What to test in your water

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Water testing update (7/10/24) - The following water testing services are not eligible for rush testing at this time: Organic chemical rules package, EPA 504: ethylene dibromide (EDB) and dibromochloropropane (DBCP), EPA 505: Chlordane and toxaphene, EPA 505: polychlorinated biphenyls (PCBs) as Aroclors, EPA 525: Semi-volatile organic compounds (SVOCs) and pesticides screen, EPA 525 individual SVOC compound, EPA 525: SVOC screen (non-quantitative).

Common water testing packages

Review the table below and the recommendations column to see what water package best fits your needs.

If you are getting or refinancing a VA/FHA/HUD loan, the Real Estate/VA/HUD test package typically satisfies the lender’s requirements for a private well water test. Verify with your lender. Chemical water testing can take as many as 28 days to complete. Testing can be expedited to result within 14 days of receiving the water samples for a fee. No exceptions will be accommodated. Plan accordingly.

Water testing packages fees

Water package	Supplies per collection location	Tests	Recommendations and notes
Real Estate/HUD package	1 bacteria bottle 1 250 mL metal bottle 1 250 mL neutral bottle	Coliform bacteria, lead, nitrate, and nitrite	This package satisfies most lender’s requests for financing a home loan. Verify with your lender for specific requirements they may have.
Annual Colorado package	1 bacteria bottle 1 250 mL nutrient bottle	Coliform bacteria, nitrate, and nitrite	After getting an initial baseline through the general Colorado package or the deluxe package, the annual Colorado package is recommended on a yearly basis.
Corrosivity - Langelier package	1 250 mL neutral bottle 1 L neutral bottle	Water corrosivity	Langelier index number predicts the scale forming potential of water, which can form a protective barrier of calcium carbonate on the insides of pipes, protecting them from corrosion.
Drilling baseline package	1 250 mL nutrient bottle 1 L neutral bottle 1 250 mL metal bottle 3 40 mL volatile organic compounds (VOC) vials 2 40 mL trip blank vials 1 hydrochloric acid (HCl) dropper	VOC screen, pH, dissolved solids, chloride, fluoride, alkalinity, sulfate, nitrate, nitrite, arsenic, barium, calcium, chromium, iron, magnesium, selenium, sodium, sulfur, and uranium	This package follows the organic testing schedule. Plan accordingly.
General Colorado package	1 bacteria bottle 1 250 mL nutrient bottle 1 250 mL metal bottle 1 fluoride bottle	Arsenic, hardness, coliform bacteria, copper, fluoride, iron, lead, nitrate, nitrite, and uranium	This is the base level of testing recommended for wells with no previous testing performed. Results are evaluated against EPA’s maximum contamination limits (MCLs).
Mining baseline package	1 250 mL nutrient bottle 1 250 mL metal bottle 1 L neutral bottle	Alkalinity, aluminum, arsenic, cadmium, calcium (carbonate), chloride, copper, iron, lead, magnesium, manganese, nitrate, nitrite, pH, potassium, selenium, sodium, sulfate, sulfur, turbidity, and uranium
Sodium-adsorption ratio (SAR) package	1 250 mL metal bottle	Sodium adsorption ratio	An indicator of the suitability of water for use in agricultural irrigation.
Partial regulated inorganic chemicals rule	1 250 mL metal bottle 1 fluoride bottle	Antimony, arsenic, barium, beryllium, cadmium, chromium, fluoride, mercury, nickel, selenium, sodium, thallium	The State Lab does not test for free cyanide, a requirement of the inorganic chemicals rule in Colorado’s Regulation 11.
Groundwater protection baseline	1 bacteria bottle 1 250 mL metal bottle 1 L neutral bottle	Aluminum, antimony, arsenic, barium, beryllium, boron, coliform bacteria, cadmium, chloride, chromium, cobalt, copper, dissolved solids, E. coli,* fluoride, iron, lead, lithium, manganese, molybdenum, nickel, nitrate/nitrite, selenium, silver, sulfate, thallium, total coliform, uranium, vanadium, zinc	This test is intended for compliance with Colorado's Regulation 41. The metals listed with an asterisk are filtered.
Deluxe Colorado package	1 bacteria bottle 1 250 mL nutrient bottle 1 250 mL metal bottle 1 L neutral bottle	Alkalinity, arsenic, cadmium, calcium, coliform bacteria, chloride, conductivity, copper, corrosivity, fluoride, hardness, iron, lead, magnesium, manganese, nitrate, nitrite, pH, sodium, sodium adsorption ratio, sulfate, total dissolved solids, uranium, and zinc	This is the most popular package for obtaining a water quality baseline. Recommended for new wells, wells with an unknown history, or after major events that may affect the water table.
Expanded annual package	1 bacteria bottle 1 250 mL nutrient bottle 1 L neutral bottle	Coliform bacteria, nitrate, nitrite, pH, and total dissolved solids

Specific substance testing

Testing for specific substances in water is available in addition to the common water testing packages listed above. The table below gives an overview of other water testing packages that screen for organic chemicals, inorganic chemicals, individual metals, cyanotoxins, and total coliform.

List of individual substances that can be tested in water and its turnaround times.

Organic compounds contain carbon and hydrogen bonds such as semivolatile organic compounds (SVOCs), volatile organic compounds (VOCs), pesticides, and oil and grease.
Inorganic compounds lack a carbon and hydrogen bond. Examples include nitrogen, chlorine, fluoride, and metals. Inorganic testing also inspects for qualities of a water sample such as alkalinity, turbidity, corrosivity, hardness, pH, UV 254, and presence of solids.
Cyanotoxins are produced by cyanobacteria that contaminate water. The lab can test for total cyanotoxin concentration and for individual concentrations of specific cyanotoxins.
Coliforms are bacteria that are always present in the digestive tracts and waste products of animals, including humans. They are also found in plant and soil material. E. coli is a type of coliform that indicates fecal pollution and potential presence of pathogens.

If you plan to test for organic compounds, these are tested once a month at the lab and follow a specific testing schedule. Cyanotoxin testing occurs only from May through October.

Water package/test	Supplies per collection location	Test	Recommendations and notes
Metals scan package	1 250 mL metal bottle	Aluminum, arsenic, barium, beryllium, cadmium, calcium, chromium, copper, iron, lead, magnesium, manganese, molybdenum, nickel, potassium, selenium, silver, sodium, uranium, zinc
Dewatering testing	1 250 mL metal bottle 1 L neutral bottle	Arsenic, dissolved solids, iron, manganese, selenium, suspended solids, uranium
Total coliform and Esherichia coli (E. coli)	1 bacteria bottle	Most probable number (MPN) and absent/present (A/P) of coliform and E. coli	This testing has a 26 hour hold time. Transport the water sample immediately after collection. Samples that arrive 24 hours after collection will be rejected.

Organics water testing schedule

Organics water testing samples must arrive at the State Lab within the date ranges listed below. CDPHE is not able to test samples received outside of these delivery time frames and must reject them. Specific substances that are subject to this schedule are listed in the table below and in the organics water testing schedule.

Order collection supplies one month in advance. Order only the number of bottles you need for organic water testing. All bottles must be returned to the lab.

January 7-9, 2025
February 4-6, 2025
March 4-6, 2025
April 1-3, 2025
May 6-8, 2025
June 3-5, 2025
July 1-3, 2025
August 5-7, 2025
September 2-4, 2025
October 7-9, 2025
November 4-6, 2025
December 2-4, 2025

Water package/test	Supplies per collection location	Tests	Recommendations and notes
EPA 524: BTEX	3 40 mL VOC vials with ascorbic acid preservative 1 HCl dropper bottle 2 40 mL trip blank vials with acid preservative	Benzene, toluene, ethylbenzene, and total xylenes	Organics water testing follows a specific schedule. Plan accordingly.
EPA 524: TTHMs	3 40 mL VOC vials with ascorbic acid preservative 1 HCl dropper bottle 2 40 mL trip blank vials with acid preservative	Bromodichloromethane, bromoform, chloroform, dibromochloromethane	Organics water testing follows a specific schedule. Plan accordingly.
EPA 524: VOCs	3 40 mL VOC vials with ascorbic acid preservative 1 HCl dropper bottle 2 40 mL trip blank vials with acid preservative	1,1,1-trichloroethane; 1,1,2-trichloroethane; 1,1-dichloroethylene; 1,2,4-trichlorobenzene; 1,2-dichloroethane; 1,2-dichloropropane; benzene, carbon tetrachloride, cis-1,2-Dichloroethene; dichloromethane; ethylbenzene; m,p xylene; monochlorobenzene; o-dichlorobenzene; o-xylene; para-dichlorobenzene; styrene; tetrachloroethene; toluene; trans-1,2-dichloroethylene; trichloroethylene; vinyl chloride	Organics water testing follows a specific schedule. Plan accordingly.
EPA 524: VOC screen	3 40 mL VOC vials with ascorbic acid preservative 1 HCl dropper bottle 2 40 mL trip blank vials with acid preservative	Non-quantitative volatile organic compounds and TTHMs	Organics water testing follows a specific schedule. Plan accordingly.
EPA 525: SVOCs /pesticides	3 1 L SVOC bottles 3 HCl dropper bottles	Hexachlorocyclopentadiene, Hexachlorobenzene, Simazine, Atrazine, Pentachlorophenol, Lindane, Alachlor, Heptachlor, Heptachlor epoxide, Endrin, Di(2-ethylhexyl)phthalate, Methoxychlor, Di(2-ethylhexyl)adipate, Benzo[a]pyrene	Organics water testing follows a specific schedule. Plan accordingly.
EPA 525: SVOC screen	3 1 L SVOC bottles 3 HCl dropper bottles	Non-quantitative semi-volatile organic compounds	Organics water testing follows a specific schedule. Plan accordingly.
EPA 552: Haloacetic acids (HHAs)	3 40 mL TTHM vials with ascorbic acid 2 40 mL trip blank vials 3 40 mL HHA vials with ammonia chloride 1 HCl dropper bottle	Bromoacetic acid, chloroacetic acid, dibromoacetic acid, dichloroacetic acid, trichloroacetic acid	Organics water testing follows a specific schedule. Plan accordingly.
EPA 555: Chlorinated herbicides	1 500 mL herbicide bottle 3 40 mL dalapon vials 1 HCl acid dropper	Picloram, 2,4-D, 2,4,5-TP, Dinoseb, Pentachlorophenol	Organics water testing follows a specific schedule. Plan accordingly.
Organic chemical rules package (SOC package)	1 40 mL carbamate vial 4 40 mL trace vials 3 40 mL VOC vials 2 40 mL trip blank vials 3 40 mL dalapon vials 1 500 mL herbicide bottle 3 1 L SVOC bottles 1 1 L endothall bottle 1 1 L diquat bottle 4 HCl acid droppers	EPA 504-505, EPA 525: SVOCs, EPA 531.2: Carbamates, EPA 547: Glyphosate, EPA 548: Endothall, EPA 549.2: Diquat, EPA 552.2 HAA5 and Dalapon, EPA 555: Herbicides	Organics water testing follows a specific schedule. Plan accordingly.

Cyanotoxin testing and schedule

Cyanotoxins are tested weekly on Thursdays and Fridays, May through October. The water samples must be received by the lab Wednesday before noon. If it is received outside of the water testing schedule, you will be charged double the cost of scheduled testing.

A cyanotoxin water test must be received by the lab within three days of collection. Ship the sample immediately after it is collected.

Enzyme-linked immunosorbent assay (ELISA)

ELISA is used to find the total concentration of microcystins and nodularin (toxins produced by cyanobacteria) in water, the sample. This will analyze for more than 80 types of microcystins and nodularin. Microcystins are commonly produced by Microcystis, Dolichospermum, Planktothrix, Fischerella, Nostoc, Oschillatoria, and Gloetrichia. Nodularins are produced by Nodularia, which is found most commonly in marine or brackish water.

The minimal risk level (MRL) of total cyanotoxins is 0.4 µg/L (ppb).

Liquid chromatography tandem with mass spectrometry (LC-MS/MS)

LC-MS/MS is used to find the individual concentrations of the 11 most common cyanotoxins, which includes eight microcystins, nodularin, anatoxin-a, and cylindrospermopsin. Anatoxin-a is most commonly produced by Anabaena, but some other cyanotoxins are capable of producing it. Cylindrospermopsin are produced by Cylindrospermopsis and aphanizomenon.
The following lists the specific toxins tested by LC-MS/MS. The MRL for all the toxins on this list is 1 µg/L.

Anatoxin-a
Cylindrospermopsin
Nodularin
Microcystin-LA
Microcystin-LF
Microcystin-LR
Microcystin-LW
Microcystin-LY
Microcystin-RR
Microcystin-WR
Microcystin-YR

Cyanotoxin screen using ELISA

A 500 mL amber glass bottle or PETG hard plastic bottle

Total concentration of microcystins and nodularin (cyanotoxins)

This test is recommended if you want to know the total amount of cyanotoxins in your water. This will not test for specific cyanotoxins.

Cyanotoxin testing is available only from May through October and follows a weekly schedule. Plan accordingly.

Cyanotoxin screen using LC-MS/MS