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Are we adding too much chlorine to the water?
No. The Environmental Protection Agency allows a minimum of 0.5 ppm and a maximum of 4.0 ppm of chlorine residual in drinking water supplies. The city maintains an average of 1.1 ppm in its drinking water.
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Are we required to add chlorine to the water?
Yes. Under the Safe Drinking Water Act, the City is required to add chlorine disinfection to its treatment process with a residual no less than 0.50 parts per million (ppm) and no higher than 4.0 ppm in the water distribution system.
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Did the City make any changes to the water pressure of the system?
The City has not made any changes to the City’s water pressure.
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Do all the leaks occur on cold water pipes?
No. A majority of the leaks occur on the cold water pipes, but some have occurred in the hot water pipes.
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Does anyone know what was specifically changed in the water supply recently? Does anyone know why our pH is at 9?
There were not changes in the water supply. The consultant team believes the more likely explanation for pH in the City’s system is that the pH reading at the entry point is too close to the lime feed point where the water is still reacting to the chemical addition due to the low buffering capacity. In some distribution system reservoirs, residual lime can settle out, which could increase the pH within the distribution system.
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Does the City add any chemicals to prevent corrosion?
Like neighboring water agencies, the City uses lime for pH adjustment and corrosion control purposes. The amount used is consistent with accepted industry-practices for treating drinking water.
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Does the City have hard water?
The City water hardness, which ranges from 17-33 within the system, is considered slightly hard based on the following range:
- 0-17.1: Soft
- 17.1-60: Slightly Hard
- 60-120: Moderately Hard
- 120-180: Hard
- Over 180: Very Hard
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Does the City have to report these pinhole leaks to the State Water Resources Control Board?
The City does not have to report these pinhole leaks to the State Water Resources Control Board (SWRCB). Although not required, the City did inform the SWRCB – Division of Drinking Water of the occurrence of pinhole leaks within the City’s water system. City staff and SWRCB staff met in September to discuss the pinhole leaks.
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Does the City perform laboratory tests for heavy metals?
Yes. On a quarterly basis, the City tests for the following metals: calcium, copper, iron, magnesium, manganese, potassium, silver, sodium, and zinc.
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Does the City use chloramines in their water system?
The City does not use chloramines in the water treatment process. The City uses sodium hypochlorite, which is an industry-accepted standard disinfectant to provide for safe and healthy drinking water.
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Does the City’s water have a low pH?
Any solution with a pH level below 7 is acidic, and the City’s water system pH being in the 7.7-8.2 range means that the City’s water is not acidic.
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Has the City made any changes to the treatment process recently, in the last 5 years?
The City has not made any changes to its treatment process or to the type of disinfectant chemicals used in the treatment process in the last 5 years.
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Has the City made any changes to the water pressure?
The City has not made any operational changes within the last 10 years to the water pressure in the system. The City is required to deliver at all times, at a minimum, 20 pounds per square inch (psi) of operating pressure to the City’s water customers. The California Plumbing Code requires a pressure regulator to be installed when static operating pressures exceed 80 psi.
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How does the City’s treatment process and use of chemicals compare to neighboring water agencies?
While not all water agencies use exactly the same treatment process, the City’s treatment process and the chemicals used for pre-treatment, disinfection, and corrosion control are similar to the City’s neighboring water agencies (City of Roseville, City of Sacramento, San Juan Water District, and El Dorado Irrigation District). In many cases, the City uses the same chemicals as the other water agencies.
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How long has the City used its current disinfectant, sodium hypochlorite?
The City follows accepted industry practices for treating water for public consumption and has used sodium hypochlorite for about 20 years.
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Is the City’s water safe to drink?
The City’s water is safe to drink and meets or exceeds all State and Federal regulations.
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Is there an optimal pH target?
The optimal pH levels vary from system to system and depends on a variety of water quality parameters in the raw water and finished water. The secondary maximum contaminant level, which is a non-regulatory guideline addressing contaminants that may cause cosmetic effects or aesthetic effects in drinking water, provided a pH range of 6.5-8.5.
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What is the City doing?
The City hired a consultant with expertise in water quality and corrosion to work with specialists at Virginia Tech University to conduct detailed forensic analysis on sample copper pipes with pinhole leaks. In addition, to the forensics analysis, Black and Veatch will conduct a detailed water quality evaluation to determine if there are any trends in parameters related to corrosion
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What is the source of the City’s drinking water?
The source of the City’s drinking water supply is Folsom Reservoir.
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Where do residents in American River Canyon get their water supply?
San Juan Water District is the water provider for residents and businesses in the American River Canyon neighborhoods.
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Who can we contact about a pinhole leak?
Customers with questions or pinholes leaks can call the City’s Water Quality Division at 916-461-6177 or email pinholeleaks@folsom.ca.us.
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Who determines what the pH should be?
The process in determining the pH is described in the City’s water treatment plant operating permit, which is approved by the Division of Drinking Water. See number 1 above for the pH indicator.
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Why is the pH so high in Folsom? Is it the same as other water districts that source their water from Folsom Lake, like San Juan Water District (SJWD) and Roseville?
The average pH level in the City’s treated water is not unusually high and is similar with other water agencies, including SJWD and Roseville.
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Why the apparent increase in pH after about 2016-2017?
The variability in finished water pH is partially due to the low alkalinity and limited buffering capacity in the City’s natural water supply, combined with the approved water treatment process that meets drinking water standards. In the City’s 2016 water treatment plant permit amendment approved by the Division of Drinking Water, the City calculates pH based on the Langelier Saturation Index (LSI), which is a corrosion indicator used to adjust finished water quality parameters. Due to the purity of the raw water, the City typically operates with a negative LSI in the range of -1.4 to -1.7 after adding lime to adjust the pH, alkalinity, and calcium levels. The careful monitoring and adjustment of the lime dose, and thus the pH, help keep the LSI from decreasing further. By trying to maintain a less negative LSI to improve finished water quality, pH values increase.
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Will a whole house filtration system filter out orthophosphate the City is adding to coat the interior of the copper pipes?
According to the consultant team, certain whole house filtration systems using activated carbon as a filtering material can reduce phosphate in the water by 70-90 percent. The City recommends that if homeowners are planning to install a whole house filtration system, the homeowner should consult with the filtration system manufacturer to verify that the system does not filter out phosphates. If the filtration system filters out phosphates, this could hinder the ability of orthophosphate to limit pitting corrosion.
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Will the City make the findings of the analysis available to the public?
Yes. The City will make the findings available to the public. For a copy of the lab results provided to Black & Veatch, please email pinholeleaks@folsom.ca.us.
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Will the study provide any recommendations?
The two studies will include recommendations and/or corrective measures the City should consider implementing.
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Would a lower pH have prevented pinhole leaks?
According to the consultant team, if pH had consistently been controlled around 8.5, in all likelihood pitting would still have occurred eventually (especially with impurities and particulates in the pipes), but possibly at a later date and a lower frequency of leaks.
