Surface water full parameter analysis delivers a comprehensive evaluation of the physical, chemical, biological, and toxicological quality of rivers, lakes, and reservoirs against all 109 indicators specified in GB 3838-2002, Environmental Quality Standards for Surface Water. Accredited third-party laboratories apply standardized sampling protocols and advanced instrumental techniques such as ICP-MS, GC-MS, ion chromatography, and atomic fluorescence spectrometry to classify water quality into Grades I through V. This guide explains the complete scope of parameters, analytical methods, sampling requirements, quality control measures, and practical applications of full-parameter surface water testing.
Technical Overview
Surface water full parameter analysis refers to the systematic determination of every water quality indicator required by the applicable national surface water environmental quality standard, rather than a limited routine subset. In China, the governing framework is GB 3838-2002, Environmental Quality Standards for Surface Water, which defines a total of 109 indicators organized into three tiers:
- 24 basic indicators (Table 1) that are routinely monitored at all sections, covering conventional physicochemical parameters, nutrients, heavy metals, and microbiology.
- 5 supplementary indicators (Table 2), namely sulfate, chloride, nitrate nitrogen, iron, and manganese, applied to centralized drinking water sources and selected monitoring sections.
- 80 specific indicators (Table 3) covering toxic and hazardous substances, including volatile and semi-volatile organics, pesticides, and additional trace elements, monitored at drinking water sources or where specific contamination risks exist.
Based on environmental function and protection objectives, GB 3838-2002 classifies surface water into five quality grades:
- Class I: mainly applicable to source water headwaters and national nature reserves.
- Class II: mainly applicable to first-grade protection zones of centralized drinking water sources, habitats of rare aquatic organisms, and spawning grounds for fish and shrimp.
- Class III: mainly applicable to second-grade protection zones of centralized drinking water sources, wintering grounds for fish and shrimp, migration channels, and aquaculture areas.
- Class IV: mainly applicable to general industrial water use areas and recreational water areas with no direct human contact.
- Class V: mainly applicable to agricultural water use areas and water areas for general landscape requirements.
Full parameter analysis is typically commissioned when a definitive water quality grade determination is required, when a water body is suspected of being affected by complex industrial discharges, or when drinking water source safety must be demonstrated to regulatory authorities. Internationally, comparable programs are supported by ISO water quality standards, ASTM D-series test methods, and the ISO 5667 series on water sampling, allowing results to be harmonized across jurisdictions.
Testing Samples
River Water
River samples are collected at established cross-sections, including upstream reference sections, discharge-affected sections downstream of industrial or municipal outfalls, and convergence sections where tributaries mix with the main stream. Flowing water is sampled at the mid-depth of the main channel, typically 0.2 to 0.5 meters below the surface, away from banks, eddies, and backwater zones. Full parameter campaigns on rivers reveal longitudinal pollution gradients and support total maximum daily load calculations.
Lake and Reservoir Water
Static or slow-moving water bodies are sampled at multiple vertical and horizontal points because pollutants and nutrients stratify with depth and distance from shore. Eutrophication-related indicators such as total nitrogen, total phosphorus, chlorophyll-a, and transparency receive particular attention. Reservoirs serving as drinking water sources usually require evaluation of all 109 GB 3838-2002 indicators at the intake point.
Drinking Water Source Water
Raw water at the intake of water treatment plants must satisfy Class III requirements, and Class II status is encouraged for high-priority sources. Full parameter analysis of source water establishes baseline quality for treatment process design, validates compliance with the supplementary and specific indicator tables, and satisfies the documentation requirements of water source protection zone designation.
Estuarine and Transitional Waters
Where rivers meet the sea, salinity gradients influence the behavior of metals, nutrients, and organics. Sampling programs for transitional waters account for tidal cycles, and salinity is recorded alongside every parameter so that analytical results can be correctly interpreted against freshwater or marine criteria.
Testing Items
The full parameter scope of GB 3838-2002 comprises 109 indicators grouped into functional categories. Representative parameters and their Class III limits include the following:
Physical and General Chemical Indicators
- Water temperature, measured in situ, with a permissible increase of no more than 1 degree Celsius caused by anthropogenic discharge.
- pH value, limited to the range of 6 to 9.
- Sulfate, chloride, nitrate nitrogen, iron, and manganese, the five supplementary indicators.
Oxygen-Balance and Nutrient Indicators
- Dissolved oxygen (DO), with a Class III minimum of 5 mg/L.
- Permanganate index (COD-Mn), Class III limit of 6 mg/L.
- Chemical oxygen demand (COD-Cr), Class III limit of 20 mg/L.
- Five-day biochemical oxygen demand (BOD5), Class III limit of 4 mg/L.
- Ammonia nitrogen (NH3-N), Class III limit of 1.0 mg/L.
- Total nitrogen (TN), Class III limit of 1.0 mg/L.
- Total phosphorus (TP), Class III limit of 0.2 mg/L for rivers and 0.05 mg/L for lakes and reservoirs.
Heavy Metals and Inorganic Toxic Substances
- Copper and zinc, Class III limit of 1.0 mg/L each.
- Fluoride, Class III limit of 1.0 mg/L; selenium, limit of 0.01 mg/L.
- Arsenic, Class III limit of 0.05 mg/L; mercury, limit of 0.0001 mg/L.
- Cadmium, Class III limit of 0.005 mg/L; hexavalent chromium, limit of 0.05 mg/L; lead, limit of 0.05 mg/L.
- Cyanide, Class III limit of 0.2 mg/L; sulfide, limit of 0.2 mg/L.
- Specific-table elements such as antimony, beryllium, molybdenum, nickel, silver, thallium, vanadium, and cobalt at trace-level limits.
Organic Pollutants
- Volatile phenols, Class III limit of 0.005 mg/L; petroleum, limit of 0.05 mg/L.
- Anionic surfactants, Class III limit of 0.2 mg/L.
- Volatile halogenated hydrocarbons such as trichloromethane and carbon tetrachloride.
- Monocyclic aromatics including benzene, toluene, ethylbenzene, xylenes, and styrene.
- Organochlorine and organophosphorus pesticides such as lindane and DDT.
- Polycyclic aromatic hydrocarbons including benzo(a)pyrene, plus phthalate esters, nitrobenzenes, acrylonitrile, acrolein, and formaldehyde.
Microbiological Indicators
- Fecal coliform bacteria, with a Class III limit of 10,000 CFU/L, determined by membrane filtration or multiple-tube fermentation techniques.
- Total coliform bacteria, often included as an extended hygiene indicator for source water risk assessment.
Testing Methods
Sampling and Preservation
Sampling follows HJ 91.2, the technical specification for surface water environmental quality monitoring, together with HJ 493 for sample preservation and management and the ISO 5667 series for internationally harmonized sampling design. Key requirements include:
- In situ measurement of water temperature, pH, dissolved oxygen, electrical conductivity, and transparency at the time of collection.
- Separate pre-cleaned containers for each parameter group: borosilicate glass for organics, polyethylene for metals and general chemistry, and sterile bottles containing sodium thiosulfate for microbiology.
- Acidification with nitric acid to pH below 2 for metals; hydrochloric acid preservation with zero headspace for volatile organics; refrigeration at approximately 4 degrees Celsius for nutrients and biological parameters.
- Respect of maximum holding times, ranging from immediate analysis for DO to 14 days for volatile organics and up to six months for preserved metal samples.
- A total sample volume of typically 10 to 20 liters per station for a complete 109-indicator campaign.
Analytical Techniques and Standard Methods
Accredited third-party laboratories apply the standard methods designated in GB 3838-2002 and its supporting HJ and ISO method standards. Representative pairings include:
- pH by glass electrode method per GB 6920 and ISO 10523; dissolved oxygen by iodometric titration per GB 7489 and ISO 5813 or by electrochemical probe per ISO 5814.
- Permanganate index by the acidic or alkaline permanganate method per GB 11892; COD-Cr by the dichromate reflux method per HJ 828; BOD5 by dilution and seeding per HJ 505 and ISO 5815-1.
- Ammonia nitrogen by Nessler or salicylate spectrophotometry per HJ 535 and HJ 536; total phosphorus by ammonium molybdate spectrophotometry per GB 11893; total nitrogen by alkaline potassium persulfate digestion with UV detection per HJ 636.
- Metals and metalloids by inductively coupled plasma mass spectrometry (ICP-MS) per HJ 700, flame or graphite furnace atomic absorption per GB 7475, and atomic fluorescence spectrometry for mercury, arsenic, selenium, and antimony per HJ 694.
- Hexavalent chromium by diphenylcarbazide spectrophotometry per GB 7467; cyanide per HJ 484; volatile phenols per HJ 503; anionic surfactants per GB 7494; sulfide per GB/T 16489.
- Volatile organic compounds by purge-and-trap or headspace GC-MS per HJ 639 and HJ 810; semi-volatile organics, phthalates, and nitrobenzenes by GC-MS per HJ 834; polycyclic aromatic hydrocarbons by HPLC with fluorescence detection per HJ 478; organochlorine pesticides by gas chromatography with electron capture detection.
- Anions such as sulfate, chloride, and nitrate by ion chromatography per HJ 84.
- Fecal coliform by membrane filtration or enzyme substrate methods per HJ 347.
Quality Assurance and Quality Control
Full parameter campaigns are executed under CMA and CNAS accredited quality systems with documented chain of custody. Essential QA/QC elements include field and laboratory blanks, a minimum duplication rate of 10 percent, matrix spikes and spike recoveries for organic analyses, continuing calibration verification, certified reference materials, and method detection limits no greater than one quarter of the corresponding standard limit. The final report assigns a water quality grade to each indicator and an overall reach classification determined by the worst-performing parameter, providing a defensible basis for regulatory decisions.
Applications
Regulatory Compliance and Polluter Supervision
Environmental authorities use full parameter results to verify whether a water body meets its designated functional zone target, to identify exceedances attributable to specific discharges, and to trigger enforcement actions, pollution remediation plans, or emergency responses following accidental releases.
Drinking Water Source Safety Evaluation
Comprehensive analysis of all 109 indicators at source water intakes confirms Class III compliance or better, screens for trace organic contaminants before they reach treatment plants, and supports the technical justification for establishing or adjusting drinking water protection zones.
Environmental Impact Assessment and Project Approval
Construction projects requiring EIA documentation commission baseline full parameter surveys to characterize pre-project water quality, predict impacts of proposed discharges, and define acceptance criteria for post-construction verification monitoring.
Watershed Management and Scientific Research
Long-term full parameter datasets enable trend analysis, eutrophication modeling, pollutant source apportionment, water quality goal setting under total load control programs, and academic research on the fate and transport of emerging contaminants in aquatic ecosystems.
Industrial and Agricultural Water Use Assessment
Industries evaluating cooling, process, or boiler feed water supplies, and agricultural operations assessing irrigation suitability, rely on complete datasets covering salinity indicators, metals, and toxic organics to determine whether treatment is required before use.
FAQ
Question: What is the difference between full parameter analysis and routine surface water monitoring?
Answer: Routine monitoring covers the 24 basic indicators of GB 3838-2002 Table 1, usually on a monthly cycle. Full parameter analysis extends coverage to all 109 indicators, including the 5 supplementary and 80 specific indicators, and is required for drinking water source evaluation, water quality grade determination, contamination investigations, and periodic comprehensive assessments.
Question: Which surface water quality class is acceptable as a drinking water source?
Answer: Class III is the minimum acceptable grade for centralized drinking water supply sources under GB 3838-2002, with Class II being the preferred target. Water classified as Class IV or Class V requires advanced treatment or is restricted to industrial, agricultural, or landscape uses.
Question: How much sample volume is required and how should it be transported?
Answer: A complete 109-indicator campaign generally requires 10 to 20 liters of water distributed across multiple dedicated containers. Samples must be preserved according to method requirements, such as nitric acid for metals and hydrochloric acid with zero headspace for volatile organics, maintained at approximately 4 degrees Celsius in insulated containers, and delivered to the laboratory within the holding time of the most time-sensitive parameter, ideally within 24 hours of collection.
Question: How long does a full parameter surface water analysis take?
Answer: The 24 basic indicators are typically completed within 5 to 10 working days. A full 109-indicator report usually requires 15 to 20 working days because volatile and semi-volatile organic analyses, pesticide screens, and trace metal determinations involve extended extraction, concentration, and instrument sequences, followed by multi-level data validation.
Question: How is the overall water quality grade determined when individual indicators fall into different classes?
Answer: Each indicator is compared against the grade limits, and the water body is assigned the grade of its worst-performing indicator. This worst-case principle ensures that the reported classification reflects the most restrictive parameter and cannot overstate the suitability of the water for its designated use.