Standards That Purified Water Users May Need To Think About
There are no agreed definitions of the purity levels of “Purified Water” or “Ultrapure Water” but standards or guidelines which directly specify limits on impurity levels in purified water for specified types of application have been produced for many years. Some are general in nature but others relate to the concerns of particular industries, notably pharmaceutical and electronics. After some general comments, current standards are outlined.
I have been a member of committees that developed two such guidelines and users of these documents should not underestimate the lengthy discussions and debates that are involved. The issues that need to be considered include the implications of any changes to current standards, as these are often specified in analytical or other methodologies, practical application, unambiguity and robustness to remain relevant as laboratory practises evolve, as well as accuracy and acceptability. The result of such constraints and the time and effort involved is that standards evolve carefully and cautiously! No-one wants to rewrite them more often than needed.
For these reasons, most of the standards have not been revised for a number of years. This does not mean, necessarily, that they are, in any way, out of date. The standards are revisited periodically and, if there are sufficient reasons, they will be updated. However, sometimes inertia sets in and a standard that is clearly behind the times cannot generate enough support to be changed. A clear example is the ISO standard “Water for Laboratory Use” which was last updated in 1995 and uses analytical parameters from that era.
In addition to specifying purity limits for standards, all these documents contain extensive advice on how to produce, store and use purified water successfully. They also define starting water purity and the combination of treatment processes needed to achieve the required purity. Many indicate the purity of water needed for various types of application. They, therefore, are worth reading. They contain a lot of expertise!
Purified Water Standards For The Pharmaceutical Industry
The pharmacopoeia specify a number of different grades of water for bulk use in various pharmaceutical applications. The same grades are often specified for laboratory testing. The most commonly used are Purified Water (PW) and Water for Injection (WFI). Neither is as pure in terms of resistivity or TOC as CLRW or ASTM type I. WFI includes tighter bacterial and endotoxin specifications.
Healthy Beaches Program
follow the CDC guidance by limiting their gathering to no more than 10 persons and distancing themselves from other parties by 6 feet. Local authorities have been given discretion by the Governor to make decisions about whether public beaches should be closed.
This decision is made in an attempt to reduce the spread of the virus into new communities and to slow the spread of infection in communities already affected by the virus. Before you drive there, we suggest you visit the city or county webpage to see if they have closed their marine beach(es) for the next several weeks.
In addition, sampling under the new program include fecal coliform as well as enterococci bacteria. The rationale for selecting these two bacteria for analysis and implications of the sampling results are described below.
Changes to funding levels in 2011 resulted in a return to bi-weekly sampling, the elimination of all fecal coliform sampling, and a reduction of the number of sample locations. Since enterococcus bacteria are indicators of the same types of pollution as fecal coliform bacteria
Health Implications
Enterococci are enteric bacteria that normally inhabit the intestinal tract of humans and animals. The presence of enteric bacteria can be an indication of fecal pollution, which may come from stormwater runoff, pets and wildlife, and human sewage. If they are present in high concentrations in recreational waters and are ingested while swimming or enter the skin through a cut or sore, they may cause human disease, infections or rashes.
Three ways to test pH levels in water
Water, being a liquid and a solution (i.e., when it’s not 100% pure H20) has certain chemical properties because of its makeup. All solutions are acidic, basic, or neutral, and this is determined by the pH (power of Hydrogen) scale, with values ranging from 0 to 14. Essentially, this is a measure of how many hydrogen ions are present or hydroxide ions are present.
Acidic solutions are found on the lower end of the spectrum (such as citric acid, at 2.2 pH) and can have millions of times more hydrogen ions than basic solutions. Basic solutions are found on the higher end of the spectrum (such as bleaches and oven cleaners, at 13.5 pH) and can have millions of times more hydrogen ions than acidic solutions.
A pH measurement of 7 is considered neutral. Water, in its purest form, has a PH level of exactly 7, and this provides the foundation for measuring pH levels. It is relatively easy to test the pH level of water and here are three ways to do that.
USING A PH METER
According to thehomedweller, firstly, consult with the manufacturer’s instructions and specifications to calibrate the probe and meter. One way to do this would be to test the probe by dipping it in a substance with a pH level that you are already aware of. It may be an idea to carry out the calibration exercise several hours prior to using it, if you are using the probe in the field rather than a lab. Clean the probe before using it by rinsing it with clean water and wiping the water off with a clean tissue.
USING PH PAPERS
Firstly, fill up a clean container with test water. You will need to make sure that the water level is deep enough to cover the pH testing strip. Secondly, dip one of the test strips into the container of water for a few seconds. The testing strip will change color momentarily. Once the strip has changed color, you will then be able to find out the pH level.
Lead & Drinking Water
Water produced at the City’s drinking water treatment plants does not contain lead. Lead can be found in:
water service pipes in homes built before the mid-1950s
solder used to join pipes together before 1990
leaded-brass fixtures, such as faucets and valves
As these items corrode and breakdown, lead can enter drinking water. Apartment and other buildings with more than six units do not have lead pipes, regardless of age. Lead is too soft to handle the pressure needed for these types of buildings. Lead can affect how the brain and nervous system grows
those most at risk include:
pregnant women
infants (in particular those who are fed formula made from tap water)
children under the age of six
Public Health strongly recommends replacing your side of the lead service pipe at the same time that the City is replacing its side. Cutting the pipe to replace just one portion can cause particles of lead to enter drinking water, which can lead to a temporary spike in lead levels.
The water service pipe delivers water into a building. This pipe is divided into two parts.
- The part that the City owns runs from the watermain on the street up to the property line.
- The part from the property line into the home is private property and the responsibility of the homeowner.
Lead pipes affect residential homes
Accredited Standards of Minimum Requirements
The American Water Works Association first published consensus documents in 1908. Today there are more than 180 AWWA Standards. From source to storage, from treatment to distribution, AWWA standards cover all areas of water treatment and supply.
These documents reflect the state of the industry. As new technologies emerge, new Standards develop. These AWWA standards address all facets of water treatment and delivery.
From the initial standards covering pipes, water meters and steel water storage tanks, AWWA volunteers have guided the expansion of the standards program. The Council has grown from five to 24 members, with nearly 1,600 volunteer subject matter experts serving on 72 Committees. There are 189 current AWWA Standards, and Standards Committees have produced 16 of AWWA’s Manuals of Practice.