Your Cart (0)
← Back to Regulatory and Compliance
Clean Water Starts with Effective Filtration
Access to clean, safe drinking water is one of the most fundamental public health requirements. Water treatment systems — from large municipal facilities serving millions to smaller industrial and point-of-use systems — all rely on multi-stage filtration to remove contaminants, pathogens, and particulates that would otherwise pose serious health risks.
The EPA and the Safe Drinking Water Act (SDWA) establish maximum contaminant levels (MCLs) for hundreds of substances in public drinking water. Municipal water treatment facilities are required to monitor and report their water quality against these standards continuously. Industrial facilities that discharge wastewater must comply with the Clean Water Act (CWA), which limits the concentrations of pollutants in their effluent.
Reverse osmosis (RO) is one of the most effective water purification technologies, using semi-permeable membranes to remove dissolved salts, heavy metals, bacteria, and organic compounds from water. Pre-filtration is essential before RO systems — particulates and sediment must be removed upstream to protect the expensive RO membranes from fouling and premature failure. Capsule and cartridge filters are used as pre-filters in both municipal and industrial RO installations.
Microfiltration and ultrafiltration membranes remove suspended solids, bacteria, and protozoa from source water. These processes are used in both drinking water treatment and wastewater reclamation, providing a physical barrier against pathogens that chemical disinfection alone may not fully eliminate. Hollow fiber membrane modules are commonly used in large-scale installations for their high surface area and continuous operation capability.
Water quality testing and compliance monitoring is a parallel requirement to water treatment itself. Samples must be collected at specified points in the treatment process and analyzed using EPA-approved methods. Syringe filters, membrane filters, and chromatography vials are essential tools in the laboratory analysis that underpins compliance reporting for both drinking water and wastewater discharge permits.
EPA / SDWA
Governing regulatory framework
0.2–0.45 µm
Typical microfiltration pore range
RO & UF
Primary treatment technologies
MCE / PVDF
Preferred compliance testing membranes
Water treatment filtration operates on two tracks: process filtration that physically purifies the water supply, and compliance testing filtration that collects and prepares water samples to verify that treatment is meeting regulatory standards. Both tracks require careful membrane selection to avoid introducing contaminants into the water or the test result.
Water treatment process — step by step
1
Coarse pre-filtration
Sediment, debris, and large particles removed before primary treatment
2
Microfiltration / UF
Bacteria, protozoa, and suspended solids removed by membrane filtration
3
Reverse osmosis
Dissolved salts, heavy metals, and organics removed by RO membrane
4
Disinfection
Chlorination, UV, or ozone treatment eliminates remaining pathogens
5
Compliance testing
Samples filtered and analyzed to confirm MCL compliance before distribution
Key filtration requirements by water treatment application
| Application | Filtration role | Format | Recommended product |
|---|---|---|---|
| RO pre-filtration | Protect RO membrane from fouling | 0.5–5 µm cartridge | Cartridge filters |
| Microfiltration / UF (large scale) | Bacteria and pathogen removal | Hollow fiber, 0.1–0.45 µm | Hollow fiber filters |
| Point-of-use water filtration | Final polishing at distribution point | Capsule or in-line, 0.2 µm | Capsule filters / In-line disk filters |
| Compliance water sampling | 0.45 µm dissolved / particulate split | Syringe or membrane, 0.45 µm | Syringe filters (MCE/PVDF) |
| HPLC / ICP water analysis | Sample prep before analytical column | 0.2 µm syringe filter | Syringe filters / Chromatography vials |
Filter selection tool
Select your water treatment application and scale to get a recommendation.
Membrane compatibility for water treatment
| Membrane | Aqueous compatible | Low extractables | Bacteria retention | Chlorine resistant | EPA water methods |
|---|---|---|---|---|---|
| MCE | |||||
| PVDF | |||||
| PES | |||||
| PTFE | |||||
| Nylon |
Recommended Use with caution Not suitable
Recommended for water treatment
Most used
Hollow Fiber Filters
High surface area TFF modules for large-scale microfiltration and ultrafiltration in municipal and industrial water treatment.
Shop hollow fiber filters →Most used
Syringe Filters
0.45 µm MCE and PVDF for compliance water sampling; 0.2 µm for HPLC sample preparation and trace analysis.
Shop syringe filters →Common
Cartridge Filters
Pre-filtration cartridges for protecting RO membranes and high-throughput water treatment systems.
Shop cartridge filters →Common
Membrane Filters
MCE and PVDF disc filters for vacuum filtration of water samples and microbiological colony counting.
Shop membrane filters →Common
Capsule Filters
Point-of-use and industrial inline water polishing for final-stage 0.2 µm filtration before distribution.
Shop capsule filters →Common
Chromatography Vials
For HPLC and ICP-MS analysis of water contaminants including heavy metals, pesticides, and disinfection byproducts.
Shop chromatography vials →Not sure which product fits your application? Use the Filter Selection Guide tab or contact our technical team.
What is the difference between microfiltration, ultrafiltration, and reverse osmosis in water treatment?+
Microfiltration (0.1–1 µm) removes suspended solids, bacteria, and protozoa while allowing dissolved salts and organics to pass. Ultrafiltration (0.01–0.1 µm / MWCO-based) removes viruses and larger macromolecules in addition to bacteria. Reverse osmosis removes dissolved salts, heavy metals, and most organic compounds using a semi-permeable membrane under pressure. In practice, these processes are often used in sequence: MF/UF for pathogen removal, followed by RO for dissolved contaminant removal.
Why is pre-filtration important before reverse osmosis systems?+
RO membranes are highly sensitive to fouling by suspended particles, biological matter, and scaling compounds. Without adequate pre-filtration, these contaminants accumulate on the RO membrane surface, reducing flux, increasing operating pressure, and shortening membrane life significantly. Cartridge pre-filters rated at 5–20 µm are the standard upstream protection for RO systems in both municipal and industrial water treatment.
What pore size is used for compliance water sampling?+
The EPA defines the 0.45 µm pore size as the operational boundary between dissolved and particulate fractions in water samples. When an EPA method calls for analysis of "dissolved" metals or nutrients, the sample must be filtered through a 0.45 µm membrane filter before analysis. MCE is the most widely specified membrane for this purpose in EPA water methods, though PVDF is used where greater chemical resistance is needed.
What membrane is best for microbiological water testing?+
MCE (Mixed Cellulose Ester) membrane filters at 0.45 µm are the standard for microbiological colony counting in water — including coliform testing under EPA and Standard Methods. Bacteria are retained on the MCE surface where they can be incubated and counted. PVDF membranes are used where greater chemical resistance is needed for the rinse or growth media. Nylon and PTFE are not suitable for microbiological water testing as they can inhibit colony growth.
How does hollow fiber filtration work for large-scale water treatment?+
Hollow fiber modules contain thousands of fine membrane fibers bundled together. Water flows under pressure through the inside of the fibers (inside-out) or over the outside (outside-in), with the membrane wall acting as a selective barrier. Contaminants are retained while clean water permeates through. The high surface area-to-volume ratio makes hollow fiber modules extremely efficient for large-scale water treatment, with continuous operation and periodic backwashing to maintain flux.
Tisch Scientific
Find the right filter
for your application
for your application
Browse hollow fiber filters, syringe filters, cartridge filters, membrane filters, capsule filters, and chromatography vials — all available in the grades and pore sizes needed for water treatment and compliance testing.