Waikoloa District 2019 Water Quality Report

Welcome

Washing handsAt Hawaii Water Service (Hawaii Water), our goal is to deliver safe, high-quality drinking water, 24 hours per day, seven days per week, 365 days per year. As part of that effort, we produce this annual water quality report, which includes information about where your water comes from, what it contains, and how it compares to state and federal standards. Most importantly, it confirms that in 2019, our water met or surpassed all standards set by the Hawaii Department of Health and U.S. Environmental Protection Agency (EPA) to protect public health.

Your Water System

Water pipesrWaikoloa's drinking water is monitored and tested by our laboratory as well as an independent, certified laboratory and the Hawaii Department of Health for all contaminants established by the Safe Drinking Water Act.

Waikoloa's water comes from 1,200-feet-deep wells that draw from an underground aquifer that is continuously flushed and replenished. Waikoloa's drinking water wells are located at an elevation above Waikoloa Village. There are no development, industry, or injection pits located above Waikoloa's drinking water wells that could be a possible source of contamination. Waikoloa's water is continuously disinfected and delivered to our customers through reservoirs and distribution mains that are lead-free, and our water is non-corrosive due to a balanced pH between 7.9 and 8.3, and an alkalinity between 82 and 100.

The Hawaii Department of Health's Safe Drinking Water Branch completed the preliminary draft of Waikoloa's source water assessment and protection program in March 2004. For more information, please contact our Customer Center at (808) 883-2046.

For additional drinking water quality information, contact:

Possible Contaminants

Eyedroper and microscope slideDrinking water, including bottled water, may be reasonably expected to contain at least small amounts of some substances. The presence of substances does not necessarily indicate that the water poses a health risk.

More information about substances and potential health effects can be obtained by calling the EPA's Safe Drinking Water Hotline at (800) 426-4791.

Protecting Your Water

In general, the sources of drinking water (both tap and bottled water) include rivers, lakes, streams, ponds, reservoirs, and wells. As water travels over land's surface or through the earth, it dissolves naturally occurring minerals and can pick up substances resulting from the presence of animals or human activity. Contaminants that may be in untreated water include:

  • Microbial contaminants, such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
  • Inorganic contaminants, such as salts and metals, which can be naturally occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming. Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses.
  • Organic chemical contaminants, including synthetic and volatile organic chemicals, which are byproducts of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, and septic systems.
  • Radioactive contaminants, which can be naturally occurring or be the result of oil and gas production and mining activities.

To ensure that tap water is safe to drink, the EPA prescribes regulations that limit the amount of certain contaminants in water provided by public water systems. The Food and Drug Administration regulates contaminants in bottled water to protect public health.

Individuals with Special Health Concerns

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

Cross-Connection Control

To ensure that the high-quality water we deliver is not compromised in the distribution system, Hawaii Water has a robust cross-connection control program in place. Cross-connection control is critical to ensuring that activities on customers' properties do not affect the public water supply. Our cross-connection control specialists ensure that all of the existing backflow prevention assemblies are tested annually, assess all connections, and enforce and manage the installation of new commercial and residential assemblies.

Backflow can occur when certain pressure conditions exist either in our distribution system or within the customer's plumbing, so our customers are our first line of defense. A minor home improvement project — without the proper protections — can create a potentially hazardous situation, so careful adherence to plumbing codes and standards will ensure the community's water supply remains safe. Please be sure to utilize the advice or services of a qualified plumbing professional.

Many water use activities involve substances that, if allowed to enter the distribution system, would be aesthetically displeasing or could even present health concerns. Some common cross-connections are:

  • Garden hoses connected to a hose bib without a simple hose-type vacuum breaker (available at a home improvement store)
  • Improperly installed toilet tank fill valves that do not have the required air gap between the valve or refill tube
  • Landscape irrigation systems that do not have the proper backflow prevention assembly installed on the supply line

Customers must ensure that all plumbing is in conformance with local plumbing codes. Additionally, state law requires certain types of facilities to install and maintain backflow prevention assemblies at the water meter. Hawaii Water's cross-connection control staff will determine whether you need to install a backflow prevention assembly based on water uses at your location.

About Lead

MoleculesAs the issue of lead in water continues to be top of mind for many Americans, Hawaii Water wants to assure you about the quality of your water.

None of these conditions exist at Hawaii Water. We have worked proactively to eliminate lead-bearing materials from our water systems, and we are compliant with health and safety codes mandating the installation of lead-free materials in public water systems. We test our water sources to ensure that the water we deliver to customers' meters meets water quality standards and is not corrosive toward plumbing materials.

The water we deliver may meet lead standards, but what about your home plumbing? Because lead in drinking water comes primarily from materials and components associated with service lines and home plumbing, the Lead and Copper Rule is a critical part of our water quality monitoring program.

The Lead and Copper Rule requires us to test water inside a representative number of homes that have plumbing most likely to contain lead and/or lead solder. This test, with other water quality testing, tells us if the water is corrosive enough to cause lead from home plumbing to leach into the water. If the “Action Level” for lead is exceeded, we work with our customers to investigate the issue and, if necessary, implement corrosion control before the lead levels create a health issue.

Elevated levels of lead, if present, can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. Hawaii Water is responsible for providing high-quality drinking water, but cannot control the variety of materials used in plumbing components.

When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to two minutes before using water for drinking or cooking. If you are concerned about lead in your water, you may wish to have your water tested by a certified lab. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline or at www.epa.gov/safewater/lead.

In your system, results from our lead monitoring program, conducted in accordance with the Lead and Copper Rule, were non-detectable for the presence of lead.

Table Introduction

Close up of waterThe 2019 Water Quality Table lists all of the contaminants that we detected in your drinking water in 2019 (except where noted).

Although the EPA requires water systems to test for up to 125 substances, we list only those substances detected in your water. The state allows us to monitor for some substances less than once per year because the concentrations of these substances do not change rapidly.

Key Definitions

  • Maximum Contaminant Level Goal (MCLG): Level of a contaminant in drinking water below which there is no known or expected risk to health; MCLGs allow for a margin of safety
  • Maximum Contaminant Level (MCL): Highest level of a contaminant that is allowed in drinking water; MCLs are set as close to the MCLGs as feasible using the best available treatment technology
  • Action Level (AL): Concentration of a contaminant which, if exceeded, triggers treatment or other required action by the water provider

Water Quality Table

Primary Drinking Water Standards

Inorganic Chemicals Year Tested Unit MCL (SMCL) MCLG In Compliance Range Average Source of Substance
Chromium 2017 ppb 100 100 Yes 4.0–4.6 4.27 Discharge from steel and pulp mills and chrome plating; erosion of natural deposits
Fluoride 2019 ppm 4 4 Yes 0.21–0.29 0.25 Erosion of natural deposits; water additive that promotes strong teeth; discharge from fertilizer and aluminum factories
Nitrate (as nitrogen) 2019 ppm 10 10 Yes 1.1–1.3 1.2 Runoff and leaching from fertilizer use; leaching from septic tanks and sewage; erosion of natural deposits
Disinfection Byproducts Year Tested Unit MCL (SMCL) MCLG In Compliance Range Average Source of Substance
Total trihalomethanes 2019 ppb 80 n/a Yes 5.2–7.0 6.1 Byproduct of drinking water chlorination
Total haloacetic acids 2019 ppb 60 n/a Yes ND–1.4 0.7 Byproduct of drinking water chlorination
Disinfectant Year Tested Unit MRDL MRDLG In Compliance Range Average Source of Substance
Chlorine 2019 ppm 4 4 Yes 0.23–0.62 0.4 Drinking water disinfectant added for treatment

Other Regulated Substances

Metals Year Tested Unit AL MCLG In Compliance 90th Percentile Samples > AL Source of Substance
Copper 2018 ppm 1.3 0.3 Yes No detection 0 of 30 Internal corrosion of household plumbing systems; erosion of natural deposits; leaching from wood preservatives
Lead 2018 ppb 15 2 Yes No detection 0 of 30 Internal corrosion of household plumbing systems; discharge from industrial manufacturers; erosion of natural deposits

Secondary Drinking Water Standards and Unregulated Compounds

Inorganic Chemicals Year Tested Unit SMCL (MCLG) In Compliance Result or Range Average Source of Substance
Boron 2017 ppm n/a n/a Yes ND–0.057 0.029 Erosion of natural deposits
Calcium 2017 ppm n/a n/a Yes 7.9–11 9.5 Erosion of natural deposits
Chloride 2017 ppm 250 250 Yes 27–100 64 Erosion of natural deposits; seawater influence
Magnesium 2017 ppm n/a n/a Yes 12–19 16 Erosion of natural deposits
Silica 2017 ppm n/a n/a Yes 67–69 68 Erosion of natural deposits
Sodium 2017 ppm n/a n/a Yes 33–82 58 Erosion of natural deposits; seawater influence
Sulfate 2019 ppm 500 n/a Yes 15–34 25 Runoff/leaching from natural deposits; industrial wastes
Molybdenum 2017 ppb n/a n/a Yes 4.2–8 6.1 Erosion of natural deposits
Strontium 2017 ppb n/a n/a Yes 48–87 68 Erosion of natural deposits
Vanadium 2017 ppb n/a n/a Yes 56–66 61 Erosion of natural deposits; manufacturing of alloys and steel

Table Key

n/a Not applicable ppm Parts per million, or milligrams per liter (mg/L)
MRDL Maximum residual disinfectant level ppb Parts per billion, or micrograms per liter (µg/L)
MRDLG Maximum residual disinfectant level goal pCi/L Picocuries per liter (a measure of radioactivity)
ND Not detected SMCL Secondary maximum contaminant level

Thank You

FirefightersIf you have questions, comments, or concerns regarding your drinking water, please contact Hawaii Water Service. We welcome your interest in Waikoloa's water system.

A full-color, printable version of this report in PDF format is also available.

If you have any questions about your water quality table, please Contact Us.