations. The public must be notified within 30 days of any Tier 2 threat (threats that may pose a long-term risk). This includes lead, copper, monitoring violations, and variances granted. Tier 3 notifications must occur with 1 year. All notices must remain in place for a minimum of 7 days and be posted in such a way to reach all persons in a district. The district must make a good faith effort to provide reports to all customers, even if they are not the billed customer. For example, apartment tenants should be notified.

Article 10

Article 10 addresses analytical requirements and lab certification. It covers specific methods of analysis for contaminants by state certified labs, so it is not information that is critical to you at this time. State certification for labs is based on the equipment, method, records, and analyst.

Article 11

Article 11 addresses the sanitary survey requirement. Utilities must perform a groundwater sanitary survey every 5 years for community and non-community and every 10 years for non-community if disinfected and protected. A surface water sanitary survey should be performed every 3 years for community, and may be extended to every 5 years if the system has an outstanding performance record. The survey should be performed every 5 years for non-community. The sanitary survey must be performed by CDPHE or an approved third party. The Survey consists of source, treatment, distribution systems, finished water storage, pumping facilities and controls, monitoring, operator compliance and certification. Collection of data for the sanitary survey may be done by CDPHE, approved third party, and/or district personnel.

Article 12

Article 12 addresses hazardous cross connections. All potential sources of cross connections must be identified. Records must be kept on all potential sources and devices in place to prevent cross connection. Inspection of and maintenance on those devices (backflow prevention) are to be performed by a certified technician. Each point in the system should be re-evaluated every two years. Illegal cross-connections are one of the greatest concerns for operators of distribution systems. They are a likely source of contamination and are not easily identifiable.

Article 13

Article 13 is a groundwater rule. This applies only to systems that use groundwater as their only source, not in combination with surface water or ground water under direct influence of surface water. CDPHE may grant waivers for disinfection with many strings attached. A positive test for coliform will trigger sampling of not only the three previously mentioned, but also one from each and every well that was running at a point in time to influence the sample taken. Alternatively, the utility may provide proof to CDPHE that there is 4-log removal before water reaches the first customer OR provide continuous monitoring of disinfectant level. Disinfectant waivers may be granted for groundwater systems, but a disinfectant residual in the distribution system is still the most reliable way to ensure delivery of safe drinking water to each customer.